The Built-in Guide Skill Is Only Advice — Pair It With a Gate That Mechanically Rejects Antigravity's Output
The v2.2.1 built-in Guide skill raises how often the agent complies, but it is still probabilistic advice. Here is the design for a deterministic gate that reliably stops the violations that slip through, with working code and measured results.
When Parallel Sub-Agents Fight Over One API's Rate Limit: A Shared Token Bucket That Caps the Aggregate
Run Antigravity 2.0 dynamic sub-agents in parallel and each one hits the same external API independently, pushing the aggregate rate over the limit and triggering cascades of 429s. Here is a shared token bucket that caps the aggregate proactively, with working code through a Redis version.
When Your Antigravity Agent Opens a PR That Just Says "Update files" — and a Gate That Forces a Reviewable Summary
Pull requests opened automatically by an Antigravity agent tend to carry empty descriptions like "Update files." Here is a validation gate, with working code, that estimates risk from the diff and rejects vacuous descriptions so a human can actually review them.
When Your Antigravity-Written Tests Only Look Green: Measuring Effectiveness with Mutation Testing
Tests written by an Antigravity agent can pass and still fail to catch the bug that matters. Here is how to measure their real effectiveness with mutation testing and only adopt tests after they kill the surviving mutants — with working code.
A Review Gate Design for Safely Folding Parallel Agents' Diffs into One Branch
Antigravity 2.0 made running multiple agents in parallel practical, but verifying each agent's output and integrating it into one branch is left to you. Here is how to build a diff-level review gate in stages, with judgment criteria and scripts.
It Did Things I Never Asked For — Binding an Agent's Task Scope With a Contract
Ask it to fix a button color and you get a refactor, renames, and a dependency bump too. This is a scope problem, not a permission one. Here is a contract that stops at the scope boundary and asks.
Treating Built-in Guide Skills as Design Assets, Not Throwaway Prompts
Antigravity v2.2.1 added built-in Guide skills. Here is a concrete structure and set of judgment calls for running them as version-controlled, shared design assets instead of one-off instructions.
The Day the Article I Asked It to Format Became the Agent's Instructions
When you run an unattended content-formatting pipeline with Antigravity CLI, instruction-like text buried in the file you are processing can hijack the agent. Here is how I separate the instruction channel from the data channel and add an output-scope acceptance gate to reject anything out of bounds.
What Tripped Me Up First When Antigravity 2.0 Split the IDE and the Agent Into Separate Apps
Antigravity 2.0's modular layout splits the IDE and the chat-style agent into two separate apps. Here is the moment their file states drifted apart on me, and the save discipline I now use to keep a single source of truth.
Designing MCP Tool Output So It Doesn't Flood Your Agent's Context
When a custom MCP server returns large results in one shot, your Antigravity agent quietly degrades. Field projection, pagination, resource_link, and an output budget keep context from overflowing — shown with concrete TypeScript and measured numbers.
Before a Major Update Silently Breaks Your Overnight Automation — Designing a Staged-Adoption Canary Gate
After a major update dropped my unattended run success rate from about 98% to 63% overnight, I built a staged-adoption gate that freezes the working setup, verifies a new version against a golden output in an isolated profile, and only then adopts it. Here is the design with bash and Python.
Combining All Four Antigravity Surfaces in One Project — Up to Running Your Own SDK Agent
How to split a single project across Antigravity 2.0, CLI, IDE, and SDK, and how to bridge between them — from diverging on design to converging on production, all the way to running a small custom agent with the Python SDK, with implementation included.