All Articles
Routing Between Local Gemma 4 and the Gemini API Cut My Bill from ¥32,000 to ¥9,000 — A Production Hybrid Router Design
How I cut a ¥32,000/month Gemini API bill to the ¥9,000 range with hybrid inference: routing design, a full Python router, production pitfalls, and how Gemma 4 arriving on the Gemini API in July 2026 changes the decision.
Deleting the Source Isn't Enough — A Ledger Design for Propagating Deletes Through Gemini-Derived Data
When a user deletes their data, the embeddings, caches, and File Search documents you generated from it live on. A provenance ledger written at generation time, per-sink propagation workers, and a verification sweep make deletion actually reach your derived data.
After You Improve the Prompt, How Far Back Do You Regenerate? — Designing a Budget-Bounded Backfill
A prompt improvement only helps future output — thousands of old artifacts stay on the previous generation. This piece covers a budget-bounded backfill: selection scoring, edit-detection hashes, a pre-replacement gate, and a resumable cursor, with working code.
url_context Still Answers When the Fetch Fails — Gating on Retrieval Status Before You Trust It
The url_context tool returns a confident answer even when it failed to fetch the target page. This walks through reading url_retrieval_status from url_context_metadata to build a verification gate, plus a fallback that only finalizes an answer when the source URL was truly read.
Locking Down a Gemini API Key on Servers Whose IP Keeps Changing — Restrictions for Headless Automation
After unrestricted keys started getting blocked, headless server automation whose egress IP changes every run can't cleanly use HTTP referrer, app restrictions, or an IP allowlist. Do you get by with API restrictions alone, funnel egress through a fixed IP, or move server workloads off API keys onto Vertex service-account auth? A decision framework and working code, without taking your pipelines down.
Selling Gemini Gems as Enterprise Prompt Products — Turning Custom Instructions into Monthly Contracts
A complete strategy for indie developers and small studios who want to package and sell Gemini Gems as enterprise prompt products. Covers design framework, pricing, contract models, support operations, and customer success case studies — written from real operating experience.
Getting Artifacts Out of a Managed Agents Sandbox Safely — Scoped Credentials and Egress Design
Gemini API Managed Agents run in a Google-hosted isolated sandbox. Here is the short-lived, least-privilege credential and egress-boundary design I use to return generated artifacts to my own repository safely.
Keeping Unattended Jobs From Failing Silently: A Preflight Gate for Gemini's Platform Changes
Unrestricted API keys are now rejected, the old CLI reached end of life, and the Interactions API is becoming the default entry point. These 2026 platform shifts stop working automation without raising an error. Here is a preflight gate, with runnable code, that catches the failure before the batch runs.
When a Prompt That Worked in AI Studio Quietly Breaks Over the API — Field Notes on Measuring the Difference
A prompt that behaves perfectly in AI Studio returns an empty string or a 404 the moment you call the Gemini API from your own code. Instead of eyeballing the two, here is a small harness that records the config diff plus finish_reason, token usage, and the model name the server actually resolved — so you can isolate the cause by layer.
When Two Triggers Write at Once, Your Gemini Result Quietly Vanishes — A Durable Result Store for Apps Script
Storing Gemini results from several Apps Script triggers loses writes through read-modify-write races and PropertiesService size limits. Build a result store that survives, using LockService, a durable sink, and idempotency keys.
Fire-and-Forget on a Cron That Never Loses a Result: Reclaiming Gemini Background Executions with a Submission Ledger
A design for running the Interactions API's background execution safely from a cron-driven runner. We reserve a row in a ledger by idempotency key before submitting, then reclaim only outstanding handles on the next tick — shown with working code.
Building an AI-Powered Content Site with Gemini API and Astro
Combine Astro Server Endpoints and Content Collections with the Gemini API to add AI summaries, related-article recommendations, and auto-tagging.