Power Platform Community Forum Thread Details

Hi Community,

I would appreciate some help or guidance in this.

I am trying to understand that the application authenticates to Oracle SME (Fusion Cloud) REST APIs using JSON Web Token (JWT) based authentication, as defined by RS256.

Using Cloud function generated Json Web Token and it's working fine while testing with in Postman API call to Oracle end point using Authorization as Bearer<token>.

While Integrating the JWT in Power automate using Cloud function URL Json Web Token got generated and while using generated JWT as Authorization Bearer<token> in HHTP call to Oracle Fusion Endpoint it's failing as Unauthorized.

Within Power Automate, the JWT generation and API call will be implemented as follows:
1.The private key required for signing the JWT will be securely stored as Secret Manager.
2. Generate JWT Token Using Cloud function(Compose/Custom Action):
Build the JWT Header (JSON → Base64URL encode).
Build the JWT Payload with iss, prn, sub, iat, exp (JSON → Base64URL encode).
Sign the concatenated string with the private key using RS256 → produce the Signature.
Final token: base64url(header).base64url(payload).base64url(signature).
3.Use an HTTP action in Power Automate to call required endpoint:
Method: GET / POST (as required by the Oracle endpoint)
URL: https://<oracle-host>/path/to/api/endpoint
Headers:
Authorization: Bearer <JWT_TOKEN>
Content-Type: application/json.

Could you please review the above approach and confirm if this aligns with the recommended pattern? Additionally, I would appreciate any suggestions, best practices, or considerations—especially regarding JWT generation within Power Automate —that we should incorporate.

Thank you

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Building flows