Antigravity CLI Delegate

中文 · Skill · Host setup

A small agent skill and event-driven runner for delegating bounded work to Gemini Flash through Google Antigravity CLI. The caller sends a short brief, receives live tool progress, and accepts a compact final result. No status polling or supervisor model.

• Defaults to the newest listed Gemini Flash >= 3.8, Medium. High is opt-in. Exact model requests win; explicit Claude Opus Thinking is also supported.

• One pending MCP call, standard progress notifications, one terminal response.

• Prompts go through stdin; raw events and stderr stay in private local files.

• Default final summary: 2,400 characters plus an explicit truncation marker and evidence paths. Tool arguments, outputs, and reasoning are excluded from progress.

• CLI failure, invalid results, cancellation, and deadlines fail closed. No automatic retries.

This is a community project, not an official Google or OpenAI product. It uses agy, not the gemini CLI. An existing authenticated Antigravity account is required.

Install

Requires Node 22+, macOS or Linux, and an authenticated agy installation. Tested against agy 1.2.0; the runner checks capabilities and available models on each run.

git clone https://github.com/WangZhuo2015/antigravity-cli-delegate.git
cd antigravity-cli-delegate
npm ci --ignore-scripts

For Codex skill discovery, link the repository to your skills directory. If the destination already exists, preserve it before replacing it:

mkdir -p "${CODEX_HOME:-$HOME/.codex}/skills"
ln -s "$PWD" "${CODEX_HOME:-$HOME/.codex}/skills/antigravity-cli-delegate"

Register the MCP server for the no-polling workflow:

codex mcp add antigravity-delegate -- node "$PWD/scripts/mcp.mjs"

Set tool_timeout_sec = 660 in the resulting [mcp_servers.antigravity-delegate] configuration table for the default 600-second runner deadline. Restart the host session if needed. Other MCP hosts can run the same stdio command; see host setup for timeouts and progress tokens. The host controls whether progress is displayed and whether other work can run concurrently.

Related MCP server: cursor-agent-bridge

Use

Ask your agent:

Use $antigravity-cli-delegate to review src/parser.mjs for the failing empty-input case. Read only that module and its test. Report the cause with line references; do not edit files.

Or call the MCP delegate tool directly:

{
  "cwd": "/absolute/project",
  "task": "Goal: fix the empty-input case. Scope: src/parser.mjs and test/parser.test.mjs only; preserve unrelated changes. Check: node --test test/parser.test.mjs. Report: changed files and check results.",
  "mode": "accept-edits"
}

The default mode is plan with --sandbox. Use accept-edits only when the user has authorized those edits. These settings and prompt constraints are not a filesystem allowlist; use an isolated workspace when stronger containment is needed. The caller still checks the diff and acceptance evidence. SUCCESS only means the CLI completed.

The same runner works without MCP dependencies from a foreground terminal:

node scripts/run.mjs --cwd /absolute/project --task-file /absolute/brief.txt

Optional flags: --effort high, --model EXACT_LISTED_ID, --mode accept-edits, --timeout-seconds 600, --max-summary-chars 2400. Use AGY_BIN for a custom CLI path.

How it avoids caller overhead

short brief → one delegate call → agy stdin / NDJSON event stream
                               ↘ tool-state notifications → host UI
                                ↘ complete local evidence → disk
                                 ↘ compact final result → caller model

The runner waits on pipe and process events. Its only timers are a deadline and termination escalation; there are no heartbeat, sleep/check, or polling loops. A host that offers only polling shell sessions cannot provide no-polling background execution; use MCP or a single foreground call instead. There is no background job queue or durable reconnect/resume mechanism: closing the MCP transport cancels active work.

The rewritten skill is roughly 61% shorter by word count than its original local version. This is not a measured token-cost reduction. Actual caller usage depends on the host, brief, result length, and verification. The usage field is the worker's usage. The runtime also avoids returning repeated preflight output to the caller.

Verify and contribute

npm test
node scripts/smoke.mjs

npm test is offline and uses a protocol double. The second command is an explicit live check using your authenticated account: it asks Gemini to read a temporary fixture, checks the answer and unchanged files, and receives progress through the official MCP client. It is excluded from CI and may consume account quota. Test logs contain local workspace data; review them before sharing and remove them when no longer needed.

Tests cover model routing, streaming before completion, duplicate filtering, bounded summaries, private evidence, stdin quoting, unsuccessful status/exit, broken streams, timeouts, and cancellation. Contributions should preserve these observable behaviors. Run npm test before submitting changes; do not include credentials or local run logs.

License

MIT. Protocol references: Antigravity headless mode and MCP progress.