# FAQ

Common questions about charges, failures, how long results stay and API keys.

If your question is not here, contact us with the `trace_id` or the task ID.

## Charges

### Are failed tasks charged?

No. Once a failed or cancelled task is settled, its final charge and amount due are zero and the whole reservation is released. See [How billing works](./api-docs-en-billing.md#free).

### Why is the reservation larger than the final charge?

At creation we reserve the largest usage the request can produce; after completion the task is settled on actual usage and the rest returns to your balance.

## Tasks

### My request timed out. Should I send it again?

Yes, with the same body and the same `Idempotency-Key`. If the last attempt in fact succeeded, you get the original task back, and nothing is created or charged twice. See [Idempotency and retries](./api-docs-en-idempotency.md#retry).

### Can I cancel a task that is generating?

Only before generation starts. After that, cancelling returns `not_effective` and the task continues and is settled as usual.

### How long can I download a result?

The result is kept until `expires_at`, 7 days after it is ready by default. Each task read returns a fresh `url` that works for up to 24 hours and never after `expires_at`. Save the file to your own storage in time; after `expires_at` `url` is null.

### Why does a task return `task_not_found`?

Tasks are separated by team. An unknown task ID and one of another team both return `404 task_not_found`.

## API keys and callbacks

### What if an API key leaks?

Suspend it at once on the [API keys](./integration.html) page of the console, create a new one and replace the value on your servers.

### Why didn't a callback arrive?

Check that the callback address is verified and not removed in the console, and that `callback_url` matches it byte for byte. Failed deliveries are retried for 7 days, and the console shows the delivery records. Whether or not a callback arrives, the task's status and result come from reading the task.

## Next steps

- [Handle errors](./api-docs-en-errors.md): The shape of error responses, and which errors you can retry as they are.
- [How billing works](./api-docs-en-billing.md): Funds for the upper bound are reserved at creation and settled on actual usage; failed and cancelled tasks are free.