Defining parameters for an operation

Operation parameters can, for the URL path associated with that specific operation, define variable elements of the URL path, query parameters, headers, or body parameters.

About this task

  • This task relates to configuring an OpenAPI 3.0 API definition. For details on how to configure an OpenAPI 2.0 API definition, see Editing an OpenAPI 2.0 API definition.
  • OpenAPI 3.0 APIs are supported only with the DataPower® API Gateway, not with the DataPower Gateway (v5 compatible).
  • For details of current OpenAPI 3.0 support limitations, see OpenAPI 3.0 support in IBM® API Connect.

You can complete this task either by using the API Designer UI application, or by using the browser-based API Manager UI.

An operation parameter overrides a parameter of the same name defined on the parent Path; see Defining parameters for a Path.

A parameter is similar to a header, with the following differences:
  • Parameters carry actual data and are available to end users, headers carry meta data associated with a request or response and are hidden from end users.
  • A parameter can have various locations, the location of a header is always set to header.
  • A parameter can have various format styles, the style of a header is always simple.
For more information on headers, see Creating a header.

At any time, you can switch directly to the underlying OpenAPI YAML source by clicking the Source icon OpenAPI Source icon. To return to the design form, click the Form icon Form icon.


  1. Open the API for editing, as described in Editing an OpenAPI 3.0 API definition.
  2. Expand Paths, then expand the required Path.
  3. Expand Operations, then expand the required operation.
  4. You can either create a new operation parameter, or edit any existing parameter.
    • To create an operation parameter, click the add icon OpenAPI 3.0 API add icon alongside Parameter, then refer to Creating a parameter.
    • To edit an existing operation parameter, click the parameter name in the navigation pane, then refer to Editing a parameter.