How to Validate an Externally-generated OAuth token

Google Cloud Apigee
3

Thanks Srinandan for your response.

Step1: I created the “AssignMessage” and “OAuthV2” policy in the response step of the pre flow.
Step2: Created “OAuthV2” for token validation

Verify OAuth v2.0 Access Token
VerifyAccessToken

Also I followed steps in http://docs.apigee.com/developer-services/content/import-existing-consumer-keys-and-secrets
But out of 2 steps, I was able to create consumer keys-and-secrets but failed in Step 2 associate keys-and-secrets with product. And I am getting 404 error here (I verified that all the param looks fine in the request)

Then I try to access the proxies. I was able to get the token from the Internal OAuth server, but failed during the step2
“faultstring”: “Invalid Access Token”