Antigravity CLI role (Reference implementer)

[!NOTE] This page describes Google Antigravity CLI’s responsibilities in the default reference workflow. The underlying .agent-bus runtime is agent-agnostic and allows assigning the implementer role to other registered agents.

In the default reference workflow, Google Antigravity CLI (agy) fulfills the implementation role:

  • claims an IMPLEMENT or CHANGES_REQUESTED message from .agent-bus/inbox/antigravity/new;
  • edits source code, tests, UI, and build configuration;
  • performs browser, unit, or UI validation when required;
  • runs the agreed checks and records evidence under .agent-bus/evidence/;
  • creates a focused Git commit and reports IMPLEMENTATION_DONE.

Antigravity does not approve its own work and does not merge, tag, push, deploy, or publish. It retains its native Google account authentication and model subscription.

The Plugin Task path uses the canonical Execution Session Runtime. task dispatch validates the resolved command, opens or reuses one Runtime-owned persistent PTY, and records the Task’s non-owning sessionId. After CHANGES_REQUESTED, the next explicit dispatch reuses the same healthy Session and writes the feedback into that PTY context. A Session in exited or failed is reported as a fact and is never retried in a loop. The separate CLI launch command retains its legacy bus-supervised compatibility policy; it is not the Plugin Session Manager.

Session status, bounded output, input, and close are available through the Coordinate Agents MCP Session tools. They operate on the Runtime-owned process only and never type into or control the Codex App Terminal UI.

The executable can be overridden per machine without changing the installed Skill or project defaults:

npx @hogancv/coordinate-agents config set agent.antigravity.command agy-proxy

The project command, if explicitly present, takes precedence over ~/.coordinate-agents/config.json, which takes precedence over the Adapter default agy. launch and Session dispatch check the resolved executable before starting. Spawn failures, non-zero exits, and CLI conversation/runtime failures write structured ERROR/Session facts, preserve bounded output, and stop. They are not automatically retried. Login state is not preflighted; a login/provider error reported by agy is handled as a runtime failure with a bounded stdout/stderr tail.

Permission and sandbox arguments

The built-in antigravity-cli Adapter does not infer a permission mode. Its legacy one-shot path passes configured args and then appends --prompt-interactive <prompt>; a persistent Session starts with --prompt-interactive "" so current agy/agy-proxy parsers receive the required empty initial prompt value, then writes its first instruction through the PTY unless {prompt} is explicitly configured. It does not automatically add --dangerously-skip-permissions or another sandbox-bypass flag. If agy is already configured locally for full permissions, that native setting remains in effect.

If the installed agy --help confirms the explicit flag and the user intentionally wants to use it, configure it outside the installed Skill/Plugin:

npx @hogancv/coordinate-agents@latest config set agent.antigravity.args '["--dangerously-skip-permissions"]'
npx @hogancv/coordinate-agents@latest config list

doctor verifies the executable and version, not the effective provider permission state. Never copy a permission flag from another CLI or version without checking its own help output.