# Edge Function 404 error response

The edge function is not recognized by Supabase, or its deployed bundle cannot be found.

## Context for the error

If the Supabase Edge Function Runtime does not recognize the function specified in the URL endpoint:

```sh
https://PROJECT_REF.supabase.co/functions/v1/UNRECOGNIZED_FUNCTION_NAME
```

then the runtime will return a 404 error.

## Solving the error

### Step 1: Identifying the error

Note: If the tests return a 404 but do not match the criteria below, the error is coming from your app's logic.

### Inspecting the return message from the request

Caution: Platform 404 errors cannot be detected in the browser. Instead, to confirm 404s from the browser, you must [check the logs](#inspecting-the-logs) instead.

Browsers misreport 404s as generic `CORS errors`. As a result, the [Supabase JavaScript client](https://supabase.com/docs/reference/javascript/introduction) surfaces only a generic message: `Failed to send a request to the Edge Function`.

When an edge function fails due to a platform 404 error, it will return the error:

```json
{
  "code": "NOT_FOUND",
  "message": "Requested function was not found"
}
```

A different platform 404 error, `NOT_FOUND_FUNCTION_BLOB`, can occur when the function name is recognized but the runtime cannot find the deployed bundle. This can happen even when the function appears as `ACTIVE` in the dashboard, because the status shows that the function record exists while the actual deployment bundle is missing or inaccessible:

```json
{
  "code": "NOT_FOUND_FUNCTION_BLOB",
  "message": "Function deployment bundle not found"
}
```

The difference between the two errors is:

- `NOT_FOUND`: The function name in the request URL is not recognized.
- `NOT_FOUND_FUNCTION_BLOB`: The function name is recognized, but the runtime cannot find the deployed bundle.

### Inspecting the logs

Note: Always configure an appropriate time frame when querying the logs

![image](/docs/img/troubleshooting/edge_function_404_set_timeframe.png)

You cannot inspect the function dashboard to find platform 404 errors, instead, run the below query in the [SQL Editor](https://supabase.com/dashboard/project/_/sql/new?skip=true\&source=logs\&content=select%20distinct%0A%20%20log_attributes%5B%27request.pathname%27%5D%20as%20function_name%2C%0A%20%20log_attributes%5B%27response.status_code%27%5D%20as%20status_code%2C%0A%20%20case%0A%20%20%20%20when%20log_attributes%5B%27execution_id%27%5D%20%3D%20%27%27%20then%20%27FUNCTION_NOT_FOUND%27%0A%20%20%20%20else%20%27FUNCTION%20RECOGNIZED%3A%20custom%20404%20message%20in%20app%20logic%27%0A%20%20end%20as%20type_of_404%0Afrom%20logs%0Awhere%0A%20%20source%20%3D%20%27function_edge_logs%27%0A%20%20and%20toInt32OrZero%28log_attributes%5B%27response.status_code%27%5D%29%20%3D%20404%0Alimit%2010%3B). The results show all requests that reached Supabase but were rejected as unrecognizable.

```sql
select distinct
  log_attributes['request.pathname'] as function_name,
  log_attributes['response.status_code'] as status_code,
  case
    when log_attributes['execution_id'] = '' then 'FUNCTION_NOT_FOUND'
    else 'FUNCTION RECOGNIZED: custom 404 message in app logic'
  end as type_of_404
from logs
where
  source = 'function_edge_logs'
  and toInt32OrZero(log_attributes['response.status_code']) = 404
limit 10;
```

### Step 2: Check the function for typos

In your code, make sure your function name doesn't have any typos, such as:

- miscapitalization
- em-dashes instead of dashes
- misplaced characters
- unnecessary slashes `///`

### Step 3: Try calling the function from the dashboard

When selecting your function in the [Function Dashboard](https://supabase.com/dashboard/project/_/functions), you should have the option to make a test call:

![image](/docs/img/troubleshooting/edge_function_404_test_call.png)

If the call works, consider double checking your code for typos or to see if it is overwriting the function name dynamically. Otherwise, go on to step 4.

### Step 4: Redeploy the function

If step 3 fails, it may be a sign of an internal bug and it may be necessary to redeploy your function. The same applies if you see the `NOT_FOUND_FUNCTION_BLOB` error, which means the function is recognized but its deployed bundle cannot be found. This can occur even when the function appears as `ACTIVE` in the dashboard.

This can be done within the [Function Dashboard](https://supabase.com/dashboard/project/_/functions) under the respective function's code tab:

![image](/docs/img/troubleshooting/edge_function_404_redeploy.png)

Alternatively, if you develop locally, you can redeploy the function with the [Supabase CLI](https://supabase.com/docs/guides/local-development/cli/getting-started?queryGroups=platform\&platform=macos):

```sh
# Redeploy one affected function
supabase functions deploy FUNCTION_NAME

# Or redeploy all functions if several are affected
supabase functions deploy
```

After redeploying, retry the request. If the error persists, write in a ticket to [Supabase Support](https://supabase.com/dashboard/support/new).

## Additional resources

- [Securing Edge Functions](https://supabase.com/docs/guides/functions/auth)
- [Debugging Edge Functions](https://supabase.com/docs/guides/functions/logging)
- [Quickstart Deployment: Dashboard](https://supabase.com/docs/guides/functions/quickstart-dashboard)
- [Quickstart Deployment: CLI](https://supabase.com/docs/guides/functions/quickstart)