2026-09-21-antigravity-headless-became-a-first-class-driver-unlimited-default-timeout-structured-errors-backgroun

Headless became a first-class driver: unlimited default timeout, structured errors, background daemons kept alive. A headless run no longer dies at five minutes, reports machine-readable failure codes, and can leave processes behind on purpose.

Channel: tagged-release. Half: capability. Date: 2026-09-09 to 2026-09-18.

Operator consequence: CI wrappers that relied on the 5-minute cap as a runaway guard must now pass --print-timeout explicitly (>= 1.2.6). Handle exit code 3 and parse AGY_ERROR. Note that a timed-out run exits 0 since 1.1.28; check stderr, not the code. Reap leftover daemon processes on shared runners.

Receipt

• https://github.com/google-antigravity/antigravity-cli/blob/1.2.6/CHANGELOG.md