--- title: 'Creating a Supabase client for SSR' subtitle: 'Configure your Supabase client to use cookies' --- To use Server-Side Rendering (SSR) with Supabase, you need to configure your Supabase client to use cookies. The `@supabase/ssr` package helps you do this for JavaScript/TypeScript applications. ## Install Install the `@supabase/supabase-js` and `@supabase/ssr` helper packages: ```bash npm install @supabase/supabase-js @supabase/ssr ``` ```bash yarn add @supabase/supabase-js @supabase/ssr ``` ```bash pnpm add @supabase/supabase-js @supabase/ssr ``` ## Set environment variables Create a `.env.local` file in the project root directory. In the file, set the project's Supabase URL and Key: <$Partial path="api_settings_steps.mdx" variables={{ "framework": "nextjs", "tab": "frameworks" }} /> ```bash .env.local NEXT_PUBLIC_SUPABASE_URL=supabase_project_url NEXT_PUBLIC_SUPABASE_PUBLISHABLE_KEY=supabase_publishable_key ``` ```bash .env.local PUBLIC_SUPABASE_URL=supabase_project_url PUBLIC_SUPABASE_PUBLISHABLE_KEY=supabase_publishable_key ``` ```bash .env PUBLIC_SUPABASE_URL=supabase_project_url PUBLIC_SUPABASE_PUBLISHABLE_KEY=supabase_publishable_key ``` ```bash .env SUPABASE_URL=supabase_project_url SUPABASE_PUBLISHABLE_KEY=supabase_publishable_key ``` ```bash .env SUPABASE_URL=supabase_project_url SUPABASE_PUBLISHABLE_KEY=supabase_publishable_key ``` ```bash .env SUPABASE_URL=supabase_project_url SUPABASE_PUBLISHABLE_KEY=supabase_publishable_key ``` Install [dotenv](https://www.npmjs.com/package/dotenv): ```bash npm i dotenv ``` And initialize it: ```bash npm install dotenv ``` ```bash yarn add dotenv ``` ```bash pnpm add dotenv ``` ```bash .env SUPABASE_URL=supabase_project_url SUPABASE_PUBLISHABLE_KEY=supabase_publishable_key ``` ## Create a client {/* TODO: Can this be consolidated? */} You need setup code to configure a Supabase client to use cookies. Once you have the utility code, you can use the `createClient` utility functions to get a properly configured Supabase client. Use the browser client in code that runs on the browser, and the server client in code that runs on the server. ### Write utility functions to create Supabase clients To access Supabase from a Next.js app, you need 2 types of Supabase clients: 1. **Client Component client** - To access Supabase from Client Components, which run in the browser. 2. **Server Component client** - To access Supabase from Server Components, Server Actions, and Route Handlers, which run only on the server. Since Next.js Server Components can't write cookies, you need a [Proxy](https://nextjs.org/docs/app/getting-started/proxy) to refresh expired Auth tokens and store them. The Proxy is responsible for: 1. Refreshing the Auth token by calling `supabase.auth.getClaims()`. 2. Passing the refreshed Auth token to Server Components, so they don't attempt to refresh the same token themselves. This is accomplished with `request.cookies.set`. 3. Passing the refreshed Auth token to the browser, so it replaces the old token. This is accomplished with `response.cookies.set`. What does the `cookies` object do?} id="utility-cookies" > The cookies object lets the Supabase client know how to access the cookies, so it can read and write the user session data. To make `@supabase/ssr` framework-agnostic, the cookies methods aren't hard-coded. These utility functions adapt `@supabase/ssr`'s cookie handling for Next.js. The `set` and `remove` methods for the server client need error handlers, because Next.js throws an error if cookies are set from Server Components. You can safely ignore this error because you'll set up Proxy in the next step to write refreshed cookies to storage. The cookie is named `sb--auth-token` by default. Do I need to create a new client for every route?} id="client-deduplication" > Yes! Creating a Supabase client is lightweight. - On the server, it basically configures a `fetch` call. You need to reconfigure the fetch call anew for every request to your server, because you need the cookies from the request. - On the client, `createBrowserClient` already uses a singleton pattern, so you only ever create one instance, no matter how many times you call your `createClient` function. Create a `lib/supabase` folder at the root of your project, or inside the `./src` folder if you are using one, with a file for each type of client. Then copy the lib utility functions for each client type.
<$CodeTabs> <$CodeSample path="/auth/nextjs/lib/supabase/client.ts" meta="name=lib/supabase/client.ts" language="typescript" /> <$CodeSample path="/auth/nextjs/lib/supabase/server.ts" meta="name=lib/supabase/server.ts" language="typescript" />
### Hook up proxy The code adds a [matcher](https://nextjs.org/docs/app/api-reference/file-conventions/proxy#matcher) so the Proxy doesn't run on routes that don't access Supabase. Be careful when protecting pages. The server gets the user session from the cookies, which can be spoofed by anyone. Always use `supabase.auth.getClaims()` to protect pages and user data. _Never_ trust `supabase.auth.getSession()` inside server code such as Proxy. It isn't guaranteed to revalidate the Auth token. It's safe to trust `getClaims()` because it validates the JWT signature against the project's published public keys every time.
