Call SAP Conversational AI API with OAuth (Postman)

Create a new collection by again clicking New+, and this time selecting Environment.

Call the collection OAuthCAIAPI, and click Create.

Click New+ > Request.

Enter start as the name, select the OAuthCAIAPI collection, and then click Save to OAuthCAIAPI.

To the request, add the URL:

https://postman-echo.com/get

This is a dummy URL and let’s us perform a script before calling any other APIs.

To the request, add the following to the Pre-request Script:

if (pm.environment.get("oauthtoken") != null) {
  postman.setNextRequest("request")
  pm.environment.set("retry", "true");
  console.log("HAVE TOKEN")
}

This script checks if there already exists an OAuth token. If a token exists, we skip the call to get a token and we create a flag that indicate that if the API call fails we want to try again (after we retrieve a new token, for example, because it has expired).

Click Save.

Click New+ > Request.

Enter get-oauth-credentials as the name, select the OAuthCAIAPI collection, and then click Save to OAuthCAIAPI.

To the request, add the URL:

https://sapcai-community.authentication.eu10.hana.ondemand.com/oauth/token

To the request, under Authorization, set the type Basic Auth.

Set the Username to {{clientid}}.

Set the Password to {{secret}}.

This will take the credentials from the environment variables.

To the request, add a body.

Set the type to x-www-form-urlencoded.

Set the key to grant_type and the value to client_credentials.

To the request, add the following to the Pre-request Script:

pm.environment.set("retry", "false");

This indicates that we have retrieved a new OAuth token, and once we try the API call, we do not want to retry (with a newer OAuth token).

To the request, add the following to the Tests:

bodyData = JSON.parse(responseBody);
token = bodyData.access_token;
pm.environment.set("oauthtoken",token);
console.log("GOT TOKEN");

This retrieves the token and stores in the environment, for use with the API call.

Click Save.

Click New+ > Request.

Enter request as the name, select the OAuthCAIAPI collection, and then click Save to OAuthCAIAPI.

To the request, add the URL:

https://api.cai.tools.sap/train/v2/request

To the request, under Authorization, set the type Bearer Token.

Set the Token to {{oauthtoken}}.

This will take the token from the environment, where we stored it in the previous step.

To the request, add the following header:

This will indicate to the API which chatbot to query.

To the request, add a body.

Set the type to raw, and add the following body:

{   
      "text" : "Hi"
}

This is the utterance to send to the NLP, and should return the greeting intent.

To the request, add the following to the Tests:

if (pm.environment.get("retry")=="true" && pm.response.code ==401) {
    postman.setNextRequest("get-oath-credentials")
}

// Check if the request was successful (OAuth token was OK)
pm.test("Request succeeded", function () {
    pm.response.to.have.status(200);
});

// Test if the correct intent was returned
pm.test("Is intent correct", function () {
    var jsonData = pm.response.json();
    pm.expect(jsonData.results.intents[0].slug).to.eql("greetings");
});

This code starts by checking if we had an authentication error and whether we want to retry in such a case – if so, we tell Postman to retrieve the OAuth token.

After that, we add some standard tests, first that the call worked, and then whether the correct intent was returned. These are optional.

Click Save.