Calling an API

When you have a selected a Plan and you begin coding your application, you must retrieve the operation URL to call the API.

To retrieve the operation URL, complete the following steps:

1. Click API Products, then select a product.
2. Click the API that you want to work with.
   The API overview page opens.
3. Select the operation you need and then copy the endpoint.
   This is the URL that the application calls, and its structure is defined:

   Type of API	URL
   REST APIs	https://host/org/catalog/api/operation
   SOAP APIs	https://host/org/catalog/api for all operations in the WSDL.

   where:

   • host is the fully qualified host name of your gateway cluster.
   • org is the URL path of your organization.
   • catalog is the name of your Catalog.
   • api is the name of your API.
   • operation is the URL path of your operation.
4. Take note of any parameters, the request body, and the response body. Code your application to create the expected requests and handle the expected responses.

Depending on the Identify your application using setting for the API, you might have to provide a client ID, or client ID and client secret. To do this, complete the following steps:

5. To find the client ID, complete the following steps:
   1. Click Apps, then click the application name that you want to work with.
   2. Select the Show check box for Client ID.
      The client ID is displayed.
   3. Provide the client ID with the header parameter &client_id=
      For example, the URL used in the API might be:

      https://host/org/catalog/api/quote?loanAmount=20000

      but when you call it with a client ID of 1234, change the URL to:

      https://host/org/catalog/api/quote?loanAmount=20000&client_id=1234

      Note: A client ID is generated automatically by API Connect when you register an application. However, if you specify a customized client ID, by using the CLI or REST API, then the length must not exceed 512 bytes, otherwise the gateway will reject the API request and return a 401 error.
6. The client secret is produced when you register an application. Provide the client secret with the query parameter &client_secret=. If you did not note the client secret when you registered the application, you must reset it; for information, see Managing applications.

The client ID, or client ID and secret can be logged along with the URL. Web servers usually log the URL in their access logs, which would give away the client secret. If you do not want to expose your client ID or secret in the URL, complete the following steps.

7. For the client ID, set the header, X-IBM-Client-Id, as part of the HTTP message that the application sends when it calls the API.
   An example URL statement might be:

   curl --header "X-IBM-Client-Id: 1234" https://host/org/catalog/api/quote?loanAmount=20000

   Note: A client ID is generated automatically by API Connect when you register an application. However, if you specify a customized client ID, by using the CLI or REST API, then the length must not exceed 512 bytes, otherwise the gateway will reject the API request and return a 401 error.
8. For the client secret, set the header, X-IBM-Client-Secret, as part of the HTTP message that the application sends when it calls the API.
   For example, the URL would be:

   https://host/org/catalog/api/quote?loanAmount=20000

   and set the following HTTP headers:

   X-IBM-Client-Id=1234
   X-IBM-Client-Secret=ABCD