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Mutation & Revalidation – SWR
<!DOCTYPE html><html lang="en"><head><meta charSet="utf-8"/><title>Mutation & Revalidation – SWR</title><meta name="robots" content="index,follow"/><meta property="og:title" content="Mutation & Revalidation – SWR"/><meta name="theme-color" content="#111" media="(prefers-color-scheme: dark)"/><meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover"/><style> :root { --nextra-primary-hue: 212deg; --nextra-navbar-height: 4rem; --nextra-menu-height: 3.75rem; --nextra-banner-height: 2.5rem; } .dark { --nextra-primary-hue: 204deg; } </style><link rel="apple-touch-icon" sizes="180x180" href="/favicon/apple-touch-icon.png"/><link rel="icon" type="image/png" sizes="32x32" href="/favicon/favicon-32x32.png"/><link rel="icon" type="image/png" sizes="16x16" href="/favicon/favicon-16x16.png"/><link rel="icon" type="image/svg+xml" href="/favicon/favicon.svg"/><link rel="manifest" href="/favicon/site.webmanifest"/><link rel="mask-icon" href="/favicon/safari-pinned-tab.svg" color="#000000"/><meta http-equiv="Content-Language" content="en-US, zh-CN, es-ES, fr-FR, pt-BR, ja, ko, ru"/><meta name="msapplication-TileColor" content="#ffffff"/><meta name="apple-mobile-web-app-title" content="SWR"/><meta name="description" content="SWR is a React Hooks library for data fetching. 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dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/api">API</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/global-configuration">Global Configuration</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/data-fetching">Data Fetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/revalidation">Auto Revalidation</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/arguments">Arguments</a></li><li class="nx-flex nx-flex-col nx-gap-1 active"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] 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class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/conditional-fetching">Conditional Data Fetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/pagination">Pagination</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/subscription">Subscription</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/prefetching">Prefetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/with-nextjs">Next.js SSG and SSR</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/typescript">TypeScript</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/suspense">Suspense</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/middleware">Middleware</a></li><li class="open"><button class="nx-items-center nx-justify-between nx-gap-2 nx-text-left nx-w-full nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Advanced<svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-h-[18px] nx-min-w-[18px] nx-rounded-sm nx-p-0.5 hover:nx-bg-gray-800/5 dark:hover:nx-bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="nx-origin-center nx-transition-transform rtl:-nx-rotate-180 ltr:nx-rotate-90 rtl:nx-rotate-[-270deg]"></path></svg></button><div class="nx-transform-gpu nx-overflow-hidden nx-transition-all nx-ease-in-out motion-reduce:nx-transition-none"><div class="nx-transition-opacity nx-duration-500 nx-ease-in-out motion-reduce:nx-transition-none nx-opacity-100 ltr:nx-pr-0 rtl:nx-pl-0 nx-pt-1"><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/understanding">Understanding SWR</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/cache">Cache</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/performance">Performance</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/react-native">React Native</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/devtools">Developer Tools</a></li></ul></div></div></li><li class="nx-flex nx-flex-col nx-gap-1"><a href="https://github.com/vercel/swr/releases" target="_blank" rel="noreferrer" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Change Log<span class="nx-sr-only"> (opens in a new tab)</span></a></li></ul></div></div><ul class="nx-flex nx-flex-col nx-gap-1 md:nx-hidden"><li class="open"><button class="nx-items-center nx-justify-between nx-gap-2 nx-text-left nx-w-full nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Docs<svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-h-[18px] nx-min-w-[18px] nx-rounded-sm nx-p-0.5 hover:nx-bg-gray-800/5 dark:hover:nx-bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="nx-origin-center nx-transition-transform rtl:-nx-rotate-180 ltr:nx-rotate-90 rtl:nx-rotate-[-270deg]"></path></svg></button><div class="nx-transform-gpu nx-overflow-hidden nx-transition-all nx-ease-in-out motion-reduce:nx-transition-none"><div class="nx-transition-opacity nx-duration-500 nx-ease-in-out motion-reduce:nx-transition-none nx-opacity-100 ltr:nx-pr-0 rtl:nx-pl-0 nx-pt-1"><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/getting-started">Getting Started</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/api">API</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/global-configuration">Global Configuration</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/data-fetching">Data Fetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/revalidation">Auto Revalidation</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/arguments">Arguments</a></li><li class="nx-flex nx-flex-col nx-gap-1 active"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-bg-primary-100 nx-font-semibold nx-text-primary-800 dark:nx-bg-primary-400/10 dark:nx-text-primary-600 contrast-more:nx-border-primary-500 contrast-more:dark:nx-border-primary-500" href="/docs/mutation">Mutation & Revalidation</a><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li><a href="#mutate" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">mutate</a></li><li><a href="#useswrmutation" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">useSWRMutation</a></li><li><a href="#optimistic-updates" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Optimistic Updates</a></li><li><a href="#rollback-on-errors" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Rollback on Errors</a></li><li><a href="#update-cache-after-mutation" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Update Cache After Mutation</a></li><li><a href="#avoid-race-conditions" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Avoid Race Conditions</a></li><li><a href="#mutate-based-on-current-data" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Mutate Based on Current Data</a></li><li><a href="#mutate-multiple-items" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-flex nx-gap-2 before:nx-opacity-25 before:nx-content-["#"] nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Mutate Multiple Items</a></li></ul></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/error-handling">Error Handling</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/conditional-fetching">Conditional Data Fetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/pagination">Pagination</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/subscription">Subscription</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/prefetching">Prefetching</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/with-nextjs">Next.js SSG and SSR</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/typescript">TypeScript</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/suspense">Suspense</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/middleware">Middleware</a></li><li class=""><button class="nx-items-center nx-justify-between nx-gap-2 nx-text-left nx-w-full nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Advanced<svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-h-[18px] nx-min-w-[18px] nx-rounded-sm nx-p-0.5 hover:nx-bg-gray-800/5 dark:hover:nx-bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="nx-origin-center nx-transition-transform rtl:-nx-rotate-180"></path></svg></button><div class="nx-transform-gpu nx-overflow-hidden nx-transition-all nx-ease-in-out motion-reduce:nx-transition-none" style="height:0"><div class="nx-transition-opacity nx-duration-500 nx-ease-in-out motion-reduce:nx-transition-none nx-opacity-0 ltr:nx-pr-0 rtl:nx-pl-0 nx-pt-1"><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/understanding">Understanding SWR</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/cache">Cache</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/performance">Performance</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/react-native">React Native</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/docs/advanced/devtools">Developer Tools</a></li></ul></div></div></li><li class="nx-flex nx-flex-col nx-gap-1"><a href="https://github.com/vercel/swr/releases" target="_blank" rel="noreferrer" class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Change Log<span class="nx-sr-only"> (opens in a new tab)</span></a></li></ul></div></div></li><li class="open"><button class="nx-items-center nx-justify-between nx-gap-2 nx-text-left nx-w-full nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50">Examples<svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-h-[18px] nx-min-w-[18px] nx-rounded-sm nx-p-0.5 hover:nx-bg-gray-800/5 dark:hover:nx-bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="nx-origin-center nx-transition-transform rtl:-nx-rotate-180 ltr:nx-rotate-90 rtl:nx-rotate-[-270deg]"></path></svg></button><div class="nx-transform-gpu nx-overflow-hidden nx-transition-all nx-ease-in-out motion-reduce:nx-transition-none"><div class="nx-transition-opacity nx-duration-500 nx-ease-in-out motion-reduce:nx-transition-none nx-opacity-100 ltr:nx-pr-0 rtl:nx-pl-0 nx-pt-1"><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/basic">Basic Usage</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/auth">Authentication</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/optimistic-ui">Optimistic UI</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/infinite-loading">Infinite Loading</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/error-handling">Error Handling</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/ssr">Next.js SSR</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/examples/subscription">Subscription</a></li></ul></div></div></li><li class="open"><a class="nx-items-center nx-justify-between nx-gap-2 nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/blog">Blog<svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-h-[18px] nx-min-w-[18px] nx-rounded-sm nx-p-0.5 hover:nx-bg-gray-800/5 dark:hover:nx-bg-gray-100/5"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" class="nx-origin-center nx-transition-transform rtl:-nx-rotate-180 ltr:nx-rotate-90 rtl:nx-rotate-[-270deg]"></path></svg></a><div class="nx-transform-gpu nx-overflow-hidden nx-transition-all nx-ease-in-out motion-reduce:nx-transition-none"><div class="nx-transition-opacity nx-duration-500 nx-ease-in-out motion-reduce:nx-transition-none nx-opacity-100 ltr:nx-pr-0 rtl:nx-pl-0 nx-pt-1"><ul class="nx-flex nx-flex-col nx-gap-1 nx-relative before:nx-absolute before:nx-inset-y-1 before:nx-w-px before:nx-bg-gray-200 before:nx-content-[""] dark:before:nx-bg-neutral-800 ltr:nx-pl-3 ltr:before:nx-left-0 rtl:nx-pr-3 rtl:before:nx-right-0 ltr:nx-ml-3 rtl:nx-mr-3"><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/blog/swr-v2">Announcing SWR 2.0</a></li><li class="nx-flex nx-flex-col nx-gap-1"><a class="nx-flex nx-rounded nx-px-2 nx-py-1.5 nx-text-sm nx-transition-colors [word-break:break-word] nx-cursor-pointer [-webkit-tap-highlight-color:transparent] [-webkit-touch-callout:none] contrast-more:nx-border nx-text-gray-500 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:nx-text-neutral-500 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50 contrast-more:nx-text-gray-900 contrast-more:dark:nx-text-gray-50 contrast-more:nx-border-transparent contrast-more:hover:nx-border-gray-900 contrast-more:dark:hover:nx-border-gray-50" href="/blog/swr-v1">Announcing SWR 1.0</a></li></ul></div></div></li></ul></div><div class="nx-sticky nx-bottom-0 nx-bg-white dark:nx-bg-dark nx-mx-4 nx-py-4 nx-shadow-[0_-12px_16px_#fff] nx-flex nx-items-center nx-gap-2 dark:nx-border-neutral-800 dark:nx-shadow-[0_-12px_16px_#111] contrast-more:nx-border-neutral-400 contrast-more:nx-shadow-none contrast-more:dark:nx-shadow-none nx-justify-end 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3.556.24.56.5.948.737 1.182.233.23.389.262.465.262.076 0 .232-.032.465-.262.238-.234.498-.623.737-1.182.389-.907.673-2.142.766-3.556zm1.166 4.118c.454-1.147.748-2.572.837-4.118h1.946a6.004 6.004 0 01-2.783 4.118zm-6.268 0C6.412 13.97 6.118 12.546 6.03 11H4.083a6.004 6.004 0 002.783 4.118z" clip-rule="evenodd"></path></svg><span class="">English</span></span></button><div class=""><button title="Change theme" class="nx-h-7 nx-rounded-md nx-px-2 nx-text-left nx-text-xs nx-font-medium nx-text-gray-600 nx-transition-colors dark:nx-text-gray-400 hover:nx-bg-gray-100 hover:nx-text-gray-900 dark:hover:nx-bg-primary-100/5 dark:hover:nx-text-gray-50" id="headlessui-listbox-button-:R2njcm:" type="button" aria-haspopup="listbox" aria-expanded="false" data-headlessui-state=""><div class="nx-flex nx-items-center nx-gap-2 nx-capitalize"><svg fill="none" viewBox="3 3 18 18" width="12" height="12" stroke="currentColor"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" fill="currentColor" d="M12 3v1m0 16v1m9-9h-1M4 12H3m15.364 6.364l-.707-.707M6.343 6.343l-.707-.707m12.728 0l-.707.707M6.343 17.657l-.707.707M16 12a4 4 0 11-8 0 4 4 0 018 0z"></path></svg><span class="md:nx-hidden">Light</span></div></button></div></div></aside><nav class="nextra-toc nx-order-last nx-hidden nx-w-64 nx-shrink-0 xl:nx-block print:nx-hidden nx-px-4" aria-label="table of contents"><div class="nextra-scrollbar nx-sticky nx-top-16 nx-overflow-y-auto nx-pr-4 nx-pt-6 nx-text-sm [hyphens:auto] nx-max-h-[calc(100vh-var(--nextra-navbar-height)-env(safe-area-inset-bottom))] ltr:-nx-mr-4 rtl:-nx-ml-4"><p class="nx-mb-4 nx-font-semibold nx-tracking-tight">On This Page</p><ul><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#mutate" class="nx-font-semibold nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">mutate</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#global-mutate" class="ltr:nx-pl-8 rtl:nx-pr-8 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Global Mutate</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#bound-mutate" class="ltr:nx-pl-8 rtl:nx-pr-8 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Bound Mutate</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#revalidation" class="ltr:nx-pl-8 rtl:nx-pr-8 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Revalidation</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#api" class="ltr:nx-pl-4 rtl:nx-pr-4 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">API</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#parameters" class="ltr:nx-pl-8 rtl:nx-pr-8 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Parameters</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#return-values" class="ltr:nx-pl-8 rtl:nx-pr-8 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Return Values</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#useswrmutation" class="nx-font-semibold nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">useSWRMutation</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#useswrmutation-api" class="ltr:nx-pl-4 rtl:nx-pr-4 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">API</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#useswrmutation-parameters" class="ltr:nx-pl-8 rtl:nx-pr-8 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Parameters</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#useswrmutation-return-values" class="ltr:nx-pl-8 rtl:nx-pr-8 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Return Values</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#useswrmutation-basic-usage" class="ltr:nx-pl-4 rtl:nx-pr-4 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Basic Usage</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#defer-loading-data-until-needed" class="ltr:nx-pl-4 rtl:nx-pr-4 nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Defer loading data until needed</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#optimistic-updates" class="nx-font-semibold nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Optimistic Updates</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#rollback-on-errors" class="nx-font-semibold nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Rollback on Errors</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#update-cache-after-mutation" class="nx-font-semibold nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Update Cache After Mutation</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#avoid-race-conditions" class="nx-font-semibold nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Avoid Race Conditions</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#mutate-based-on-current-data" class="nx-font-semibold nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Mutate Based on Current Data</a></li><li class="nx-my-2 nx-scroll-my-6 nx-scroll-py-6"><a href="#mutate-multiple-items" class="nx-font-semibold nx-inline-block nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-300 contrast-more:nx-text-gray-900 contrast-more:nx-underline contrast-more:dark:nx-text-gray-50 nx-w-full nx-break-words">Mutate Multiple Items</a></li></ul><div class="nx-mt-8 nx-border-t nx-bg-white nx-pt-8 nx-shadow-[0_-12px_16px_white] dark:nx-bg-dark dark:nx-shadow-[0_-12px_16px_#111] nx-sticky nx-bottom-0 nx-flex nx-flex-col nx-items-start nx-gap-2 nx-pb-8 dark:nx-border-neutral-800 contrast-more:nx-border-t contrast-more:nx-border-neutral-400 contrast-more:nx-shadow-none contrast-more:dark:nx-border-neutral-400"><a href="https://github.com/vercel/swr-site/issues/new?title=Feedback%20for%20%E2%80%9CMutation%20%26%20Revalidation%E2%80%9D&labels=feedback" target="_blank" rel="noreferrer" class="nx-text-xs nx-font-medium nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-100 contrast-more:nx-text-gray-800 contrast-more:dark:nx-text-gray-50">Question? Give us feedback →<span class="nx-sr-only"> (opens in a new tab)</span></a><a class="nx-text-xs nx-font-medium nx-text-gray-500 hover:nx-text-gray-900 dark:nx-text-gray-400 dark:hover:nx-text-gray-100 contrast-more:nx-text-gray-800 contrast-more:dark:nx-text-gray-50" href="https://github.com/vercel/swr-site/blob/main/pages/docs/mutation.en-US.mdx">Edit this page on GitHub →</a></div></div></nav><div id="reach-skip-nav"></div><article class="nx-w-full nx-break-words nextra-content nx-flex nx-min-h-[calc(100vh-var(--nextra-navbar-height))] nx-min-w-0 nx-justify-center nx-pb-8 nx-pr-[calc(env(safe-area-inset-right)-1.5rem)]"><main class="nx-w-full nx-min-w-0 nx-max-w-6xl nx-px-6 nx-pt-4 md:nx-px-12"><div class="nextra-breadcrumb nx-mt-1.5 nx-flex nx-items-center nx-gap-1 nx-overflow-hidden nx-text-sm nx-text-gray-500 contrast-more:nx-text-current"><div class="nx-whitespace-nowrap nx-transition-colors nx-min-w-[24px] nx-overflow-hidden nx-text-ellipsis" title="Docs">Docs</div><svg fill="none" viewBox="0 0 24 24" stroke="currentColor" class="nx-w-3.5 nx-shrink-0"><path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7"></path></svg><div class="nx-whitespace-nowrap nx-transition-colors nx-font-medium nx-text-gray-700 contrast-more:nx-font-bold contrast-more:nx-text-current dark:nx-text-gray-400 contrast-more:dark:nx-text-current" title="Mutation & Revalidation">Mutation & Revalidation</div></div><h1 class="nx-mt-2 nx-text-4xl nx-font-bold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100">Mutation & Revalidation</h1> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">SWR provides the <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/mutation#mutate"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code></a> and <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/mutation#useswrmutation"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code></a> APIs for mutating remote data and related cache.</p> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code><span class="nx-absolute -nx-mt-20" id="mutate"></span><a href="#mutate" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">There're 2 ways to use the <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code> API to mutate the data, the global mutate API which can mutate any key and the bound mutate API which only can mutate the data of corresponding SWR hook.