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

# M005: Key not recognized

> M005 is returned when no harness matches a correctly shaped mnfst_ key.

## What you saw

```text theme={"theme":{"light":"github-light","dark":"github-dark"}}
[🦚 Manifest M005] I don't recognize this key. It might have been rotated or deleted. Grab the current one from the dashboard.
See https://manifest.build/llm-gateway/docs/errors/M005
```

## Why it happened

The token shape is right (`mnfst_...`) but no matching harness exists. Usually that means the key was rotated and your client still has the old value, or the harness itself was deleted, or you copied a key from a different workspace.

## How to fix it

1. Open the [dashboard](https://app.manifest.build), find your harness, and copy the current key.
2. Paste it into your client's config. If the harness is gone, create a new one and copy its key.
3. On a self-hosted install, double-check that your client is hitting the right backend URL.

## Related

* [M003: Invalid key format](/llm-gateway/docs/llm-gateway/docs/errors/M003)
* [M004: Key expired](/llm-gateway/docs/llm-gateway/docs/errors/M004)
* [M001: Missing Authorization header](/llm-gateway/docs/llm-gateway/docs/errors/M001)
* [Self-hosted setup](/llm-gateway/docs/llm-gateway/docs/self-hosted)
* [All error codes](/llm-gateway/docs/llm-gateway/docs/errors)