# Error Response

{% hint style="danger" %}
All Login and Myinfo apps must follow Singpass' [FAPI 2.0-compliant authentication API](/docs/technical-specifications/integration-guide.md) by 31 Dec 2026.

The specifications on this page apply to you only if you are maintaining an existing Login / Myinfo (v5) integration. We encourage you to [migrate](/docs/technical-specifications/migration-guides/login-myinfo-v5-apps.md) early to avoid service disruptions.
{% endhint %}

Singpass APIs are RESTful in design and communicate classes of errors based on the **HTTP status code**. The status code should be used to determine if the error is caused by consumer or provider. Consumers should log the HTTP status code along with the `id` and/or `trace_id` of the error.

<table><thead><tr><th width="191">HTTP Status</th><th>Description</th></tr></thead><tbody><tr><td>4xx</td><td><p>Errors caused by API consumer. You can expect codes such as 400, 401, 403, 404 etc. if incorrect requests are made to APIs.</p><p>Example: <strong>400 Bad Request due to invalid/missing request arguments</strong></p></td></tr><tr><td>5xx</td><td><p>Errors caused by API provider or its dependencies. You can expect codes such as 500, 502, 503 etc if there is an issue on Singpass or its dependencies.</p><p>Example: <strong>500: Internal Server Error due to some kind of programming error.</strong></p></td></tr></tbody></table>

Example: Invalid Request Parameters

```http
HTTP/1.1 400 Bad Request
Connection: keep-alive
Cache-Control: no-cache, no-store, must-revalidate
Transfer-Encoding: chunked
Content-Type: application/json
Date: Thu, 26 Sep 2024 03:36:41 GMT
Content-Length: 190

{
  "id" : "bcba4bc3-534e-4891-bfa2-e872b4502d80",
  "error" : "CLIENT_SIDE_ERROR",
  "error_description" : "This is an invalid request.",
  "trace_id" : "66f4d6c93a23476106150eb7c40d7dc9"
}
```

Example: Server Error

```http
HTTP/1.1 500 Internal Server Error
Cache-Control: no-cache, no-store, must-revalidate
X-XSS-Protection: 0
X-Frame-Options: DENY
Date: Thu, 26 Sep 2024 03:36:41 GMT
Connection: keep-alive
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers
X-Content-Type-Options: nosniff
Transfer-Encoding: chunked
Content-Type: application/json
Content-Length: 192

{
  "id" : "bcba4bc3-534e-4891-bfa2-e872b4502d80",
  "error" : "SERVER_SIDE_ERROR",
  "error_description" : "An unexpected error occurred.",
  "trace_id" : "66f4d6c97ef952fbff9f2d20f6b826f9"
}
```

| Path                | Type                             | Description                                                                                                                                                                                                                                                                                               |
| ------------------- | -------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `id`                | `String`                         | The unique identifier for this error/request. Please log this identifier for support and debugging purposes.                                                                                                                                                                                              |
| `trace_id`          | `String InstanceOfAssertFactory` | (Optional) An auxiliary id for request correlation across services. Please also log this identifier for operational support and debugging purposes.                                                                                                                                                       |
| `error`             | `String`                         | Error code representing broad class of error; likely to be one of CLIENT\_SIDE\_ERROR, ARGUMENTS\_NOT\_VALID, SERVER\_SIDE\_ERROR, TOO\_MANY\_REQUESTS. However, specific error codes can be returned for some endpoints, in which case you may find more details in the documentation for that endpoint. |
| `error_description` | `String`                         | Returns human readable general information about the reason for the error. Note that due to security reasons; detailed information is unlikely to be available in this message.                                                                                                                           |


---

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Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.developer.singpass.gov.sg/docs/technical-specifications/singpass-authentication-api/error-response.md?ask=<question>
```

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The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.