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Auth

Use Supabase Auth with Astro

Learn how to configure Supabase Auth for Astro with server-side rendering.

1

Create a new Supabase project

Head over to database.new and create a new Supabase project.

Your new database has a table for storing your users. You can see that this table is currently empty by running some SQL in the SQL Editor.

SQL_EDITOR
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select * from auth.users;
2

Create an Astro app

Create a new Astro app using the npm create command.

Terminal
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npm create astro@latest my-app
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cd my-app
3

Install Supabase libraries and Node adapter

Install the @supabase/supabase-js client library, @supabase/ssr for server-side auth, and the @astrojs/node adapter to enable server-side rendering.

Terminal
1
npm install @supabase/supabase-js @supabase/ssr @astrojs/node
4

Configure Astro for SSR

Update your astro.config.mjs to enable server-side rendering with the Node adapter.

astro.config.mjs
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import { defineConfig } from "astro/config";
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import node from "@astrojs/node";
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export default defineConfig({
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  output: "server",
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  adapter: node({
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    mode: "standalone",
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  }),
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});
5

Declare Supabase Environment Variables

Create a .env.local file and populate with your Supabase connection variables:

Project URL
Publishable key
.env.local
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PUBLIC_SUPABASE_URL=your-project-url
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PUBLIC_SUPABASE_PUBLISHABLE_KEY=sb_publishable_key

Get API details#

To interact with data in database tables, you use the client libraries that wrap the auto-generated Data API endpoints, authenticating using the Project URL and key from the project Connect dialog.

Project URL
Publishable key
6

Create a Supabase client helper

Create a utility file to initialize the Supabase client with SSR support:

src/lib/supabase.ts
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import { createServerClient, parseCookieHeader } from "@supabase/ssr";
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import type { AstroCookies } from "astro";
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const supabaseUrl = import.meta.env.PUBLIC_SUPABASE_URL
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const supabasePublishableKey = import.meta.env.PUBLIC_SUPABASE_PUBLISHABLE_KEY
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export function createClient({
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  request,
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  cookies,
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}: {
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  request: Request;
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  cookies: AstroCookies;
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}) {
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  return createServerClient(
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    supabaseUrl,
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    supabasePublishableKey,
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    {
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      cookies: {
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        getAll() {
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          return parseCookieHeader(
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            request.headers.get("Cookie") ?? ""
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          );
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        },
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        setAll(cookiesToSet) {
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          cookiesToSet.forEach(({ name, value, options }) =>
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            cookies.set(name, value, options)
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          );
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        },
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      },
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    }
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  );
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}
7

Create authentication actions

Create a new file at src/actions/index.ts to define server-side authentication actions for signing up, signing in, and signing out:

src/actions/index.ts
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import { defineAction } from "astro:actions";
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import { z } from "astro/zod";
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import { createClient } from "../lib/supabase";
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export const server = {
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  signUp: defineAction({
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    accept: "form",
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    input: z.object({
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      email: z.string().email(),
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      password: z.string().min(6),
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    }),
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    handler: async (input, context) => {
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      try {
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        const supabase = createClient({
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          request: context.request,
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          cookies: context.cookies,
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        });
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        const { error } = await supabase.auth.signUp({
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          email: input.email,
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          password: input.password,
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          options: {
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            emailRedirectTo: "http://localhost:4321/auth/callback",
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          },
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        });
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        if (error) {
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          return {
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            success: false,
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            message: error.message,
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          };
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        }
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        return {
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          success: true,
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          message: "Check your email to confirm your account",
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        };
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      } catch (err) {
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        return {
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          success: false,
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          message: "Unexpected error",
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        };
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      }
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    },
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  }),
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  signIn: defineAction({
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    accept: "form",
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    input: z.object({
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      email: z.string().email(),
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      password: z.string(),
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    }),
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    handler: async (input, context) => {
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      try {
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        const supabase = createClient({
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          request: context.request,
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          cookies: context.cookies,
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        });
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        const { error } = await supabase.auth.signInWithPassword({
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          email: input.email,
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          password: input.password,
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        });
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        if (error) {
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          return {
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            success: false,
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            message: error.message,
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          };
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        }
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        return {
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          success: true,
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          message: "Signed in successfully",
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        };
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      } catch (err) {
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        return {
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          success: false,
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          message: "Unexpected error",
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        };
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      }
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    },
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  }),
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  signOut: defineAction({
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    handler: async (_, context) => {
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      try {
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        const supabase = createClient({
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          request: context.request,
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          cookies: context.cookies,
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        });
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        await supabase.auth.signOut();
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        return {
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          success: true,
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        };
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      } catch (err) {
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        return {
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          success: false,
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          message: "Failed to sign out",
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        };
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      }
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    },
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  }),
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};
8

Customize email template

Before users can confirm their email, update the Supabase email template to send the token hash to your callback URL.

