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.
Taking stock of Gemini standard API keys before September, across CI, servers, and my own machine
Standard API keys, including restricted ones, stop being accepted during September. Because this changes where keys come from rather than what they say, here is the three-layer inventory I ran across code, deploy settings, and my local machine, plus a dual-path client to switch behind.
Running Streamlit + Gemini as a Production BI Dashboard — Auth, Cost, Caching, Rate Limits, Observability
A design memo for promoting a Streamlit + Gemini data analysis app into a real multi-user internal BI dashboard — authentication, cost optimization, result caching, per-user rate limits, and observability, all from production experience.
Migrating Working Code from AI Studio to Vertex AI: A Solo Developer's Hands-On Walkthrough
What actually changes when you move existing Gemini API code from AI Studio to Vertex AI. Includes side-by-side code diffs for SDK init, auth, and response parsing.
Vertex AI + Gemini Authentication Error Fix: Service Account & ADC Troubleshooting Guide
Struggling with Vertex AI Gemini authentication errors? This guide covers the most common causes—service account misconfiguration and ADC setup issues—with step-by-step solutions to get you unblocked fast.
Gemini Code Assist Outline Stays Empty: Seven Things to Check
Fix Gemini Code Assist Outline not showing suggestions, failing silently, or throwing authentication errors. Full coverage for VS Code and JetBrains—from plugin setup to enterprise IAM configuration.
Gemini API Authentication Errors: Causes and Solutions
Complete guide to diagnosing and fixing Gemini API authentication errors including 401/403 status codes, API key issues, and permissions.