# Chat Debug Data Retention

Coder Agents automatically cleans up old chat debug data to manage database
growth. Debug data includes persisted debug runs and their associated debug
steps.

This setting is independent from [conversation data retention](./chat-retention.md),
which only purges archived conversations and orphaned files.

## How it works

A background process removes debug runs older than the configured retention
period. When a debug run is deleted, its debug steps are deleted via cascade.

The retention clock uses the debug run's `updated_at` value, which reflects the
last write to the debug run. It does not use the chat archive time. If a debug
run remains in progress for an unusually long period, such as after broken
finalization, it can still be purged once its `updated_at` value is older than
the cutoff.

## Configuration

Navigate to the **Agents** page, open **Settings**, and select the
**Lifecycle** tab to configure chat debug data retention. The default is 30 days.
Set the value to `0` to disable debug data retention entirely. The maximum value
is `3650` days.

Use the experimental admin API to read or update the value:

```text
GET  /api/experimental/chats/config/debug-retention-days
PUT  /api/experimental/chats/config/debug-retention-days
```

## Interaction with conversation retention

Conversation retention and debug data retention are orthogonal controls:

| Control                | What it deletes                                             | Default |
|------------------------|-------------------------------------------------------------|---------|
| Conversation retention | Archived conversations and orphaned files                   | 30 days |
| Debug data retention   | Debug runs and debug steps, based on debug run `updated_at` | 30 days |

Deleting a chat still deletes its debug data immediately via cascade, regardless
of the debug retention window. Unarchiving a chat does not restore debug data
that was already purged.