<$CodeTabs> <$CodeSample path="/auth/nextjs/proxy.ts" meta="name=proxy.ts" language="typescript" /> <$CodeSample path="/auth/nextjs/lib/supabase/proxy.ts" meta="name=lib/supabase/proxy.ts" language="typescript" />
## Congratulations You're done! To recap, you've successfully: - Called Supabase from a Server Action. - Called Supabase from a Server Component. - Set up a Supabase client utility to call Supabase from a Client Component. You can use this if you need to call Supabase from a Client Component, for example to set up a realtime subscription. - Set up Proxy to automatically refresh the Supabase Auth session. You can now use any Supabase features from your client or server code!
### Set up server-side hooks Set up server-side hooks in `src/hooks.server.ts`. The hooks: - Create a request-specific Supabase client, using the user credentials from the request cookie. This client is used for server-only code. - Check user authentication. - Guard protected pages. <$CodeSample path="/auth/sveltekit/src/hooks.server.ts" meta="name=src/hooks.server.ts" language="typescript" /> To prevent TypeScript errors, add type definitions for the new event.locals properties. <$CodeSample path="/auth/sveltekit/src/app.d.ts" meta="name=src/app.d.ts" language="typescript" /> ### Create a Supabase client in your root layout Create a Supabase client in your root `+layout.ts`. This client can be used to access Supabase from the client or the server. In order to get access to the Auth token on the server, use a `+layout.server.ts` file to pass in the session from event.locals. Page components can access the Supabase client from the `data` object using the `load` function. <$CodeTabs> <$CodeSample path="/auth/sveltekit/src/routes/+layout.ts" meta="name=src/routes/+layout.ts" language="typescript" /> <$CodeSample path="/auth/sveltekit/src/routes/+layout.server.ts" meta="name=src/routes/+layout.server.ts" language="typescript" /> ## Congratulations You're done! To recap, you've successfully: - Set up server-side hooks to create a request-specific Supabase client and guard protected pages. - Created a Supabase client in your root layout to use on both the client and server. You can now use any Supabase features from your client or server code! By default, Astro apps are static. This means the requests for data happen at build time, rather than when the user requests a page. At build time, there is no user, session or cookies. Therefore, we need to configure Astro for Server-side Rendering (SSR) if you want data to be fetched dynamically per request. ```js astro.config.mjs import { defineConfig } from 'astro/config' export default defineConfig({ output: 'server', }) ``` ```ts index.astro --- import { createServerClient, parseCookieHeader } from "@supabase/ssr"; const supabase = createServerClient( import.meta.env.PUBLIC_SUPABASE_URL, import.meta.env.PUBLIC_SUPABASE_PUBLISHABLE_KEY, { cookies: { getAll() { return parseCookieHeader(Astro.request.headers.get('Cookie') ?? '') }, setAll(cookiesToSet) { cookiesToSet.forEach(({ name, value }) => Astro.cookies.set(name, value)) }, }, } ); --- ``` ```html index.astro ``` ```ts route.ts import { createServerClient, parseCookieHeader } from "@supabase/ssr"; import type { APIContext } from "astro"; export async function GET(context: APIContext) { const supabase = createServerClient( import.meta.env.PUBLIC_SUPABASE_URL, import.meta.env.PUBLIC_SUPABASE_PUBLISHABLE_KEY, { cookies: { getAll() { return parseCookieHeader(context.request.headers.get('Cookie') ?? '') }, setAll(cookiesToSet) { cookiesToSet.forEach(({ name, value }) => context.cookies.set(name, value)) }, }, } ); return ... } ``` ```ts middleware.ts import { createServerClient, parseCookieHeader } from '@supabase/ssr' import { defineMiddleware } from 'astro:middleware' export const onRequest = defineMiddleware(async (context, next) => { const supabase = createServerClient( import.meta.env.PUBLIC_SUPABASE_URL, import.meta.env.PUBLIC_SUPABASE_PUBLISHABLE_KEY, { cookies: { getAll() { return parseCookieHeader(context.request.headers.get('Cookie') ?? '') }, setAll(cookiesToSet) { cookiesToSet.forEach(({ name, value }) => context.cookies.set(name, value)) }, }, } ) return next() }) ``` ## Congratulations You can now use any Supabase features from your client or server code! ```ts _index.tsx import { type LoaderFunctionArgs } from '@remix-run/node' import { createServerClient, parseCookieHeader, serializeCookieHeader } from '@supabase/ssr' export async function loader({ request }: LoaderFunctionArgs) { const headers = new Headers() const supabase = createServerClient( process.env.SUPABASE_URL!, process.env.SUPABASE_PUBLISHABLE_KEY!, { cookies: { getAll() { return parseCookieHeader(request.headers.get('Cookie') ?? '') }, setAll(cookiesToSet) { cookiesToSet.forEach(({ name, value }) => headers.append('Set-Cookie', serializeCookieHeader(name, value)) ) }, }, } ) return new Response('...', { headers, }) } ``` ```ts _index.tsx import { type ActionFunctionArgs } from '@remix-run/node' import { createServerClient, parseCookieHeader, serializeCookieHeader } from '@supabase/ssr' export async function action({ request }: ActionFunctionArgs) { const headers = new Headers() const supabase = createServerClient( process.env.SUPABASE_URL!, process.env.SUPABASE_PUBLISHABLE_KEY!, { cookies: { getAll() { return parseCookieHeader(request.headers.get('Cookie') ?? '') }, setAll(cookiesToSet) { cookiesToSet.forEach(({ name, value }) => headers.append('Set-Cookie', serializeCookieHeader(name, value)) ) }, }, } ) return new Response('...', { headers, }) } ``` ```ts _index.tsx import { type LoaderFunctionArgs } from "@remix-run/node"; import { useLoaderData } from "@remix-run/react"; import { createBrowserClient } from "@supabase/ssr"; export async function loader({}: LoaderFunctionArgs) { return { env: { SUPABASE_URL: process.env.SUPABASE_URL!, SUPABASE_PUBLISHABLE_KEY: process.env.SUPABASE_PUBLISHABLE_KEY!, }, }; } export default function Index() { const { env } = useLoaderData(); const supabase = createBrowserClient(env.SUPABASE_URL, env.SUPABASE_PUBLISHABLE_KEY); return ... } ``` ## Congratulations You can now use any Supabase features from your client or server code! ```ts _index.tsx import { LoaderFunctionArgs } from 'react-router' import { createServerClient, parseCookieHeader, serializeCookieHeader } from '@supabase/ssr' export async function loader({ request }: LoaderFunctionArgs) { const headers = new Headers() const supabase = createServerClient(process.env.SUPABASE_URL!, process.env.SUPABASE_ANON_KEY!, { cookies: { getAll() { return parseCookieHeader(request.headers.get('Cookie') ?? '') }, setAll(cookiesToSet) { cookiesToSet.forEach(({ name, value }) => headers.append('Set-Cookie', serializeCookieHeader(name, value)) ) }, }, }) return new Response('...', { headers, }) } ``` ```ts _index.tsx import { type ActionFunctionArgs } from '@react-router' import { createServerClient, parseCookieHeader, serializeCookieHeader } from '@supabase/ssr' export async function action({ request }: ActionFunctionArgs) { const headers = new Headers() const supabase = createServerClient(process.env.SUPABASE_URL!, process.env.SUPABASE_ANON_KEY!, { cookies: { getAll() { return parseCookieHeader(request.headers.get('Cookie') ?? '') }, setAll(cookiesToSet) { cookiesToSet.forEach(({ name, value }) => headers.append('Set-Cookie', serializeCookieHeader(name, value)) ) }, }, }) return new Response('...', { headers, }) } ``` ```ts _index.tsx import { type LoaderFunctionArgs } from "react-router"; import { useLoaderData } from "react-router"; import { createBrowserClient } from "@supabase/ssr"; export async function loader({}: LoaderFunctionArgs) { return { env: { SUPABASE_URL: process.env.SUPABASE_URL!, SUPABASE_ANON_KEY: process.env.SUPABASE_ANON_KEY!, }, }; } export default function Index() { const { env } = useLoaderData(); const supabase = createBrowserClient(env.SUPABASE_URL, env.SUPABASE_ANON_KEY); return ... } ``` ## Congratulations You can now use any Supabase features from your client or server code! ```ts lib/supabase.js const { createServerClient, parseCookieHeader, serializeCookieHeader } = require('@supabase/ssr') exports.createClient = (context) => { return createServerClient(process.env.SUPABASE_URL, process.env.SUPABASE_PUBLISHABLE_KEY, { cookies: { getAll() { return parseCookieHeader(context.req.headers.cookie ?? '') }, setAll(cookiesToSet) { cookiesToSet.forEach(({ name, value }) => context.res.appendHeader('Set-Cookie', serializeCookieHeader(name, value)) ) }, }, }) } ``` ```ts app.js const express = require("express") const dotenv = require("dotenv") const { createClient } = require("./lib/supabase") const app = express() app.post("/hello-world", async function (req, res, next) { const { email, emailConfirm } = req.body ... const supabase = createClient({ req, res }) }) ``` ## Congratulations You can now use any Supabase features from your client or server code! Create a Hono middleware that creates a Supabase client. <$CodeSample path="/auth/hono/src/middleware/auth.middleware.ts" meta="name=src/middleware/auth.middleware.ts" language="typescript" /> You can now use this middleware in your Hono application to create a server Supabase client that can be used to make authenticated requests. <$CodeSample path="/auth/hono/src/index.tsx" meta="name=src/index.tsx" language="typescript" />
## Next steps - Implement [Authentication using Email and Password](/docs/guides/auth/server-side/email-based-auth-with-pkce-flow-for-ssr) - Implement [Authentication using OAuth](/docs/guides/auth/server-side/oauth-with-pkce-flow-for-ssr) - [Learn more about SSR](/docs/guides/auth/server-side-rendering)