</p> <h4 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-xl">Global Mutate<span class="nx-absolute -nx-mt-20" id="global-mutate"></span><a href="#global-mutate" class="subheading-anchor" aria-label="Permalink for this section"></a></h4> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">The recommended way to get the global mutator is to use the <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/global-configuration#access-to-global-configurations"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRConfig</code></a> hook:</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="js" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="js" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> { useSWRConfig } </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">"swr"</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">App</span><span style="color:var(--shiki-color-text)">() {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">mutate</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRConfig</span><span style="color:var(--shiki-color-text)">()</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(key</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> data</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> options)</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">You can also import it globally:</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="js" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="js" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> { mutate } </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">"swr"</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">App</span><span style="color:var(--shiki-color-text)">() {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(key</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> data</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> options)</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <div class="nextra-callout nx-overflow-x-auto nx-mt-6 nx-flex nx-rounded-lg nx-border nx-py-2 ltr:nx-pr-4 rtl:nx-pl-4 contrast-more:nx-border-current contrast-more:dark:nx-border-current nx-border-orange-100 nx-bg-orange-50 nx-text-orange-800 dark:nx-border-orange-400/30 dark:nx-bg-orange-400/20 dark:nx-text-orange-300"><div class="nx-select-none nx-text-xl ltr:nx-pl-3 ltr:nx-pr-2 rtl:nx-pr-3 rtl:nx-pl-2" style="font-family:"Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol"">⚠️</div><div class="nx-w-full nx-min-w-0 nx-leading-7"><p class="nx-mt-6 nx-leading-7 first:nx-mt-0">Using global mutator only with the <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">key</code> parameter will <em><strong>not update the cache or trigger revalidation</strong></em> unless there is a mounted SWR hook using the same key.</p></div></div> <h4 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-xl">Bound Mutate<span class="nx-absolute -nx-mt-20" id="bound-mutate"></span><a href="#bound-mutate" class="subheading-anchor" aria-label="Permalink for this section"></a></h4> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">Bound mutate is the short path to mutate the current key with data. Which <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">key</code> is bounded to the <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">key</code> passing to <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWR</code>, and receive the <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">data</code> as the first argument.</p> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">It is functionally equivalent to the global <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code> function in the previous section but does not require the <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">key</code> parameter:</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> useSWR </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'swr'</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">Profile</span><span style="color:var(--shiki-color-text)"> () {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">mutate</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWR</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> fetcher)</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> (</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">h1</span><span style="color:var(--shiki-color-text)">>My name is {</span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-color-text)">.name}.</</span><span style="color:var(--shiki-token-string-expression)">h1</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">onClick</span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)">{</span><span style="color:var(--shiki-token-keyword)">async</span><span style="color:var(--shiki-color-text)"> () </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">newName</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-token-function)">.</span><span style="color:var(--shiki-token-constant)">name</span><span style="color:var(--shiki-token-function)">.toUpperCase</span><span style="color:var(--shiki-color-text)">()</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// send a request to the API to update the data</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">await</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">requestUpdateUsername</span><span style="color:var(--shiki-color-text)">(newName)</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// update the local data immediately and revalidate (refetch)</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// NOTE: key is not required when using useSWR's mutate as it's pre-bound</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">({ </span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">data</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> name</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> newName })</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }}>Uppercase my name!</</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> )</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <h4 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-xl">Revalidation<span class="nx-absolute -nx-mt-20" id="revalidation"></span><a href="#revalidation" class="subheading-anchor" aria-label="Permalink for this section"></a></h4> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">When you call <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate(key)</code> (or just <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate()</code> with the bound mutate API) without any data, it will trigger a revalidation (mark the data as expired and trigger a refetch) for the resource. This example shows how to automatically refetch the login info (e.g. inside <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr"><Profile/></code>) when the user clicks the “Logout” button:</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> useSWR</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> { useSWRConfig } </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'swr'</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">App</span><span style="color:var(--shiki-color-text)"> () {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">mutate</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRConfig</span><span style="color:var(--shiki-color-text)">()</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> (</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-constant)">Profile</span><span style="color:var(--shiki-color-text)"> /></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">onClick</span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)">{() </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// set the cookie as expired</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">document</span><span style="color:var(--shiki-color-text)">.cookie </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'token=; expires=Thu, 01 Jan 1970 00:00:00 UTC; path=/;'</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// tell all SWRs with this key to revalidate</span></span> <span class="line highlighted"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }}></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> Logout</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> )</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <div class="nextra-callout nx-overflow-x-auto nx-mt-6 nx-flex nx-rounded-lg nx-border nx-py-2 ltr:nx-pr-4 rtl:nx-pl-4 contrast-more:nx-border-current contrast-more:dark:nx-border-current nx-border-orange-100 nx-bg-orange-50 nx-text-orange-800 dark:nx-border-orange-400/30 dark:nx-bg-orange-400/20 dark:nx-text-orange-300"><div class="nx-select-none nx-text-xl ltr:nx-pl-3 ltr:nx-pr-2 rtl:nx-pr-3 rtl:nx-pl-2" style="font-family:"Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol"">💡</div><div class="nx-w-full nx-min-w-0 nx-leading-7"><p class="nx-mt-6 nx-leading-7 first:nx-mt-0">It broadcasts to SWR hooks under the same <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/advanced/cache">cache provider</a> scope. If no cache provider exists, it will broadcast to all SWR hooks.</p></div></div> <h3 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-2xl">API<span class="nx-absolute -nx-mt-20" id="api"></span><a href="#api" class="subheading-anchor" aria-label="Permalink for this section"></a></h3> <h4 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-xl">Parameters<span class="nx-absolute -nx-mt-20" id="parameters"></span><a href="#parameters" class="subheading-anchor" aria-label="Permalink for this section"></a></h4> <ul class="nx-mt-6 nx-list-disc first:nx-mt-0 ltr:nx-ml-6 rtl:nx-mr-6"> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">key</code>: same as <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWR</code>'s <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">key</code>, but a function behaves as <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/mutation#mutate-multiple-items">a filter function</a></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">data</code>: data to update the client cache, or an async function for the remote mutation</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">options</code>: accepts the following options<!-- --> <ul class="nx-mt-6 nx-list-disc first:nx-mt-0 ltr:nx-ml-6 rtl:nx-mr-6"> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">optimisticData</code>: data to immediately update the client cache, or a function that receives current data and returns the new client cache data, usually used in optimistic UI.