> For the complete documentation index, see [llms.txt](https://docs.developer.singpass.gov.sg/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.developer.singpass.gov.sg/docs/client-initiated-backchannel-authentication-ciba/error-response.md).

# Error Response

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.

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: Fri, 14 Feb 2025 01:37:57 GMT
Content-Length: 190

{
  "id" : "bcba4bc3-534e-4891-bfa2-e872b4502d80",
  "error" : "CLIENT_SIDE_ERROR",
  "error_description" : "This is an invalid request.",
  "trace_id" : "67ae9e7585c905b608ca205f42270eff"
}
```

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: Fri, 14 Feb 2025 01:37:57 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" : "67ae9e75bce5bd9bef0c2a4128d71c7f"
}
```

| 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.                                                                                                                           |


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

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

```
GET https://docs.developer.singpass.gov.sg/docs/client-initiated-backchannel-authentication-ciba/error-response.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.