Reverse-Engineering Empty Gemini API Responses with finish_reason — Triage, Retry Classification, and Monitoring
An empty response.text has three distinct failure layers — candidates, prompt_feedback, and finish_reason. Production code for detecting thinking-token starvation, classifying what is worth retrying, and monitoring your empty-response rate.
Gemini Live API Audio Sounds Sped Up — Fixing the Sample Rate Mismatch
When Gemini Live API responses sound high-pitched and sped up, or come back full of noise, the cause is almost always that the 24kHz output is being played at a different sample rate. Here are the concrete fixes for both the browser and iOS.
Why Firebase AI Logic Returns 403 When Calling Gemini from iOS — And How to Fix It
Firebase AI Logic (formerly Vertex AI in Firebase) often returns 403 PERMISSION_DENIED when calling Gemini from an iOS app. Here is how to isolate the three real causes — App Check enforcement, disabled APIs, and missing Blaze billing — based on hands-on device testing.
Empty Output but finish_reason Is MAX_TOKENS on Gemini 2.5/3: Cause and Fix
Your prompt is just a few lines, yet a low maxOutputTokens on gemini-2.5-flash returns empty text with finish_reason MAX_TOKENS. The culprit is thinking tokens. Here are three fixes with working code.
Why Gemini API Throws 'Unsupported MIME type' and How to Fix It
The 'Unsupported MIME type' error from the Gemini API has three distinct causes: a misspelled MIME string, an octet-stream upload, and a genuinely unsupported format. Here is how to tell them apart with code that actually works.
Why Gemini 2.5 Pro Rejects thinkingBudget: 0 (and How to Fix It)
Setting thinkingBudget to 0 on Gemini 2.5 Pro returns a 400 INVALID_ARGUMENT error. Here is why the per-model thinking budget ranges differ, how to minimize thinking on Pro the right way, and when to switch to Flash, with Python and JavaScript examples.
Why HTTP Referrer Restrictions on Your Gemini API Key Cause 403 Errors in Production
Walks through why a Gemini API key with HTTP referrer restrictions can suddenly return 403 PERMISSION_DENIED in production. Covers the exact referrer string format, SDK behavior differences, how to safely route around the limitation with a tiny edge proxy, and how it differs from the CORS error you hit when calling straight from the browser.
Why per-turn generationConfig is ignored in Gemini API chat sessions
If you pass a different generationConfig (temperature, max_output_tokens, response_schema) to each send_message in a google-genai chat session and the behavior never changes, this walkthrough shows what is actually happening, why the SDK is designed that way, and three workarounds we use in production for review-summary and reply-draft pipelines.
Fixing NotebookLM Audio Overview When It Generates in the Wrong Language or Stalls Mid-Way
Five concrete causes and fixes for when NotebookLM's Audio Overview ignores your source language, freezes on the progress bar, or cuts off mid-playback — written from hands-on use during app review analysis.
Why Gemini API Streaming Drops on iOS After Backgrounding — and How to Fix It
When your iOS app receives a streaming response from Gemini API and the user briefly switches to another app, the stream often goes silent forever. Here's how URLSession actually treats long-lived HTTP, and the smallest change that brings reliability back.
When gemini-2.5-flash-image Ignores Your Reference Image — Diagnosing Why Nano Banana Returns a Totally Different Picture
A field-tested triage order for the situations where gemini-2.5-flash-image (Nano Banana) silently ignores your reference image, swaps the subject, or refuses to honor your edit instructions. Covers parts ordering, response_modalities, image size, and chat-session pitfalls with runnable code.
Why Your Gemini File API Uploads Vanish After 48 Hours — and How to Code Around It
Gemini File API resources are auto-deleted 48 hours after upload. Here is how to recognize the failure, why it happens, and concrete patterns for re-uploading, falling back to inline data, and managing expiration safely.