When responseSchema Can't Do $ref: Handling Recursive Schemas in Production with responseJsonSchema
Gemini's responseSchema is an OpenAPI subset with no $ref or $defs, so it can't express shared definitions or recursion. Here's how I moved to responseJsonSchema to reuse localized fields and handle a recursive category tree in production.
When a Whole Chapter Vanished From My Long-PDF Summary — Field Notes on Auditing Coverage
Chapter-wise summarize-then-merge works well on long PDFs, but a lost extraction or a merge step can drop an entire chapter while the pipeline finishes without a single error. This walks through catching those silent drops with one number—coverage—and re-running only the chapters that fell out.
My ADK Assistant Quietly Forgot a Deadline — Catching Compaction Memory Loss With a Recall Probe
Compacting conversation history in Google ADK with Gemini lowers cost, but it also erodes what your assistant remembers — silently. Here is how I built a recall probe to measure that loss, compared three compaction strategies against the same ledger, and stopped trading memory for tokens.
Setting a Token Budget Per Free User: Balancing AdMob Revenue Against AI Feature Cost
Rate limits protect requests per minute. They do nothing for the invoice that arrives at the end of the month. Here is how I derive a per-user token budget from ad revenue, keep the ledger inside a single call wrapper, degrade gracefully at a soft cap, and detect abuse with one concentration ratio.
Google Sheets API × Gemini API: A Python Data Pipeline — No Apps Script Required
Learn how to build a fully Python-based pipeline that reads data from Google Sheets, processes it with Gemini API, and writes results back — without touching Apps Script. Covers service account auth, structured output, and rate limit handling.
Being Able to Say Later Where a User's Data Was Processed — Region-Pinned Gemini (Vertex AI) Clients and a Residency Policy Gate
The default global endpoint is convenient, but it leaves you unable to explain where an EU user's data was processed. Here is a design built from three parts—a region-pinned Vertex AI client, a policy gate that forbids implicit global fallback, and a call ledger—with working code and measured latency.
Catch Near-Duplicate Posts Before You Publish — a Topic-Cannibalization Gate with Gemini Embeddings
Once a blog passes a few hundred posts, new articles start cannibalizing old ones in search. This walks through a pre-publish gate that embeds each post's meaning with gemini-embedding-2 and blocks drafts that sit too close to something you already wrote — with runnable code and how to pick the thresholds.
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.
Guarding Gemini API Responses in CI: Snapshot and Semantic Regression Testing
Defend non-deterministic Gemini API responses with pytest snapshots plus embedding-based semantic regression detection: record/replay CI, a weekly live smoke that keeps cassettes honest, per-field drift reporting, threshold calibration, and update governance — all in working code.
Mixing Text and Images in One File Search Skewed My Results Toward Images — Rebalancing by Modality After Retrieval
When you put text and images in a single File Search store with gemini-embedding-2, results can quietly skew toward one modality. Here is how to measure that skew and even it out after retrieval, using per-modality normalization and quota-based merging — with working code.
A Promotion Gate So gemini-flash-latest Flipping to 3.5 Flash Doesn't Break Your Pipeline at 3 AM
Floating aliases like gemini-flash-latest swap their target on every GA, quietly shifting the assumptions your unattended automation depends on. Here is a role-to-pinned-ID indirection layer, an acceptance harness that measures four metrics against your own golden set, and threshold-driven promotion and automatic rollback — with working code.
Turning Articles into Audio with the Gemini 3.1 Flash TTS Preview: Splitting Long Text, Stitching It Back, and What It Actually Costs
The Gemini 3.1 Flash TTS preview launched today. Here is a single-narrator pipeline that converts a written article into clean audio, including how to split long text, stitch PCM without ugly seams, keep one voice steady, and estimate the real per-article cost.