The Day /models Returns 200 but generateContent Returns 403 — Decide Your Triage Order Before It Happens
A triage order for the case where listing models succeeds with 200 but generation fails with 403 permission_denied. Includes a small diagnostic script that checks key, project, and billing in turn, why you should not retry a 403, and how to assemble what support needs.
When Your config Raises "Extra inputs are not permitted", Check the Spelling of Every Key
If a google-genai call fails with a pydantic ValidationError (extra_forbidden) the moment you pass a config, it is almost always a one-letter typo. Here is the output I reproduced, a small function that checks keys before the call, and how to tell why response.text came back as None.
Free Tier Shows Up, but You Get a 429 With `limit: 0` — What to Check in the First Hour of a New Gemini API Project
A new Gemini API project says Free tier, yet the very first call returns 429 with limit: 0. Here is the order I check things in, how to read the error body, and a 40-line script that tests models one by one.
Gemini CLI Kept Saying 'API key not valid' After I Gave It a New Key — It Was Reading an Old One From a Third Place
I switched Gemini CLI from Google login to a paid API key, and the 400 'API key not valid' error would not go away. The key can come from four places — the shell, a project .env, a home .env, and settings.json — and a short script that lights them up in order narrows the cause to one.
When the Sheets AI Function Won't Generate, Suspect the File's Location Before the Limit
If Generate and insert stays greyed out in Google Sheets, don't assume you hit the 24-hour cap. Spreadsheets opened through Dropbox, Box or Egnyte can't generate at all. Here's the order I check things in now.
I edited the Drive doc, asked Gemini again, and it quoted the old sentence back
When Gemini answers from an outdated version of a Drive file, the file usually isn't the problem — the conversation is. Here's how sources stay attached for the whole conversation, why you can't remove one mid-thread, and what to do about partial reads.
When a New Gemini Feature Hasn't Reached Your Workspace, Here's How to Tell Waiting From Broken
A step-by-step way to decide whether a missing Gemini feature in Google Workspace is still rolling out or actually misconfigured, using release tracks and rollout pace, plus a small Apps Script ledger that does the counting for you.
After generated_images Disappeared: Three Branches Between the Response and a Saved File
Once you switch to generate_content, the line that breaks is usually the save. Here are the three branches on the response side - zero image parts, a shifting image count, and picking the extension - plus a receiver function you can drop in.
LM Studio 'Failed to Load Model' for Gemma 4 MLX — A 4-Bucket Diagnostic for Apple Silicon
When LM Studio refuses to load mlx-community/gemma-4-26b-a4b-it-4bit with a red 'Failed to load model' dialog, the cause is almost always one of four buckets. Here's how to triage them on an Apple Silicon Mac in under thirty minutes.
When responseSchema enum returns unexpected values — debugging Gemini API
Why Gemini API sometimes returns values outside the enum you defined in responseSchema, and the three-layer workaround I use in production for my wallpaper app classification pipeline.
Gemini API Streaming Works Locally but Buffers in Production — Fixing Cloud Run, Vercel, and Cloudflare
Streaming responses flow token-by-token in local dev, then arrive as one big blob in production. A walkthrough of the five most common causes — Cloud Run timeouts, Vercel runtime mismatch, Cloudflare Workers proxying, server-side text() pitfalls, and client-side decoding — with the fixes I use on my own sites.
Diagnosing INVALID_ARGUMENT Errors in Gemini API Batch Image Analysis
When using the Gemini API to analyze multiple images at once, INVALID_ARGUMENT errors can be surprisingly hard to diagnose. This guide covers the three root causes—MIME type mismatches, inline data size limits, and contents structure errors—with code to fix each one.