Control request and response content type

  • Release version: Zurich
  • Updated July 31, 2025
  • 2 minutes to read
    • Summarize
    Summarized using AI
    This content was generated using new OpenAI-powered functionality. Results are provided on an as is basis and are not guaranteed to be accurate or complete.

    Summary of Control request and response content type

    This feature in ServiceNow's Scripted REST APIs controls which content types are allowed for requests and responses. By default, the APIs supportapplication/json,application/xml, andtext/xml, along with user-defined custom content types that have JSON or XML subtypes. Proper configuration ensures that your API handles content types correctly and avoids errors.

    Show full answer Show less

    Key Features

    • Default Supported Formats: You can define default acceptable content types for request and response headers using Default supported request formats and Default supported response formats. These settings enforce proper Content-Type and Accept headers and return HTTP errors 406 or 415 when unsupported types are used.
    • Resource-Level Overrides: Content type settings can be customized per resource via Supported request formats and Supported response formats fields on the Scripted REST Service form. Note that Supported request formats applies only to PUT, POST, and PATCH methods.
    • Wildcard Support: You can specify valid content types using wildcards for flexible matching:
      • % represents a single-character wildcard (e.g., te%t matches text or test).
      • represents multiple characters, including zero (e.g., pld matches planned or placed).
    • Handling application/x-www-form-urlencoded: When accepting this content type, your API can retrieve URL-encoded key-value pairs as a JSON map accessible via request.queryParams. These parameters combine query string and request body pairs for easy processing.
    • Sending Binary Responses: To return binary data, set the response content type accordingly and write the binary stream directly using a RESTAPIResponseStream obtained by calling getStreamWriter() on the response object.

    Important Usage Notes

    • If the request body format is not a JSON or XML subtype, only the dataStream field should be used to access the request body. Attempting to use data, dataString, nextEntry(), or hasNext() with unsupported formats results in a 500 error.

    Practical Benefits for ServiceNow Customers

    By configuring allowed content types at the API and resource levels, you ensure robust handling of diverse data formats, prevent errors caused by unsupported content types, and improve interoperability with clients. Wildcard support provides flexible content type matching without strict enumeration. Handling application/x-www-form-urlencoded and binary responses enables support for common web standards and richer data exchange scenarios.

    Controls which content types are allowed in scripted REST API requests and responses.

    By default, scripted REST APIs support application/json, application/xml, and text/xml. User-defined custom content types (with json or xml subtypes) are also supported. For example, application/vnd.collection+json and application/vnd.adobe.xdp+xml are treated as JSON and XML, respectively.
    Important:
    If the request body format is not of a json or xml subtype, use only the request body dataStream field to access the request body. Using request body data, dataString, nextEntry(), or hasNext() with a non-json or non-xml format results in a 500 error response.

    Setting defaults

    You can set default values for the API using the Default supported request formats and Default supported response formats fields. These fields define acceptable values users can pass in the Content-Type and Accept request headers, respectively. If a requesting user specifies an Accept or Content-Type header not supported by the API or resource, the instance responds with an HTTP error code of 406 or 415.

    You can override these values for each resource using the Supported request formats and Supported response formats on the Scripted REST Service form.
    Note:
    The Supported request formats field appears only for PUT, POST, and PATCH resources.

    Using wildcard values

    You can use wildcard values when specifying valid content types.
    • To perform a single-character wildcard search, use the percent sign (%) character. This wildcard finds words that contain any one character in place the percent-sign-character. For example, to find words such as text or test, search for: te%t.
    • To perform a multiple-character wildcard search, use the asterisk (*) character. This wildcard finds words that contain zero or more characters in place of the asterisk-character. For example, to find words such as planned or placed, search for: pl*d.

    Using the x-www-form-urlencoded content type

    If a REST API or resource accepts the application/x-www-form-urlencoded content-type, you can retrieve the urlencoded values provided in the request as a JSON map. You can then supply these urlencoded key-value pairs as query parameters, in the request body, or both. They are combined and stored in the request parameters. Access these parameters through the request.queryParams object.

    For example, if your API is defined to accept the application/x-www-form-urlencoded content-type and your API is implemented as follows, 
    (function process(/*RESTAPIRequest*/ request, /*RESTAPIResponse*/ response) {

 response.setBody(request.queryParams);

})(request, response);
    … then the following request yields the respective response:
    POST to localhost:8080/api/now/some_api/some_resource?name3=value3&name4=value4
    Body:
    name1=value1&name2=value2
    Response:
    { "result":
    { "name4": [ "value4" ], "name3": [ "value3" ], "name2": [ "value2" ],
      "name1": [ "value1" ]
    }
}

    Sending binary type in a response

    When sending a binary type in a response, you must set the response content type and write the binary stream directly using a RESTAPIResponseStream object. You can access this object by calling getStreamWriter() on the response object. For more information, see.