---
title: 5001: attachment source capacity is busy; retry shortly | API Docs
description: attachment source capacity is busy; retry shortly
---

attachment source capacity is busy; retry shortly. This is an HTTP 503: a dependency is unavailable right now.

## Troubleshooting

- Wait the number of seconds in the `Retry-After` header (and `retry_after` in the body), then retry the same request unchanged.
- Nothing about the request is wrong: this is backpressure, so re-sending it after the wait is the correct handling.
- Spread sustained load rather than retrying in a tight loop; the window is per brand.