Antigravity-OS

1What it does

A .agent/rules/ governance framework built as nine numbered rule files that interlock into something closer to an operating policy than a style guide: 00-plan-first forces planning before execution, 01-data-contracts pins interface shapes, 02-fail-closed requires explicit failure behavior, 03-sentinel adds watchdog checks, 04-governance assigns decision authority, 05-flight-recorder mandates an audit trail of agent actions, 06-handover defines session-to-session context transfer, 07-telemetry tracks metrics, and 08-economic-safety puts cost and resource boundaries around autonomous runs. Where most packs tell the agent what not to do, this one describes how the agent must account for what it did — the flight-recorder and handover files are the pieces almost nothing else in the ecosystem attempts, and they are what make long autonomous sessions recoverable instead of mysterious.

2When to use it

Reach for it on long-running or semi-autonomous agent sessions — multi-hour refactors, agent-managed migration work, or any setup where the agent operates unattended and a human audits later. The governance/telemetry layer is overkill for interactive pair-programming where you watch every diff land; there the ceremony costs more than the accountability buys. It also suits team environments where the question "why did the agent do that?" needs an answer better than scrolling a transcript — the audit trail is the feature, not a byproduct. Skip it entirely on small repos or when you want a minimal always-on ruleset; nine files is the heaviest pack in this directory and the benefit compounds only when sessions are long enough to need recovery.

3How to get started

Clone the repository and copy .agent/rules/ into your project root — the numbered filenames matter because rules load in lexical order and 00-plan-first is designed to shape everything downstream. Adopt it in stages rather than all nine at once: start with 00, 02, and 05 (plan-first, fail-closed, flight-recorder), run a real task, and read the audit trail it produces before layering on governance and telemetry. The framework assumes your workflow tolerates structured agent output — if your agent's answers become bureaucratic, the telemetry and governance layers are the first files to relax, not the fail-closed one.

4Configuration

Everything lives in the rule files' frontmatter and prose — there is no tooling layer to configure. The flight-recorder rules expect a writable location for the agent's action log; check the file's own text for where it directs output and point it somewhere your gitignore covers if the logs should stay local. 08-economic-safety is the file most worth editing to your own thresholds — it expresses budget boundaries as policy rather than hard limits, so the numbers are guidance you tune, not constants you obey. If you run both Windsurf and Antigravity on the same project, note this pack targets .agent/rules/ only.

5Things to know

• The framework is a design pattern as much as a rules pack — teams fork it for the idea (numbered, ordered, auditable rules) more often than they adopt all nine files verbatim.
• Fail-closed is the load-bearing rule: the framework assumes the agent reports failure explicitly instead of improvising around it, which is what makes the audit trail trustworthy.
• Nine always-on rule files consume real context on every run — on small tasks the overhead is the dominant cost; gate by .agent/rules/ presence per project rather than installing globally.
• Pairs naturally with a thin conventions pack (commit/PR formats) underneath — this repo deliberately skips style-level rules. - Versioning is the maintainer's lever — the numbered files evolve on the repo's own cadence, so pin a commit when you adopt and review the diff before pulling updates into a production ruleset.
• It is the philosophical opposite of a thin guard pack: thin packs cap what the agent may do; this one specifies what the agent must record. Projects that need both usually run a thin pack at workspace level and this at the org/global level.

6Related on the map

References

• .agent/rules directory
• Antigravity rules documentation