Help Center/ Cognitive Engagement Center/ User Access--Web Client Access (RESTful)/ Overview/ RESTful API Format/ Response Message
Updated on 2024-03-05 GMT+08:00
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Response Message

A response message consists of a status line, response header, and response body. Table 1 describes the response message format.

Table 1 Response message format

HTTP/HTTPS Response Message

HTTP/HTTPS response line

HTTP-Version Status-Code Reason-Phrase

NOTE:

There is a space between HTTP-Version and Status-Code, and between Status-Code and Reason-Phrase. There is a carriage return after Reason-Phrase.

Response header

Content-Type:application/json;charset=UTF-8

...

Blank line

CRLF

Message body (optional)

Business request message (JSON description)

Status Line

HTTP-Version Status-Code Reason-Phrase CRLF

In the preceding information:

  • HTTP-Version: HTTP version number of the server.
  • Status-Code: response status code returned by the server.
  • Reason-Phrase: text description of a status code.

    A status code consists of three digits. The first digit defines the response type and has five options.

    • 1xx: Informational - The request has been received and can be further processed.
    • 2xx: Success - The request has been successfully received, parsed, and accepted.
    • 3xx: Redirection - Further operations must be performed for completing the request.
    • 4xx: Client error - The request has syntax errors or cannot be implemented.
    • 5xx: Server error - The server fails to fulfill a valid request.

    Common status codes are as follows:

    • 200 OK: The request has succeeded.
    • 400 Bad Request: The client request has syntax errors and cannot be parsed by the server.
    • 401 Unauthorized: The request is unauthorized.
    • 403 Forbidden: The server receives the request but refuses to provide services.
    • 404 Not Found: The requested resource does not exist.
    • 500 Internal Host Error: An unexpected error occurs on the server.
    • 503 Host Unavailable: The server cannot process the client request now and may be able to process the request later.

    Most of the time, 200 OK is returned:

    HTTP/1.1 200 OK (CRLF)

Response Header

A response header usually contains the following header fields:

  • Date: Mon, 12 Nov 2007 15:55:01 GMT

    Indicates the response sending time.

  • Content-Length: xxx

    Specifies the length of the entity text and is stored as bytes in decimal number.

  • Content-Type: application/json; charset=UTF-8

    Specifies the media type of the entity text sent to the recipient.

Response Body

The response body is in JSON format. For details, see the definition of each API in the following sections.

Parent topic: RESTful API Format