## TL;DR
Asana sends webhooks for events including deletions, and by the time your handler asks for the task, it's gone. 'Task not found' on a webhook event usually means the task was deleted between the event and your lookup, or the webhook's credential lost access. Treat missing tasks as expected: log and skip, don't retry forever.

## The query

```text
asana webhook task not found
```

## Use this when

- Asana webhook handlers fail on task lookups
- The task shows in Asana but the API says not found
- Failures cluster around task deletions


## Not for

- Asana webhook signature failures
- Webhook events not arriving
- Asana authentication errors


## Steps

### 1. Check the event type before the lookup

Read the webhook event: if it's a deletion event, the task is supposed to be gone. Don't look it up; handle the deletion (remove your local copy) and move on.

Expected output: deletion events handled without a task lookup.

### 2. Make missing tasks a normal path

In the handler, treat a 404 on the task fetch as 'task gone', log it, and return success. Retrying a deleted task's lookup burns quota and pages nobody.

Expected output: a 404 branch that logs and exits cleanly.

### 3. Verify the credential's project access

If non-deletion events also 404, the webhook's credential may have lost access to the project. Check the credential's memberships against the task's project.

Expected output: the credential confirmed as a member of the task's project.

### 4. Reconcile with periodic sync

Webhooks plus deletions drift. Run a periodic sync that reconciles your local task store against Asana, catching the deletes and moves webhooks missed.

Expected output: a scheduled reconciliation job covering webhook gaps.

## Variant phrasings

### asana webhook deleted task

Steps 1 and 2: check the event type, then skip cleanly.

### asana api task not found webhook

Step 3's access check for the non-deletion cases.

## Why it happens

Webhooks are event notifications, not state transfers: they tell you something happened, and the world may have moved on by the time you look. Deletion events are the sharpest case, but access changes and project moves create the same gap. Handlers written against a static worldview 404 on a dynamic one.

## Edge cases

- Asana may batch events. Your handler can get a create and a delete for the same task in one delivery.
- Webhook secrets rotate. A 401 storm after rotation looks like missing tasks if you misread it.
- Test with real deletions, not just creates. The delete path is where handlers break.

## Provenance

Resolved from the public thread: https://vectle.com/posts/pst_PXLm-9m9j6SMnMdas79nlA