</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">revalidate = true</code>: should the cache revalidate once the asynchronous update resolves. If set to a function, the function receives <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">data</code> and <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">key</code>.</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">populateCache = true</code>: should the result of the remote mutation be written to the cache, or a function that receives new result and current result as arguments and returns the mutation result.</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">rollbackOnError = true</code>: should the cache rollback if the remote mutation errors, or a function that receives the error thrown from fetcher as arguments and returns a boolean whether should rollback or not.</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">throwOnError = true</code>: should the mutate call throw the error when fails.</li> </ul> </li> </ul> <h4 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-xl">Return Values<span class="nx-absolute -nx-mt-20" id="return-values"></span><a href="#return-values" class="subheading-anchor" aria-label="Permalink for this section"></a></h4> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code> returns the results the <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">data</code> parameter has been resolved. The function passed to <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code> will return an updated data which is used to update the corresponding cache value. If there is an error thrown while executing the function, the error will be thrown so it can be handled appropriately.</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">try</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">user</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">await</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">updateUser</span><span style="color:var(--shiki-color-text)">(newUser))</span></span> <span class="line"><span style="color:var(--shiki-color-text)">} </span><span style="color:var(--shiki-token-keyword)">catch</span><span style="color:var(--shiki-color-text)"> (error) {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// Handle an error while updating the user here</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code><span class="nx-absolute -nx-mt-20" id="useswrmutation"></span><a href="#useswrmutation" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">SWR also provides <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code> as a hook for remote mutations. The remote mutations are only triggered manually, instead of automatically like <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWR</code>.</p> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">Also, this hook doesn’t share states with other <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code> hooks.</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="tsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="tsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> useSWRMutation </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'swr/mutation'</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-comment)">// Fetcher implementation.</span></span> <span class="line"><span style="color:var(--shiki-token-comment)">// The extra argument will be passed via the `arg` property of the 2nd parameter.</span></span> <span class="line"><span style="color:var(--shiki-token-comment)">// In the example below, `arg` will be `'my_token'`</span></span> <span class="line"><span style="color:var(--shiki-token-keyword)">async</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">updateUser</span><span style="color:var(--shiki-color-text)">(url</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> { arg }</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> { arg</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">string</span><span style="color:var(--shiki-color-text)"> }) {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">await</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">fetch</span><span style="color:var(--shiki-color-text)">(url</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> method</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'POST'</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> headers</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> Authorization</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">`Bearer </span><span style="color:var(--shiki-token-keyword)">${</span><span style="color:var(--shiki-color-text)">arg</span><span style="color:var(--shiki-token-keyword)">}</span><span style="color:var(--shiki-token-string-expression)">`</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> })</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">Profile</span><span style="color:var(--shiki-color-text)">() {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// A useSWR + mutate like API, but it will not start the request automatically.</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">trigger</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRMutation</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> updateUser</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> options)</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">onClick</span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)">{() </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// Trigger `updateUser` with a specific argument.</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">trigger</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'my_token'</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }}>Update User</</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <h3 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-2xl">API<span class="nx-absolute -nx-mt-20" id="useswrmutation-api"></span><a href="#useswrmutation-api" class="subheading-anchor" aria-label="Permalink for this section"></a></h3> <h4 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-xl">Parameters<span class="nx-absolute -nx-mt-20" id="useswrmutation-parameters"></span><a href="#useswrmutation-parameters" class="subheading-anchor" aria-label="Permalink for this section"></a></h4> <ul class="nx-mt-6 nx-list-disc first:nx-mt-0 ltr:nx-ml-6 rtl:nx-mr-6"> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">key</code>: same as <a class="nx-text-primary-600 nx-underline nx-decoration-from-font [text-underline-position:from-font]" href="/docs/mutation#mutate"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code></a>'s <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">key</code></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">fetcher(key, { arg })</code>: an async function for remote mutation</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">options</code>: an optional object with the following properties:<!-- --> <ul class="nx-mt-6 nx-list-disc first:nx-mt-0 ltr:nx-ml-6 rtl:nx-mr-6"> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">optimisticData</code>: same as <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code>'s <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">optimisticData</code></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">revalidate = true</code>: same as <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code>'s <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">revalidate</code></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">populateCache = false</code>: same as <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code>'s <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">populateCache</code>, but the default is <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">false</code></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">rollbackOnError = true</code>: same as <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code>'s <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">rollbackOnError</code></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">throwOnError = true</code>: same as <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code>'s <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">throwOnError</code></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">onSuccess(data, key, config)</code>: callback function when a remote mutation has been finished successfully</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">onError(err, key, config)</code>: callback function when a remote mutation has returned an error</li> </ul> </li> </ul> <h4 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-xl">Return Values<span class="nx-absolute -nx-mt-20" id="useswrmutation-return-values"></span><a href="#useswrmutation-return-values" class="subheading-anchor" aria-label="Permalink for this section"></a></h4> <ul class="nx-mt-6 nx-list-disc first:nx-mt-0 ltr:nx-ml-6 rtl:nx-mr-6"> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">data</code>: data for the given key returned from <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">fetcher</code></li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">error</code>: error thrown by <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">fetcher</code> (or undefined)</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">trigger(arg, options)</code>: a function to trigger a remote mutation</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">reset</code>: a function to reset the state (<code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">data</code>, <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">error</code>, <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">isMutating</code>)</li> <li class="nx-my-2"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">isMutating</code>: if there's an ongoing remote mutation</li> </ul> <h3 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-2xl">Basic Usage<span class="nx-absolute -nx-mt-20" id="useswrmutation-basic-usage"></span><a href="#useswrmutation-basic-usage" class="subheading-anchor" aria-label="Permalink for this section"></a></h3> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="tsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="tsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> useSWRMutation </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'swr/mutation'</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">async</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">sendRequest</span><span style="color:var(--shiki-color-text)">(url</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> { arg }</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> { arg</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> { username</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">string</span><span style="color:var(--shiki-color-text)"> }}) {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">fetch</span><span style="color:var(--shiki-color-text)">(url</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> method</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'POST'</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> body</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">JSON</span><span style="color:var(--shiki-token-function)">.stringify</span><span style="color:var(--shiki-color-text)">(arg)</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> })</span><span style="color:var(--shiki-token-function)">.then</span><span style="color:var(--shiki-color-text)">(res </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">res</span><span style="color:var(--shiki-token-function)">.json</span><span style="color:var(--shiki-color-text)">())</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">App</span><span style="color:var(--shiki-color-text)">() {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">trigger</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">isMutating</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRMutation</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> sendRequest</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">/* options */</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> (</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">button</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">disabled</span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)">{isMutating}</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">onClick</span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)">{</span><span style="color:var(--shiki-token-keyword)">async</span><span style="color:var(--shiki-color-text)"> () </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">try</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">result</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">await</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">trigger</span><span style="color:var(--shiki-color-text)">({ username</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'johndoe'</span><span style="color:var(--shiki-color-text)"> }</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">/* options */</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">catch</span><span style="color:var(--shiki-color-text)"> (e) {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// error handling</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }}</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> ></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> Create User</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> )</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">If you want to use the mutation results in rendering, you can get them from the return values of <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code>.</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">trigger</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">error</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRMutation</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> sendRequest)</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code> shares a cache store with <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWR</code>, so it can detect and avoid race conditions between <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWR</code>. It also supports <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code>'s functionalities like optimistic updates and rollback on errors. You can pass these options <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code> and its <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">trigger</code> function.</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">trigger</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRMutation</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> updateUser</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">optimisticData</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> current </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> ({ </span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">current</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> name</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> newName })</span></span> <span class="line"><span style="color:var(--shiki-color-text)">})</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-comment)">// or</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-function)">trigger</span><span style="color:var(--shiki-color-text)">(newName</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">optimisticData</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> current </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> ({ </span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">current</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> name</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> newName })</span></span> <span class="line"><span style="color:var(--shiki-color-text)">})</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <h3 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-8 nx-text-2xl">Defer loading data until needed<span class="nx-absolute -nx-mt-20" id="defer-loading-data-until-needed"></span><a href="#defer-loading-data-until-needed" class="subheading-anchor" aria-label="Permalink for this section"></a></h3> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">You can also use <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code> for loading data. <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code> won't start requesting until <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">trigger</code> is called, so you can defer loading data when you actually need it.</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> { useState } </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'react'</span></span> <span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> useSWRMutation </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'swr/mutation'</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">fetcher</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> url </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">fetch</span><span style="color:var(--shiki-color-text)">(url)</span><span style="color:var(--shiki-token-function)">.then</span><span style="color:var(--shiki-color-text)">(res </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">res</span><span style="color:var(--shiki-token-function)">.json</span><span style="color:var(--shiki-color-text)">())</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">Page</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> () </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> [</span><span style="color:var(--shiki-token-constant)">show</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">setShow</span><span style="color:var(--shiki-color-text)">] </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useState</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-constant)">false</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// data is undefined until trigger is called</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { data: </span><span style="color:var(--shiki-token-constant)">user</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">trigger</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRMutation</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> fetcher);</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> (</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">onClick</span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)">{() </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">trigger</span><span style="color:var(--shiki-color-text)">();</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">setShow</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-constant)">true</span><span style="color:var(--shiki-color-text)">);</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }}>Show User</</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> {show </span><span style="color:var(--shiki-token-keyword)">&&</span><span style="color:var(--shiki-color-text)"> user </span><span style="color:var(--shiki-token-keyword)">?</span><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">>{</span><span style="color:var(--shiki-token-constant)">user</span><span style="color:var(--shiki-color-text)">.name}</</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">> </span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">null</span><span style="color:var(--shiki-color-text)">}</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> );</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400">Optimistic Updates<span class="nx-absolute -nx-mt-20" id="optimistic-updates"></span><a href="#optimistic-updates" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">In many cases, applying local mutations to data is a good way to make changes feel faster — no need to wait for the remote source of data.</p> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">With the <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">optimisticData</code> option, you can update your local data manually, while waiting for the remote mutation to finish. Composing <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">rollbackOnError</code> you can also control when to rollback the data.