An 'API key expired' Error Doesn't Always Mean Expired. Check Which Key Is Actually Sent Before You Renew It
A 400 with API_KEY_INVALID from the Gemini API cannot tell you whether the key expired or something else is wrong. A small diagnostic script checks env-var precedence and stray quotes first, run here against dummy keys.
gemini-2.5-flash Can Return a 404 'no longer available' While the Docs Still List No Shutdown Date
The shutdown date for gemini-2.5-flash is blank in the official deprecation table, yet 404 reports have been circulating since July. Here is why reading that column as a safety margin misleads you, and how to check your own keys.
Retrying a Retired Model Never Showed Up in Success Latency
With the image generation models shutting down soon, I rebuilt a mock server to see what my retry layer actually does when it hits a retired model ID. The damage landed in wall time and queue wait, and never touched the metric I was watching.
Closing the Failures That Never Throw: Normalizing Gemini API Responses into a Discriminated Union
An HTTP 200 with an empty body will never reach your catch block. Here is how I normalize finishReason and blockReason into a discriminated union, and let a never check turn missed cases into compile errors.
Fixing Gemini API 'This Model Is Overloaded' — Retry Strategy and Timeout Patterns
Practical fixes for Gemini API overload errors, timeouts, and slow responses. Includes production-ready exponential backoff, model fallback patterns, and rate limiting code you can drop into your project today.
Gemini API FAILED_PRECONDITION Error: Case-by-Case Diagnosis and Fixes
FAILED_PRECONDITION in Gemini API means 'the current system state doesn't allow this operation.' Learn to diagnose and fix all common causes: billing setup, API enablement, context cache expiry, and model access restrictions.