Calling REST APIs by using the RESTRequest node

IBM® Integration Bus provides a RESTRequest node, which enables you to interact with external REST APIs.

Import a Swagger document and configure a RESTRequest node by completing the following steps:

1. Create a message flow to include your RESTRequest node.
   For information about creating a message flow, see Creating a message flow.
2. Configure the RESTRequest node to use an imported Swagger document that contains the operation that you want to invoke, by using one of the following methods:
   • Drag and drop an operation from the REST APIs Catalog onto the message flow canvas or onto a connection between two existing nodes in the message flow. A RESTRequest node is created automatically and configured to use the selected operation. If the operation is dropped onto a connection between two existing nodes, the RESTRequest is inserted into the flow between the two existing nodes.

     A REST APIs Catalog folder in each project in the Navigator contains a list of all the REST APIs that are available in the project for use with RESTRequest and RESTAsyncRequest nodes. Each REST API folder contains a list of all the available operations in the REST API.

   • Drag and drop a RESTRequest node from the palette onto the message flow canvas.

     When you place the RESTRequest node onto the canvas, a wizard guides you through choosing the REST API and the operation that you want to invoke. You can select an operation from the set of operations in the imported Swagger document, and specify parameter values as node properties, using XPath or ESQL expressions to select data from the input message tree.

     1. Use the Invoke an operation in a REST API page in the wizard to specify the location of the Swagger document that contains the operation that you want to use:
        • Select a Swagger document from a referenced project or from a file system

          Select this option to display a window in which you can either specify either a location in your file system, or select a Swagger document from a referenced project. If you select a Swagger document from your file system, it is copied into the project that contains your RESTRequest node.

          If you want to use a Swagger document from a shared library that is not referenced, you must reference the shared library first, and then add the RESTRequest node.

        • Retrieve a Swagger document from a URL using HTTP or HTTPS

          Select this option to display a window in which you can specify a URL to a Swagger document. This Swagger document is downloaded and stored in the project containing the RESTRequest node.

        • Configure the REST request node manually

          Select this option to close the wizard without making any changes to the RESTRequest node. You can then optionally drag and drop an operation from the REST APIs Catalog in the Navigation onto the RESTRequest node in the message flow, and it is configured automatically to use that operation.

     2. If you selected either Select a Swagger document from a referenced project or from a file system or Retrieve a Swagger document from a URL using HTTP or HTTPS in the previous step, a window is displayed in which you can select an operation to invoke in the REST API. Select the required operation and click Finish. The RESTRequest node is automatically configured to use the selected operation.
   • Drag and drop a RESTRequest node from the palette onto a connection between two existing nodes in your message flow. The RESTRequest node is inserted into the flow between the two existing nodes, and the configuration wizard opens, enabling you to configure the new node with the required REST API operation.
3. Configure the remaining properties of your RESTRequest node.
   For more information, see RESTRequest node.
4. Configure the security credentials for interacting with the REST API, by using the mqsisetdbparms command command.
   For more information, see Configuring security credentials for connecting to a REST API.