CORS (Cross-Origin Resource Sharing) support for Invoking from the browser

To invoke edge functions from the browser, you need to handle CORS Preflight requests.

See the example on GitHub.

Recommended setup#

For @supabase/supabase-js v2.95.0 and later: Import CORS headers directly from the SDK to ensure they stay synchronized with any new headers added to the client libraries.

Import corsHeaders from @supabase/supabase-js/cors to automatically get all required headers:

1import { corsHeaders } from '@supabase/supabase-js/cors'23console.log(`Function "browser-with-cors" up and running!`)45Deno.serve(async (req) => {6  // This is needed if you're planning to invoke your function from a browser.7  if (req.method === 'OPTIONS') {8    return new Response('ok', { headers: corsHeaders })9  }1011  try {12    const { name } = await req.json()13    const data = {14      message: `Hello ${name}!`,15    }1617    return new Response(JSON.stringify(data), {18      headers: { ...corsHeaders, 'Content-Type': 'application/json' },19      status: 200,20    })21  } catch (error) {22    return new Response(JSON.stringify({ error: error.message }), {23      headers: { ...corsHeaders, 'Content-Type': 'application/json' },24      status: 400,25    })26  }27})

This approach ensures that when new headers are added to the Supabase SDK, your Edge Functions automatically include them, preventing CORS errors.

For versions before 2.95.0#

If you're using @supabase/supabase-js before v2.95.0, you'll need to hardcode the CORS headers. Add a cors.ts file within a _shared folder:

1export const corsHeaders = {2  'Access-Control-Allow-Origin': '*',3  'Access-Control-Allow-Headers': 'authorization, x-client-info, apikey, content-type',4}

Then import it in your function:

1import { corsHeaders } from '../_shared/cors.ts'23// ... rest of your function code