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

# unauthenticated

> The Authorization header is missing, malformed, or the API key is revoked.

The request didn't carry a valid letmepost API key. This is about *your* key — not the upstream platform token. For platform token issues see [`platform_auth_failed`](/errors/platform_auth_failed).

## What triggers it

* No `Authorization` header.
* Header doesn't start with `Bearer `.
* Key is unknown (typo, revoked, deleted org).
* Key prefix doesn't match the environment (e.g., `lmp_test_…` against the production base URL).

## Response shape

```json unauthenticated.json theme={"system"}
{
  "error": {
    "code": "unauthenticated",
    "message": "Missing or invalid Authorization header.",
    "remediation": "Send 'Authorization: Bearer lmp_live_…' (or lmp_test_…) on every request.",
    "docUrl": "https://docs.letmepost.dev/errors/unauthenticated",
    "requestId": "req_..."
  }
}
```

## Remediation

1. Mint or rotate a key in the dashboard's **API keys** page.
2. Confirm the prefix matches your environment.
3. Confirm the key wasn't revoked — revocation is immediate.

## Related

* [Authentication](/authentication) — full key shape + scoping rules.
* [`unauthorized`](/errors/unauthorized) — authenticated but not allowed.
* [`platform_auth_failed`](/errors/platform_auth_failed) — upstream platform token issue.