In your Supabase project dashboard:

  • Go to Auth > Email Templates
  • Select the Confirm signup template
  • Change {{ .ConfirmationURL }} to {{ .SiteURL }}/auth/callback?token_hash={{ .TokenHash }}&type=email.
  • Change your Site URL to http://localhost:4321
Email\
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{{ .SiteURL }}/auth/callback?token_hash={{ .TokenHash }}&type=email
9

Create an auth callback page

Create a new file at src/pages/auth/callback.astro to handle the email confirmation callback. Extract the token from the URL and verify it with Supabase:

src/pages/auth/callback.astro
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---
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import { createClient } from "../../lib/supabase";
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import type { EmailOtpType } from "@supabase/supabase-js";
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const supabase = createClient({
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  request: Astro.request,
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  cookies: Astro.cookies,
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});
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const requestUrl = new URL(Astro.request.url);
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const token_hash = requestUrl.searchParams.get('token_hash');
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const type = requestUrl.searchParams.get('type') as EmailOtpType | null;
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if (token_hash && type) {
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  const { error } = await supabase.auth.verifyOtp({
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    token_hash,
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    type,
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  });
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  if (!error) {
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    return Astro.redirect("/dashboard");
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  }
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}
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return Astro.redirect("/auth/signin");
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---
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<html>
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  <head>
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    <title>Email Confirmation</title>
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  </head>
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  <body>
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    <p>Confirming your email...</p>
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  </body>
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</html>
10

Create a sign-up page

Create a new file at src/pages/auth/signup.astro with a sign-up form. Use a client-side event listener to handle form submission:

src/pages/auth/signup.astro
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---
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import { createClient } from "../../lib/supabase";
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const supabase = createClient({
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  request: Astro.request,
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  cookies: Astro.cookies,
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});
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const { data } = await supabase.auth.getUser();
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if (data?.user) {
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  return Astro.redirect("/dashboard");
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}
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---
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<html>
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  <head>
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    <title>Sign Up</title>
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  </head>
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  <body>
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    <h1>Sign Up</h1>
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    <div id="message"></div>
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    <form id="signup-form">
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      <div>
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        <label for="email">Email</label>
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        <input
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          id="email"
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          type="email"
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          name="email"
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          placeholder="your@email.com"
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          required
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        />
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      </div>
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      <div>
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        <label for="password">Password</label>
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        <input
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          id="password"
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          type="password"
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          name="password"
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          placeholder="At least 6 characters"
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          required
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        />
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      </div>
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      <button type="submit" id="signup-btn">Sign Up</button>
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    </form>
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    <p>
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      Already have an account? <a href="/auth/signin">Sign in</a>
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    </p>
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  </body>
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</html>
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<script>
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  import { actions } from "astro:actions";
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  const form = document.querySelector("#signup-form") as HTMLFormElement;
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  const btn = document.getElementById("signup-btn") as HTMLButtonElement;
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  const messageEl = document.getElementById("message") as HTMLDivElement;
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  form?.addEventListener("submit", async (e) => {
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    e.preventDefault();
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    btn.disabled = true;
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    btn.textContent = "Signing up...";
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    messageEl.textContent = "";
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    try {
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      const formData = new FormData(form);
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      const result = await actions.signUp(formData);
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      if (!result.data?.success) {
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        btn.disabled = false;
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        btn.textContent = "Sign Up";
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        messageEl.textContent = result.data?.message || "Sign up failed";
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        messageEl.style.color = "red";
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        return;
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      }
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      messageEl.textContent = result.data.message;
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      messageEl.style.color = "green";
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      btn.textContent = "Sign Up";
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    } catch (error) {
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      btn.disabled = false;
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      btn.textContent = "Sign Up";
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      messageEl.textContent = "An error occurred. Please try again.";
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      messageEl.style.color = "red";
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      console.error(error);
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    }
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  });
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</script>
11

