This Antigravity plugin forwards native lifecycle hooks to the Braintrust daemon. The daemon combines exact model and tool boundaries from hooks with the conversation's full JSONL transcript to construct a session, turn, model, and tool span tree.
The hook adapter is synchronous, credential-free, and fail-open. Braintrust
authentication and destination routing remain owned by the bt CLI.
The initial implementation captures PreInvocation, PostInvocation,
PostToolUse, and Stop. It intentionally does not register PreToolUse:
Antigravity requires that hook to return a permission decision. Live testing
confirmed that an empty decision is handled as a denial, while allow would
bypass normal permission checks and ask could add prompts.
This package requires a bt CLI that exposes bt trace hook and a
Unix-compatible sh. Install or refresh the published plugin and configure its
Braintrust route with bt trace enable antigravity (setup remains an alias);
remove its managed registration with bt trace disable antigravity.
The published plugin can also be inspected or installed directly with:
agy plugin install https://github.com/braintrustdata/braintrust-antigravity-pluginThe bt trace enable command remains the recommended entrypoint because it also
persists the Braintrust destination. Managed-run injection, transcript
import/attach, and Windows support are not currently provided.