</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> useSWR</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> { useSWRConfig } </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'swr'</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">Profile</span><span style="color:var(--shiki-color-text)"> () {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">mutate</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRConfig</span><span style="color:var(--shiki-color-text)">()</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWR</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> fetcher)</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> (</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">h1</span><span style="color:var(--shiki-color-text)">>My name is {</span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-color-text)">.name}.</</span><span style="color:var(--shiki-token-string-expression)">h1</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">onClick</span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)">{</span><span style="color:var(--shiki-token-keyword)">async</span><span style="color:var(--shiki-color-text)"> () </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">newName</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-token-function)">.</span><span style="color:var(--shiki-token-constant)">name</span><span style="color:var(--shiki-token-function)">.toUpperCase</span><span style="color:var(--shiki-color-text)">()</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">user</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">data</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> name</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> newName }</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">options</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> optimisticData</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> user</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">rollbackOnError</span><span style="color:var(--shiki-color-text)">(error) {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// If it's timeout abort error, don't rollback</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">error</span><span style="color:var(--shiki-color-text)">.name </span><span style="color:var(--shiki-token-keyword)">!==</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'AbortError'</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// updates the local data immediately</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// send a request to update the data</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// triggers a revalidation (refetch) to make sure our local data is correct</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">updateFn</span><span style="color:var(--shiki-color-text)">(user)</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> options);</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }}>Uppercase my name!</</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> )</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <blockquote class="nx-mt-6 nx-border-gray-300 nx-italic nx-text-gray-700 dark:nx-border-gray-700 dark:nx-text-gray-400 first:nx-mt-0 ltr:nx-border-l-2 ltr:nx-pl-6 rtl:nx-border-r-2 rtl:nx-pr-6"> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">The <strong><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">updateFn</code></strong> should be a promise or asynchronous function to handle the remote mutation, it should return updated data.</p> </blockquote> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">You can also pass a function to <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">optimisticData</code> to make it depending on the current data:</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> useSWR</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> { useSWRConfig } </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'swr'</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">Profile</span><span style="color:var(--shiki-color-text)"> () {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">mutate</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRConfig</span><span style="color:var(--shiki-color-text)">()</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWR</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> fetcher)</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> (</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">h1</span><span style="color:var(--shiki-color-text)">>My name is {</span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-color-text)">.name}.</</span><span style="color:var(--shiki-token-string-expression)">h1</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">onClick</span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)">{</span><span style="color:var(--shiki-token-keyword)">async</span><span style="color:var(--shiki-color-text)"> () </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">newName</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-token-function)">.</span><span style="color:var(--shiki-token-constant)">name</span><span style="color:var(--shiki-token-function)">.toUpperCase</span><span style="color:var(--shiki-color-text)">()</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">updateUserName</span><span style="color:var(--shiki-color-text)">(newName)</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">optimisticData</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> user </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> ({ </span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">user</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> name</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> newName })</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> rollbackOnError</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">true</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> });</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }}>Uppercase my name!</</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> )</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">You can also create the same thing with <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code> and <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">trigger</code>:</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> useSWRMutation </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'swr/mutation'</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">Profile</span><span style="color:var(--shiki-color-text)"> () {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">trigger</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRMutation</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> updateUserName)</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> (</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">h1</span><span style="color:var(--shiki-color-text)">>My name is {</span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-color-text)">.name}.</</span><span style="color:var(--shiki-token-string-expression)">h1</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">onClick</span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)">{</span><span style="color:var(--shiki-token-keyword)">async</span><span style="color:var(--shiki-color-text)"> () </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">newName</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-token-function)">.</span><span style="color:var(--shiki-token-constant)">name</span><span style="color:var(--shiki-token-function)">.toUpperCase</span><span style="color:var(--shiki-color-text)">()</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">trigger</span><span style="color:var(--shiki-color-text)">(newName</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">optimisticData</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> user </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> ({ </span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">user</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> name</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> newName })</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> rollbackOnError</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">true</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> })</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }}>Uppercase my name!</</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </</span><span style="color:var(--shiki-token-string-expression)">div</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> )</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400">Rollback on Errors<span class="nx-absolute -nx-mt-20" id="rollback-on-errors"></span><a href="#rollback-on-errors" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">When you have <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">optimisticData</code> set, it’s possible that the optimistic data gets displayed to the user, but the remote mutation fails. In this case, you can leverage <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">rollbackOnError</code> to revert the local cache to the previous state, to make sure the user is seeing the correct data.</p> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400">Update Cache After Mutation<span class="nx-absolute -nx-mt-20" id="update-cache-after-mutation"></span><a href="#update-cache-after-mutation" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">Sometimes, the remote mutation request directly returns the updated data, so there is no need to do an extra fetch to load it. You can enable the <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">populateCache</code> option to update the cache for <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWR</code> with the response of the mutation:</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">updateTodo</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> () </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">fetch</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/todos/1'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> method</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'PATCH'</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> body</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">JSON</span><span style="color:var(--shiki-token-function)">.stringify</span><span style="color:var(--shiki-color-text)">({ completed</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">true</span><span style="color:var(--shiki-color-text)"> })</span></span> <span class="line"><span style="color:var(--shiki-color-text)">})</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/todos'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> updateTodo</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">populateCache</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> (updatedTodo</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> todos) </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// filter the list, and return it with the updated item</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">filteredTodos</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">todos</span><span style="color:var(--shiki-token-function)">.filter</span><span style="color:var(--shiki-color-text)">(todo </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">todo</span><span style="color:var(--shiki-color-text)">.id </span><span style="color:var(--shiki-token-keyword)">!