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AG Kit
github.comrepo

AG Kit

AG Kit is an open-source Antigravity-first agent engineering toolkit that installs a `.agents/` workspace contract of rules, skills, specialist agents, workflows, persistent memory, and MCP configuration for Google's Antigravity coding-agent runtime. It ships a native PreToolUse safety hook that blocks destructive commands (root-filesystem deletion, drive formatting, raw-disk overwrites) without replacing Antigravity's own permissions or sandboxing, plus a CLI (`ag-kit init`/`update`/`rollback`) with merge-aware, backed-up updates and SemVer-versioned, drift-checked toolkit manifests.

TL;DR A versioned, hook-protected `.agents/` toolkit (rules, skills, agents, MCP sync) built for Google Antigravity's coding-agent runtime.
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How to use it

Install per-project without a global install, or globally:

npx @vudovn/ag-kit init
npm install -g @vudovn/ag-kit
ag-kit init

Requirements the page states: Node.js 22+ for the Antigravity integration checks (the published CLI itself runs on Node.js 18+), Python 3.10+ for validators/utility scripts, Git, and a trusted Google Antigravity workspace. Open the repo as a trusted workspace, then confirm /plan, /coordinate, /orchestrate are discovered and skills load from .agents/skills/.

Verify the safety hook with a mocked payload — do not run a real destructive command:

printf '%s' '{"tool_args":{"CommandLine":"rm -rf /"}}' \
  | node .agents/hooks/validate-tool-call.mjs

It must exit non-zero and print BLOCKED by AG Kit. The hook is registered in .agents/hooks.json as a PreToolUse matcher on run_command with a 10s timeout; set "enabled": false and reopen the workspace to disable it for diagnosis.

Doctor/validators: npm run check:agents, npm run check:antigravity (read-only), npm run test:antigravity. Note the default MCP example ships YOUR_API_KEY, so check:antigravity warns until placeholders are resolved; --strict mode (node .agents/hooks/antigravity-doctor.mjs --strict) only passes after that.

Update flow is merge-aware and backed up:

ag-kit update --dry-run
ag-kit update
ag-kit update --strategy replace
ag-kit rollback

Metadata lives in .agents/.ag-kit/; backups in .ag-kit-backups/ outside the toolkit tree. MCP sync is explicit — inspect with sync-mcp.mjs --check/--print, apply with --apply --target suite|cli; existing servers are preserved unless --force. An optional Antigravity plugin can be built (npm run build:antigravity-plugin) into dist/antigravity-plugin/ with a PLUGIN_CONTENTS.json of SHA-256 entries and installed via agy plugin install ./dist/antigravity-plugin.

Limits

  • .gitignore gotcha: do not add .agents/ to .gitignore or Antigravity won't index rules/skills/workflows; use .git/info/exclude to keep it local without breaking discovery.
  • Runtime guarantee is Antigravity-only. Other tools may read the Markdown components, but behavior outside Antigravity is explicitly not covered by the production compatibility guarantee.
  • Read MIGRATION.md before upgrading an existing install to this Antigravity-native release.
  • The repo page carries a Solana-style contract address (CA: Gjpatn3d24dCRhUng7F37K6xJba4R8SDBC18xs1Apump) alongside the MIT license — worth noting given it sits on an otherwise engineering-focused toolkit.

Organisations named here

  • Google
  • vudovn

Technologies named here

  • AG Kit
  • Google Antigravity
  • Model Context Protocol
  • agy
  • Node.js
  • Python

Techniques named here

  • Native safety hook
  • Merge-aware updates
  • SemVer contract with manifest/lockfile

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