Programming Tutorials

  There is a specific, maddening scenario that plagues developers integrating with the Google Ads API. You build an automated reporting tool or a bid management script. You generate your OAuth2 credentials, perform the initial handshake, and everything runs perfectly. Then, exactly 168 hours (7 days) later, your logs turn red. The error message is terse:  invalid_grant . Your refresh token, which is supposed to provide long-term access, has stopped working. You generate a new one, and the cycle repeats a week later. If you are encountering this strict 7-day expiration, your code is likely fine. The issue lies in your Google Cloud Project configuration. This guide details the root cause and provides the configuration changes required to secure a persistent refresh token. The Root Cause: Google Cloud "Testing" Status The behavior you are experiencing is not a bug; it is a security feature enforced by the Google Identity Platform. When you create a new OAuth 2.0 Client ID in the...

  Few things are more frustrating in backend development than an authentication flow that works perfectly in development but fails sporadically in production. If you are integrating the Payoneer API, you have likely encountered the dreaded   invalid_grant   error during the   refresh_token   grant exchange. This error usually results in a hard crash of the integration, requiring manual intervention to re-authenticate the user. This article dissects the root cause of this error—specifically within the context of Payoneer’s strict token rotation policies—and provides production-ready solutions in Node.js and PHP. The Root Cause: Token Rotation and Race Conditions To fix the error, you must understand exactly why Payoneer rejects the request. The  invalid_grant  error code, defined in RFC 6749, is a catch-all for invalid authentication credentials. However, in the context of a refresh flow, it almost always points to  Token Rotation violations . How ...