Question & Answer
Question
Issue
When testing the REST connection in Apptio Datalink, the connection test fails with the following error message:
Error Code: 400
Error: Error message received from HTTP Server
Message: Bad Request Message from server
The same request works successfully in Postman, the Datalink connection fails.
Cause
The failure occurs because the Authorization header and other required HTTP headers were not properly configured in Apptio Datalink.
In Postman, the Authorization token is automatically included through the Basic Auth setup, but in Datalink, these values must be manually entered under REST Headers.
Answer
Obtain Authorization Token
1. Open the Postman request that works correctly.
2. Go to the Authorization tab.
3. Note the Authorization header value that Postman generates automatically (as shown below).
Authorization: Basic <token_value>
Configure Apptio Datalink Connection
1.Go to Apptio Datalink → Connections → Source System.
2.Select REST Service HTTP Client Connection and verify the connection credentials are correct.
3.Under Authentication Type, choose Basic.
4.Set the following parameters:
REST URL: https://<base_url>
URI Path: /api/public/v1/models/<model_id>/intersections/
Add Required REST Headers
Under the REST Headers section, add the following keys and values:
| Key | Value |
|---|---|
| Authorization | <Authorization token from Postman> |
| Accept | */* |
| Content-Type | application/json |
Test the Connection
1.Click Test Credentials or Test API in Datalink.
2.The test should return a successful response.
If the test still fails:
1.Double-check the Authorization token for any trailing spaces.
2.Verify the REST URL and URI path are correctly formatted.
3.Ensure the HTTP Method (GET/POST) matches what’s used in Postman.
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Document Information
Modified date:
05 May 2026
UID
ibm17249961