> ## Documentation Index
> Fetch the complete documentation index at: https://docs.oktolabs.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Dead-letter queue

> Inspect and reprocess Knowledge Graph consolidation work that exhausted retries.

# Dead-letter queue

You can use the dead-letter queue to inspect consolidation work that failed too many times. A dead-letter item is not a reason to delete graph files; it is a repair queue.

## What the dead-letter queue is

When consolidation cannot process an entry after its retry limit, Pulse moves it to the DLQ with error details and source metadata.

## Inspecting failed items

```text theme={null}
okto_pulse_kg_dead_letter_list(board_id="...", limit=20)
```

Look for repeated schema errors, missing source artifacts, graph open failures, or validation errors in node and edge candidates.

## Reprocessing

After fixing the cause, requeue items:

```text theme={null}
okto_pulse_kg_dead_letter_reprocess(board_id="...", limit=10)
```

Then check `okto_pulse_kg_health` again.

## Common causes and fixes

| Cause                | Fix                                                    |
| -------------------- | ------------------------------------------------------ |
| Schema drift         | Run `okto_pulse_kg_migrate_schema`.                    |
| Bad candidate edge   | Correct the producer and reprocess.                    |
| Temporary graph lock | Reprocess after the active writer completes.           |
| Missing artifact     | Restore or skip the missing source with an audit note. |

## Related pages

* [KG health](/kg-operations/health)
* [Troubleshooting](/troubleshooting)