> For the complete documentation index, see [llms.txt](https://docs.senmo.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.senmo.io/segment-ledger/errors.md).

# Errors

Common errors include:

#### 400 Bad Request

Invalid request payload, missing required fields, or invalid status transition.

```json
{
  "error": "Invalid transaction status transition"
}
```

#### 401 Unauthorized / 403 Forbidden

Missing or invalid authentication token or API key.

```json
{
  "error": "Invalid API key"
}
```

#### 404 Not Found

The requested ledger, account, transaction, or user was not found.

```json
{
  "error": "Account not found"
}
```

#### 409 Conflict

Resource conflict or duplicate state.

#### 500 Internal Server Error

Unexpected server-side failure.