---
id: 'functions-error-codes'
title: 'Error codes'
description: 'Edge Functions can return the following error codes.'
subtitle: 'Understand the error codes returned by Edge Functions to properly debug issues and handle responses.'
---

{/* supa-mdx-lint-disable Rule001HeadingCase */}

When an Edge Function request fails, the response includes a `sb-error-code` header that identifies the specific error.
You can inspect this header in your HTTP client or application code to detect and handle errors programmatically.

```js
const response = await fetch('<your-function-url>')

if (!response.ok) {
  const errorCode = response.headers.get('sb-error-code')
  console.error('Edge Function error:', errorCode)
}
```

## Bad Implementation Errors

These errors are caused by issues in your function's code or logic which requires updating its implementation.

### EDGE_FUNCTION_ERROR

**Cause:** Your Edge Function is throwing an unhandled error or resulting a 5XX code.

```ts
// ...

function process() {
  throw new Error('Some unhandled error')
}

export default {
  fetch: withSupabase({ auth: 'none' }, async () => {
    process()

    return new Response()
  }),
}
```

**Solution:**

- Ensure you are catching errors in your code logic with try-catch blocks.

```ts
function process() {
  throw new Error('Some unhandled error')
}

// ...

try {
  process()
  return new Response()
} catch (e) {
  console.error('Process fail:', e)
  return new Response(null, { status: 500 })
}
```

### IDLE_TIMEOUT

**Cause:** Your Edge Function did not respond within the [request timeout limit](/docs/guides/functions/limits).

**Common causes:**

- Long-running database queries
- Slow external API calls
- Infinite loops or blocking operations

**Solution:**

- Optimize slow operations
- Add timeout handling to external requests
- Consider breaking large operations into smaller chunks

### WORKER_RESOURCE_LIMIT, WORKER_LIMIT

**Cause:** Your Edge Function execution was stopped due to exceeding resource limits. Edge Function logs should indicate which [resource limit](/docs/guides/functions/limits) was exceeded.

**Common causes:**

- Memory usage exceeded available limits
- CPU time exceeded execution quotas
- Too many concurrent operations

**Solution:** Check your Edge Function logs to see which resource limit was exceeded, then optimize your function accordingly.

### WORKER_ERROR

**Cause:** Your Edge Function threw an uncaught exception.

```ts
// ...

function initSomething() {
  throw new Error('Some unhandled error')
}

initSomething() // Error threw outside request handler

export default {
  fetch: withSupabase({ auth: 'none' }, async () => {
    return new Response()
  }),
}
```

**Common causes:**

- Unhandled JavaScript errors in your function code, outside request handler
- Missing error handling for async operations
- Invalid JSON parsing

**Solution:** Check your Edge Function logs to identify the specific error and add proper error handling to your code.

### INVALID_RESPONSE_STATUS_CODE

**Cause:** Your Edge Function is returning an invalid HTTP status code — not equal to `101` and outside the range `[200, 599]`

**Common causes:**

- Proxying an external service that returns an invalid HTTP status code

```ts
// ...

export default {
  fetch: withSupabase({ auth: 'none' }, async (req) => {
    // Fails in case this proxied server return a status >599
    return fetch('https://some-server-to-proxy', {
      method: req.method,
      headers: req.headers,
      body: req.body,
    })
  }),
}
```

**Solution:**

- Ensure you are returning a valid HTTP status code
- For proxy endpoints, do not return the `fetch()` result directly; instead return a new `Response` wrapped in a try-catch block

```ts
// ...

export default {
  fetch: withSupabase({ auth: 'none' }, async (req) => {
    try {
      const res = await fetch('https://some-server-to-proxy', {
        method: req.method,
        headers: req.headers,
        body: req.body,
      })

      // Creating a 'new Response()' ensures constructor checks
      return new Response(await res.body, {
        headers: res.headers,
        status: res.status,
        statusText: res.statusText,
      })
    } catch (e) {
      console.error('Proxy Error', e)
      return new Response(null, { status: 502 })
    }
  }),
}
```

## Authentication Errors

These errors occur when the request contains a missing, malformed, or unsupported JWT token. Fixing them requires ensuring your requests include a valid authorization header, or disabling JWT verification for public endpoints.
For further information, see [Authorization headers](/docs/guides/functions/auth-headers) and [Securing Edge Functions](/guides/functions/auth).

