Edge Functions logging

Logs are provided for each function invocation, locally and in hosted environments.

Accessing logs

Production

Open the logs for a function in the Dashboard:

1. Go to the Edge Functions section of the Dashboard.
2. Select your function from the list.
3. Select the Logs tab.

The Logs tab shows one list with both kinds of events for the function:

• Invocations: one row for each HTTP request the function handled, with the status code and execution time.
• Console logs and events: output from console.log, console.warn, and console.error, uncaught exceptions, and boot and shutdown events.

Development

When developing locally you will see error messages and console log statements printed to your local terminal window.

Explore logs in the Dashboard

Filter the list

Use the filter bar above the list to narrow the events:

For an invocation, the level follows the HTTP status code: 2xx is success, 4xx is warning, and 5xx is error. For a console log or event, error and fatal map to error, warn and warning map to warning, and other levels map to success.

Select Live to fetch new events automatically. Select it again to pause. Choosing a time range or sorting the list also stops live mode.

Inspect an event

Select a row to open the detail panel. The panel has these tabs:

For an invocation, Overview has these sections:

• Network: host, method, path, and client, when available.
• Edge Function: status, function path, execution time, and execution ID. It includes a Function Details section with the function ID, execution region, number of function logs, method, and user agent.
• Attributes: the remaining fields of the event, grouped into Details, Request, Response, request and response headers, and other sections. A section appears only when the event has fields for it.

What invocation logs contain

Invocation logs record the request method, path, and host, the response status code, the execution time, and a limited set of headers.

Request and response bodies are not logged or retained. Logs do not contain the payload a client sent or the data your function returned, and you can't view them in the Dashboard. To see a body while debugging, log the part you need from your function code with console.log, taking care not to log sensitive data.

Only a subset of request and response headers is kept. The function_edge_logs source records these headers:

• Request headers: accept, content-length, host, and user-agent.
• Response headers: content-length, content-type, date, server, and vary.

Other headers, including authorization and custom headers, reach your function but are not part of the invocation log. To inspect them, log them from your function as shown in Logging request headers. For the full list of fields, see the Log field reference.

Log event types

Automatic logs

Your functions automatically capture several types of events:

• Uncaught exceptions: Uncaught exceptions thrown by a function during execution are automatically logged. You can see the error message and stack trace in the Logs tool.
• Custom log events: You can use console.log, console.error, and console.warn in your code to emit custom log events. These events also appear in the Logs tool.
• Boot and Shutdown Logs: The Logs tool extends its coverage to include logs for the boot and shutdown of functions.

Custom logs

You can add your own log messages using standard console methods:

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Deno.serve(async (req) => {
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  try {
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    const { name } = await req.json()
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    if (!name) {
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      // Log a warning message
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      console.warn('Empty name parameter received')
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    }
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    // Log a message
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    console.log(`Processing request for: ${name}`)
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    const data = {
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      message: `Hello ${name || 'Guest'}!`,
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    }
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    return new Response(JSON.stringify(data), {
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      headers: { 'Content-Type': 'application/json' },
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    })
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  } catch (error) {
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    // Log an error message
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    console.error(`Request processing failed: ${error.message}`)
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    return new Response(JSON.stringify({ error: 'Internal Server Error' }), {
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      status: 500,
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      headers: { 'Content-Type': 'application/json' },
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    })
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  }
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})

Logging tips

Logging request headers

When debugging Edge Functions, a common mistake is to try to log headers to the developer console via code like this:

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// ❌ This doesn't work as expected
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Deno.serve(async (req) => {
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  console.log(`Headers: ${JSON.stringify(req.headers)}`) // Outputs: "{}"
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})

The req.headers object appears empty because Headers objects don't store data in enumerable JavaScript properties, making them opaque to JSON.stringify().

Instead, you have to convert headers to a plain object first, for example using Object.fromEntries.

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// ✅ This works correctly
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Deno.serve(async (req) => {
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  const headersObject = Object.fromEntries(req.headers)
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  const headersJson = JSON.stringify(headersObject, null, 2)
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  console.log(`Request headers:\n${headersJson}`)
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})

This results in something like:

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Request headers: {
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    "accept": "*/*",
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    "accept-encoding": "gzip",
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    "authorization": "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJzdXBhYmFzZSIsInJlZiI6InN1cGFuYWNobyIsInJvbGUiOiJhbm9uIiwieW91IjoidmVyeSBzbmVha3ksIGh1aD8iLCJpYXQiOjE2NTQ1NDA5MTYsImV4cCI6MTk3MDExNjkxNn0.cwBbk2tq-fUcKF1S0jVKkOAG2FIQSID7Jjvff5Do99Y",
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    "cdn-loop": "cloudflare; subreqs=1",
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    "cf-ew-via": "15",
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    "cf-ray": "8597a2fcc558a5d7-GRU",
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    "cf-visitor": "{\"scheme\":\"https\"}",
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    "cf-worker": "supabase.co",
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    "content-length": "20",
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    "content-type": "application/x-www-form-urlencoded",
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    "host": "edge-runtime.supabase.com",
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    "my-custom-header": "abcd",
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    "user-agent": "curl/8.4.0",
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    "x-deno-subhost": "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiIsImtpZCI6InN1cGFiYXNlIn0.eyJkZXBsb3ltZW50X2lkIjoic3VwYW5hY2hvX2M1ZGQxMWFiLTFjYmUtNDA3NS1iNDAxLTY3ZTRlZGYxMjVjNV8wMDciLCJycGNfcm9vdCI6Imh0dHBzOi8vc3VwYWJhc2Utb3JpZ2luLmRlbm8uZGV2L3YwLyIsImV4cCI6MTcwODYxMDA4MiwiaWF0IjoxNzA4NjA5MTgyfQ.-fPid2kEeEM42QHxWeMxxv2lJHZRSkPL-EhSH0r_iV4",
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    "x-forwarded-host": "edge-runtime.supabase.com",
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    "x-forwarded-port": "443",
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    "x-forwarded-proto": "https"
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}