==</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'1'</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> [</span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">filteredTodos</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> updatedTodo]</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// Since the API already gives us the updated information,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// we don't need to revalidate here.</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> revalidate</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">false</span></span> <span class="line"><span style="color:var(--shiki-color-text)">})</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">Or with the <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code> hook:</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-function)">useSWRMutation</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/todos'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> updateTodo</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">populateCache</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> (updatedTodo</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> todos) </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// filter the list, and return it with the updated item</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">filteredTodos</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">todos</span><span style="color:var(--shiki-token-function)">.filter</span><span style="color:var(--shiki-color-text)">(todo </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">todo</span><span style="color:var(--shiki-color-text)">.id </span><span style="color:var(--shiki-token-keyword)">!==</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'1'</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> [</span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">filteredTodos</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> updatedTodo]</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> }</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// Since the API already gives us the updated information,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// we don't need to revalidate here.</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> revalidate</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">false</span></span> <span class="line"><span style="color:var(--shiki-color-text)">})</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">When combined with <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">optimisticData</code> and <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">rollbackOnError</code>, you’ll get a perfect optimistic UI experience.</p> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400">Avoid Race Conditions<span class="nx-absolute -nx-mt-20" id="avoid-race-conditions"></span><a href="#avoid-race-conditions" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">Both <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code> and <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code> can avoid race conditions between <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWR</code>. For example,</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="tsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="tsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">function</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">Profile</span><span style="color:var(--shiki-color-text)">() {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWR</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> getUser</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> { revalidateInterval</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">3000</span><span style="color:var(--shiki-color-text)"> })</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> { </span><span style="color:var(--shiki-token-constant)">trigger</span><span style="color:var(--shiki-color-text)"> } </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">useSWRMutation</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/user'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> updateUser)</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> <></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> {data </span><span style="color:var(--shiki-token-keyword)">?</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">data</span><span style="color:var(--shiki-color-text)">.username </span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">null</span><span style="color:var(--shiki-color-text)">}</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> <</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">onClick</span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)">{() </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">trigger</span><span style="color:var(--shiki-color-text)">()}>Update User</</span><span style="color:var(--shiki-token-string-expression)">button</span><span style="color:var(--shiki-color-text)">></span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </></span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">The normal <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWR</code> hook might refresh its data any time due to focus, polling, or other conditions. This way the displayed username can be as fresh as possible. However, since we have a mutation there that can happen at the nearly same time of a refetch of <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWR</code>, there could be a race condition that <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">getUser</code> request starts earlier, but takes longer than <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">updateUser</code>.</p> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">Luckily, <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWRMutation</code> handles this for you automatically. After the mutation, it will tell <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">useSWR</code> to ditch the ongoing request and revalidate, so the stale data will never be displayed.</p> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400">Mutate Based on Current Data<span class="nx-absolute -nx-mt-20" id="mutate-based-on-current-data"></span><a href="#mutate-based-on-current-data" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">Sometimes, you want to update a part of your data based on the current data.</p> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">With <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code>, you can pass an async function which will receive the current cached value, if any, and returns an updated document.</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/todos'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">async</span><span style="color:var(--shiki-color-text)"> todos </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// let's update the todo with ID `1` to be completed,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// this API returns the updated data</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">updatedTodo</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">await</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">fetch</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/todos/1'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> {</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> method</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'PATCH'</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> body</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">JSON</span><span style="color:var(--shiki-token-function)">.stringify</span><span style="color:var(--shiki-color-text)">({ completed</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">true</span><span style="color:var(--shiki-color-text)"> })</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> })</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-comment)">// filter the list, and return it with the updated item</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">filteredTodos</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">todos</span><span style="color:var(--shiki-token-function)">.filter</span><span style="color:var(--shiki-color-text)">(todo </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">todo</span><span style="color:var(--shiki-color-text)">.id </span><span style="color:var(--shiki-token-keyword)">!==</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'1'</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">return</span><span style="color:var(--shiki-color-text)"> [</span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">filteredTodos</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> updatedTodo]</span></span> <span class="line"><span style="color:var(--shiki-token-comment)">// Since the API already gives us the updated information,</span></span> <span class="line"><span style="color:var(--shiki-token-comment)">// we don't need to revalidate here.