How to Debug Supabase Edge Functions

1# Start local Edge Function server
2supabase functions serve
3
4# The function is available at:
5# http://localhost:54321/functions/v1/your-function-name
6
7# Test with curl
8curl -i --location --request POST \
9  'http://localhost:54321/functions/v1/hello-world' \
10  --header 'Authorization: Bearer YOUR_ANON_KEY' \
11  --header 'Content-Type: application/json' \
12  --data '{"name": "test"}'

1// supabase/functions/process-data/index.ts
2import { corsHeaders } from '../_shared/cors.ts'
3
4Deno.serve(async (req) => {
5  // Handle CORS preflight
6  if (req.method === 'OPTIONS') {
7    return new Response('ok', { headers: corsHeaders })
8  }
9
10  try {
11    const body = await req.json()
12    console.log('Request body:', JSON.stringify(body))
13
14    if (!body.id) {
15      return new Response(
16        JSON.stringify({ error: 'Missing required field: id' }),
17        { status: 400, headers: { ...corsHeaders, 'Content-Type': 'application/json' } }
18      )
19    }
20
21    // Your logic here...
22    const result = { success: true, id: body.id }
23    console.log('Response:', JSON.stringify(result))
24
25    return new Response(
26      JSON.stringify(result),
27      { status: 200, headers: { ...corsHeaders, 'Content-Type': 'application/json' } }
28    )
29  } catch (error) {
30    console.error('Function error:', error.message, error.stack)
31    return new Response(
32      JSON.stringify({ error: 'Internal server error', details: error.message }),
33      { status: 500, headers: { ...corsHeaders, 'Content-Type': 'application/json' } }
34    )
35  }
36})

1# Stream logs for a specific function
2supabase functions logs hello-world
3
4# Stream logs for all functions
5supabase functions logs
6
7# View logs from the Dashboard:
8# Dashboard → Edge Functions → [function name] → Logs tab

1// WRONG: bare import (causes BOOT_ERROR)
2import express from 'express'
3
4// CORRECT: use npm: prefix for npm packages
5import Stripe from 'npm:stripe@14'
6import { createClient } from 'npm:@supabase/supabase-js@2'
7
8// WRONG: Node.js API (not available in Deno)
9import fs from 'fs'
10import path from 'path'
11
12// CORRECT: Deno equivalent
13const file = await Deno.readTextFile('./data.json')
14
15// WRONG: relative import without .ts extension
16import { helper } from '../_shared/utils'
17
18// CORRECT: include the .ts extension
19import { helper } from '../_shared/utils.ts'

1// Add timeout to fetch requests
2const controller = new AbortController()
3const timeoutId = setTimeout(() => controller.abort(), 10000) // 10 second timeout
4
5try {
6  const response = await fetch('https://api.example.com/data', {
7    signal: controller.signal,
8    headers: { 'Authorization': 'Bearer ...' },
9  })
10  clearTimeout(timeoutId)
11
12  if (!response.ok) {
13    console.error(`API returned ${response.status}: ${await response.text()}`)
14    throw new Error(`API error: ${response.status}`)
15  }
16
17  const data = await response.json()
18  console.log(`API returned ${data.length} items`)
19} catch (error) {
20  if (error.name === 'AbortError') {
21    console.error('Request timed out after 10 seconds')
22  }
23  throw error
24}