Google Antigravity release notes: CLI 1.1.28 changes automated run timeouts

Google Antigravity CLI 1.1.28 changes how automated runs finish. When the time limit expires mid-turn, the tool now returns its partial output and exits successfully, with a warning on stderr. A successful exit therefore does not always mean the task is complete.

The CLI is Antigravity's command-line tool. Headless here means a run without an interactive conversation, using the -p flag. Version 1.1.28 was published on September 9, 2026.

Source: Google Antigravity CLI 1.1.28 on GitHub.

Google Antigravity release notes: timeouts return partial output

Previously, an expired --print-timeout caused a timeout error. The CLI now returns available output and writes a warning to stderr, the program's separate channel for errors and diagnostics. Interrupts such as Ctrl+C still produce a non-zero exit code.

Fatal errors in headless runs get the stable error: marker on stderr. The CLI also prints a note when the response may be truncated and explains runs that previously could end without any output.

Source: Google Antigravity CLI 1.1.28: timeouts and failure reporting.

Background tasks and plan review in headless mode

After the final answer, the CLI waits for running background tasks and scheduled timers, bounded by --print-timeout. Daemon background processes, such as development servers, remain running rather than being terminated.

Non-interactive runs now also proceed through implementation-plan review automatically. This fixes a bug where a run could stall while waiting for approval that nobody could give.

Source: Google Antigravity CLI 1.1.28: shutdown and plan review.

Human step: check how your script interprets the result

If a script starts Antigravity with -p, check after updating that it captures both the answer and stderr. The script should distinguish a complete answer from partial output with a timeout warning, rather than relying only on the exit code. This is our recommendation based on the documented behavior, not a new CLI setting.

Also note a separate change in this version: fetching URLs now asks for approval by default unless access has already been granted.

Source: Google Antigravity CLI 1.1.28: changed defaults.