</span></span> <span class="line"><span style="color:var(--shiki-color-text)">}</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> { revalidate</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">false</span><span style="color:var(--shiki-color-text)"> })</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <h2 class="nx-font-semibold nx-tracking-tight nx-text-slate-900 dark:nx-text-slate-100 nx-mt-10 nx-border-b nx-pb-1 nx-text-3xl nx-border-neutral-200/70 contrast-more:nx-border-neutral-400 dark:nx-border-primary-100/10 contrast-more:dark:nx-border-neutral-400">Mutate Multiple Items<span class="nx-absolute -nx-mt-20" id="mutate-multiple-items"></span><a href="#mutate-multiple-items" class="subheading-anchor" aria-label="Permalink for this section"></a></h2> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">The global <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">mutate</code> API accepts a filter function, which accepts <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">key</code> as the argument and returns which keys to revalidate. The filter function is applied to all the existing cache keys:</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">import</span><span style="color:var(--shiki-color-text)"> { mutate } </span><span style="color:var(--shiki-token-keyword)">from</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'swr'</span></span> <span class="line"><span style="color:var(--shiki-token-comment)">// Or from the hook if you customized the cache provider:</span></span> <span class="line"><span style="color:var(--shiki-token-comment)">// { mutate } = useSWRConfig()</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> key </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">typeof</span><span style="color:var(--shiki-color-text)"> key </span><span style="color:var(--shiki-token-keyword)">===</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'string'</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">&&</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">key</span><span style="color:var(--shiki-token-function)">.startsWith</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api/item?id='</span><span style="color:var(--shiki-color-text)">)</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">undefined</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> { revalidate</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">true</span><span style="color:var(--shiki-color-text)"> }</span></span> <span class="line"><span style="color:var(--shiki-color-text)">)</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">This also works with any key type like an array. The mutation matches all keys, of which the first element is <code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr">'item'</code>.</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-function)">useSWR</span><span style="color:var(--shiki-color-text)">([</span><span style="color:var(--shiki-token-string-expression)">'item'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">123</span><span style="color:var(--shiki-color-text)">]</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"><span style="color:var(--shiki-token-function)">useSWR</span><span style="color:var(--shiki-color-text)">([</span><span style="color:var(--shiki-token-string-expression)">'item'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">124</span><span style="color:var(--shiki-color-text)">]</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"><span style="color:var(--shiki-token-function)">useSWR</span><span style="color:var(--shiki-color-text)">([</span><span style="color:var(--shiki-token-string-expression)">'item'</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">125</span><span style="color:var(--shiki-color-text)">]</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">...</span><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> key </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">Array</span><span style="color:var(--shiki-token-function)">.isArray</span><span style="color:var(--shiki-color-text)">(key) </span><span style="color:var(--shiki-token-keyword)">&&</span><span style="color:var(--shiki-color-text)"> key[</span><span style="color:var(--shiki-token-constant)">0</span><span style="color:var(--shiki-color-text)">] </span><span style="color:var(--shiki-token-keyword)">===</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'item'</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">undefined</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> { revalidate</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">false</span><span style="color:var(--shiki-color-text)"> }</span></span> <span class="line"><span style="color:var(--shiki-color-text)">)</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">The filter function is applied to all existing cache keys, so you should not assume the shape of keys when using multiple shapes of keys.</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="jsx" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="jsx" data-theme="default"><span class="line"><span style="color:var(--shiki-token-comment)">// ✅ matching array key</span></span> <span class="line"><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">((key) </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> key[</span><span style="color:var(--shiki-token-constant)">0</span><span style="color:var(--shiki-color-text)">]</span><span style="color:var(--shiki-token-function)">.startsWith</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api'</span><span style="color:var(--shiki-color-text)">)</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> data)</span></span> <span class="line"><span style="color:var(--shiki-token-comment)">// ✅ matching string key</span></span> <span class="line"><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">((key) </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">typeof</span><span style="color:var(--shiki-color-text)"> key </span><span style="color:var(--shiki-token-keyword)">===</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-string-expression)">'string'</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">&&</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">key</span><span style="color:var(--shiki-token-function)">.startsWith</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-string-expression)">'/api'</span><span style="color:var(--shiki-color-text)">)</span><span style="color:var(--shiki-token-punctuation)">,</span><span style="color:var(--shiki-color-text)"> data)</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-comment)">// ❌ ERROR: mutate uncertain keys (array or string)</span></span> <span class="line"><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">((key</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">any</span><span style="color:var(--shiki-color-text)">) </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-token-string-expression)"> /\/api/</span><span style="color:var(--shiki-token-function)">.test</span><span style="color:var(--shiki-color-text)">(</span><span style="color:var(--shiki-token-constant)">key</span><span style="color:var(--shiki-token-function)">.toString</span><span style="color:var(--shiki-color-text)">()))</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 4-4s-1.79-4-4-4z"></path></svg></button><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50" title="Copy code" tabindex="0"><svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg" stroke="currentColor" class="nextra-copy-icon nx-pointer-events-none nx-h-4 nx-w-4"><rect x="9" y="9" width="13" height="13" rx="2" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></rect><path d="M5 15H4C2.89543 15 2 14.1046 2 13V4C2 2.89543 2.89543 2 4 2H13C14.1046 2 15 2.89543 15 4V5" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"></path></svg></button></div></div> <p class="nx-mt-6 nx-leading-7 first:nx-mt-0">You can use the filter function to clear all cache data, which is useful when logging out:</p> <div class="nextra-code-block nx-relative nx-mt-6 first:nx-mt-0"><pre class="nx-bg-primary-700/5 nx-mb-4 nx-overflow-x-auto nx-rounded-xl nx-subpixel-antialiased dark:nx-bg-primary-300/10 nx-text-[.9em] contrast-more:nx-border contrast-more:nx-border-primary-900/20 contrast-more:nx-contrast-150 contrast-more:dark:nx-border-primary-100/40 nx-py-4" data-language="js" data-theme="default"><code class="nx-border-black nx-border-opacity-[0.04] nx-bg-opacity-[0.03] nx-bg-black nx-break-words nx-rounded-md nx-border nx-py-0.5 nx-px-[.25em] nx-text-[.9em] dark:nx-border-white/10 dark:nx-bg-white/10" dir="ltr" data-language="js" data-theme="default"><span class="line"><span style="color:var(--shiki-token-keyword)">const</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">clearCache</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-keyword)">=</span><span style="color:var(--shiki-color-text)"> () </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-function)">mutate</span><span style="color:var(--shiki-color-text)">(</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> () </span><span style="color:var(--shiki-token-keyword)">=></span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">true</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">undefined</span><span style="color:var(--shiki-token-punctuation)">,</span></span> <span class="line"><span style="color:var(--shiki-color-text)"> { revalidate</span><span style="color:var(--shiki-token-keyword)">:</span><span style="color:var(--shiki-color-text)"> </span><span style="color:var(--shiki-token-constant)">false</span><span style="color:var(--shiki-color-text)"> }</span></span> <span class="line"><span style="color:var(--shiki-color-text)">)</span></span> <span class="line"> </span> <span class="line"><span style="color:var(--shiki-token-comment)">// ...clear cache on logout</span></span> <span class="line"><span style="color:var(--shiki-token-function)">clearCache</span><span style="color:var(--shiki-color-text)">()</span></span></code></pre><div class="nx-opacity-0 nx-transition [div:hover>&]:nx-opacity-100 focus-within:nx-opacity-100 nx-flex nx-gap-1 nx-absolute nx-m-[11px] nx-right-0 nx-top-0"><button class="nextra-button nx-transition-all active:nx-opacity-50 nx-bg-primary-700/5 nx-border nx-border-black/5 nx-text-gray-600 hover:nx-text-gray-900 nx-rounded-md nx-p-1.5 dark:nx-bg-primary-300/10 dark:nx-border-white/10 dark:nx-text-gray-400 dark:hover:nx-text-gray-50 md:nx-hidden" title="Toggle word wrap"><svg viewBox="0 0 24 24" width="24" height="24" class="nx-pointer-events-none nx-h-4 nx-w-4"><path fill="currentColor" d="M4 19h6v-2H4v2zM20 5H4v2h16V5zm-3 6H4v2h13.25c1.1 0 2 .9 2 2s-.9 2-2 2H15v-2l-3 3l3 3v-2h2c2.21 0 4-1.79 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