### UNAUTHORIZED_NO_AUTH_HEADER

**Cause:** The Edge Function has JWT verification enabled, but the request is missing the `Authorization` or `apikey` header.

**Solution:**

- Ensure you are passing a valid JWT token in the `Authorization` header
- Check that you are sending an API key in the `apikey` header
- For webhooks or public endpoints, consider disabling JWT verification

### UNAUTHORIZED_ASYMMETRIC_JWT

**Cause:** The Edge Function has JWT verification enabled, but the `Authorization` header contains an invalid asymmetric `ES256 | RS256` token.

**Solution:**

- Ensure you are passing a valid user JWT token in the `Authorization` header
- Check that your token has not expired

### UNAUTHORIZED_LEGACY_JWT

**Cause:** The Edge Function has JWT verification enabled, but the `Authorization` header contains an invalid legacy `HS256` token.

**Solution:**

- Ensure you are passing a valid legacy JWT token in the `Authorization` header
- Check that your token has not expired
- Verify that the legacy JWT secret has not been revoked or disabled

### UNAUTHORIZED_UNSUPPORTED_TOKEN_ALGORITHM

**Cause:** The Edge Function has JWT verification enabled, but the `Authorization` header does not contain an `ES256 | RS256 | HS256` token.

**Solution:**

- Ensure you are passing a valid Supabase-issued JWT token in the `Authorization` header

### UNAUTHORIZED_INVALID_JWT_FORMAT

**Cause:** The Edge Function has JWT verification enabled, but the `Authorization` header does not follow the `Bearer <JWT Token>` format.

**Solution:**

- Check that you are passing `Bearer <JWT Token>` in the `Authorization` header
- Ensure you are sending an API key in the `apikey` header instead of `Authorization`
- For webhooks or public endpoints, consider disabling JWT verification

## Request Errors

These errors indicate issues with the request itself, which typically require changing how the function is called.

### RATE_LIMIT_EXCEEDED

**Cause:** The platform detected [recursive or nested function call](/docs/guides/functions/recursive-functions) behavior.

**Common causes:**

- Multiple function-to-function calls
- Recursive or circular calls

**Solution:**

- Use the suggested retry window in seconds from the error message before calling your function again
- Ensure you are not performing unnecessary individual calls; use batch operations where possible
- Delegate large workloads to queues instead of recursively calling other Edge Functions

### INVALID_URL

**Cause:** The platform rejected a malformed URL.

**Solution:**

- Ensure you are calling with a valid [formatted URL](https://developer.mozilla.org/en-US/docs/Web/API/URL/URL)

---

## Server Errors

These errors indicate issues with function loading, execution, or the underlying platform.

### NOT_FOUND

**Cause:** The Edge Function metadata or files were not found or are missing in the specific region.

**Solution:** Try redeploying your function and wait a few minutes to make sure all regions have been updated.

### BOOT_ERROR

**Cause:** Your Edge Function failed to start.

**Common causes:**

- Syntax errors preventing the function from loading
- Import errors or missing dependencies
- Invalid function configuration

**Solution:** Check your Edge Function logs and also verify that your function code can be executed locally with `supabase functions serve`.

### LOAD_FUNCTION_ERROR

**Cause:** The platform was unable to load your function metadata or files.

**Solution:**

- Try calling your function again after a short delay
- If the problem persists, contact support

### LOAD_FUNCTION_METADATA_ERROR

**Cause:** The platform could not fetch your function metadata, possibly due to external cache issues.

**Solution:**

- Wait a few minutes before calling your function again
- If the problem persists, contact support

### LOAD_FUNCTION_INVALID_ENTRYPOINT_PATH_ERROR

**Cause:** Your Edge Function metadata is broken or contains an invalid entrypoint.

**Solution:**

- Try redeploying your function
- If the problem persists, contact support