Antigravity Support

Status: native hook support plus sidecar policy coverage.

Antigravity documents JSON hooks in hooks.json under a customization directory such as workspace .agents/ or ~/.gemini/config/. Gensee supports that contract with gensee setup antigravity and gensee hook antigravity.

The installed Antigravity desktop chat surface may not show a /hooks slash command. That does not mean hooks are unavailable; the supported setup path is the documented hooks.json file.

Setup

Build or install gensee, then configure global Antigravity hooks:

cargo build -p gensee-crate-cli
GENSEE_HOME="$PWD/.gensee-dev" ./target/debug/gensee setup antigravity

By default, setup writes ~/.gemini/config/hooks.json. For a custom binary or workspace-local Antigravity hook file:

./target/debug/gensee setup antigravity \
  --gensee-home "$PWD/.gensee-dev" \
  --hooks "/path/to/workspace/.agents/hooks.json" \
  --bin "$PWD/target/debug/gensee"

Restart Antigravity after changing hook settings.

Prefer the global hook file for local desktop use so every Antigravity project gets the same Gensee policy bridge. Use workspace-local .agents/hooks.json only when a project intentionally needs a different hook setup. Avoid keeping multiple .agents/hooks.json files under one selected workspace tree unless you intentionally want Antigravity to load more than one hook definition; otherwise repeated tool attempts can show duplicate audit rows.

Installed Hooks

Gensee installs a gensee-policy hook with:

• PreToolUse for inline allow/ask/deny policy decisions.
• PostToolUse for recording completed tool activity and write-time artifact observations.
• PreInvocation for memory, skill, plugin, and rule integrity checks before the next model call.

The generated command is equivalent to:

GENSEE_HOME=/absolute/gensee-home /absolute/path/to/gensee hook antigravity

Coverage

Gensee parses Antigravity's documented toolCall payloads:

• run_command shell commands.
• file and directory tools such as view_file, write_to_file, replace_file_content, multi_replace_file_content, list_dir, and find_by_name.
• conversationId, workspacePaths, transcriptPath, stepIdx, and error metadata for timeline attribution.

The hook response uses Antigravity's native top-level schema:

{"decision":"ask","reason":"Requires review"}

PreInvocation poison notices are returned as Antigravity injectSteps with an ephemeral security message.

Policy Coverage

The default policy recognizes Antigravity customizations under .agents/:

• .agents/hooks.json and ~/.gemini/config/hooks.json are persistence/control-plane files.
• .agents/skills/, .agents/plugins/, and .agents/rules/ are instruction artifacts.
• Antigravity MCP and sidecar configuration under ~/.gemini/config are persistence/control-plane paths.
• Antigravity state under ~/.gemini/antigravity is classified as control-plane state where appropriate.

You can still run gensee watch --workspace <repo> beside Antigravity for sidecar filesystem audit, and use gensee run -- <antigravity command> when a runnable command surface is available and you want managed launch controls.