Create a sign-in page

Create a new file at src/pages/auth/signin.astro with a sign-in form. Use a client-side event listener to handle form submission:

src/pages/auth/signin.astro
1
---
2
import { createClient } from "../../lib/supabase";
3
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const supabase = createClient({
5
  request: Astro.request,
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  cookies: Astro.cookies,
7
});
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const { data } = await supabase.auth.getUser();
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if (data?.user) {
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  return Astro.redirect("/dashboard");
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}
14
---
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<html>
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  <head>
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    <title>Sign In</title>
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  </head>
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  <body>
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    <h1>Sign In</h1>
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    <div id="message"></div>
24
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    <form id="signin-form">
26
      <div>
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        <label for="email">Email</label>
28
        <input
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          id="email"
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          type="email"
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          name="email"
32
          placeholder="your@email.com"
33
          required
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        />
35
      </div>
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      <div>
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        <label for="password">Password</label>
38
        <input
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          id="password"
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          type="password"
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          name="password"
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          placeholder="Your password"
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          required
44
        />
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      </div>
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      <button type="submit" id="signin-btn">Sign In</button>
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    </form>
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    <p>
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      Don't have an account? <a href="/auth/signup">Sign up</a>
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    </p>
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  </body>
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</html>
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<script>
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  import { actions } from "astro:actions";
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  const form = document.querySelector("#signin-form") as HTMLFormElement;
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  const btn = document.getElementById("signin-btn") as HTMLButtonElement;
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  const messageEl = document.getElementById("message") as HTMLDivElement;
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  form?.addEventListener("submit", async (e) => {
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    e.preventDefault();
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    btn.disabled = true;
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    btn.textContent = "Signing in...";
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    messageEl.textContent = "";
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    try {
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      const formData = new FormData(form);
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      const result = await actions.signIn(formData);
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      if (!result.data?.success) {
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        btn.disabled = false;
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        btn.textContent = "Sign In";
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        messageEl.textContent = result.data?.message || "Sign in failed";
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        messageEl.style.color = "red";
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        return;
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      }
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      // Redirect to dashboard on successful sign in
80
      window.location.href = "/dashboard";
81
    } catch (error) {
82
      btn.disabled = false;
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      btn.textContent = "Sign In";
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      messageEl.textContent = "An error occurred. Please try again.";
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      messageEl.style.color = "red";
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      console.error(error);
87
    }
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  });
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</script>
12

Create a dashboard page

Create a new file at src/pages/dashboard.astro to display the authenticated user's information. Use a client-side event listener for the sign-out button:

src/pages/dashboard.astro
1
---
2
import { createClient } from "../lib/supabase";
3
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const supabase = createClient({
5
  request: Astro.request,
6
  cookies: Astro.cookies,
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});
8
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const { data } = await supabase.auth.getUser();
10
const user = data?.user;
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12
if (!user) {
13
  return Astro.redirect("/auth/signin");
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}
15
---
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<html>
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  <head>
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    <title>Dashboard</title>
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  </head>
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  <body>
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    <h1>Welcome!</h1>
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    <p>Email: {user.email}</p>
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    <p>User ID: {user.id}</p>
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    <button id="signout-btn">Sign Out</button>
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  </body>
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</html>
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<script>
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  import { actions } from "astro:actions";
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  const btn = document.getElementById("signout-btn") as HTMLButtonElement;
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  btn?.addEventListener("click", async (e) => {
36
    e.preventDefault();
37
    btn.disabled = true;
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    btn.textContent = "Signing out...";
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40
    try {
41
      const result = await actions.signOut();
42
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      if (!result.data?.success) {
44
        btn.disabled = false;
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        btn.textContent = "Sign Out";
46
        alert("Failed to sign out");
47
        return;
48
      }
49
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      // Redirect to signin page
51
      window.location.href = "/auth/signin";
52
    } catch (error) {
53
      btn.disabled = false;
54
      btn.textContent = "Sign Out";
55
      console.error(error);
56
    }
57
  });
58
</script>
13

Start the app

Start the development server, then navigate to http://localhost:4321/auth/signup to test the authentication.

Terminal
1
npm run dev

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