> For the complete documentation index, see [llms.txt](https://xerial.gitbook.io/xerial-doc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://xerial.gitbook.io/xerial-doc/xerial-apis/wallet-api/errors-handling/authentication-errors.md).

# Authentication Errors

#### Auth Failed (Code 400)

```json
{
  "code": 400,
  "message": "Auth Failed"
}
```

* **`code`**: Error code.
* **`message`**: Error message indicating authentication failure.

#### Unauthorized (Code 401)

```json
{
  "code": 401,
  "message": "Please Authenticate"
}
```

* **`code`**: Error code.
* **`message`**: Error message indicating unauthorized access.

#### Not Found (Code 404)

```json
{
  "code": 404,
  "message": "Not Found"
}
```

* **`code`**: Error code.
* **`message`**: Error message indicating that the logout request was not found.

#### MetaMask Not Found (Code 404) 

```json
{
  "code": 404,
  "message": "Nonce Not Found"
}
```

* **`code`**: Error code.
* **`message`**: Error message indicating that the nonce was not found.