v0.2.0 — Antigravity support

Cempala now works with Antigravity (Google's agy CLI) alongside Claude Code and Codex — in both directions. dispatch can target it, and Antigravity can call Cempala's eight tools itself.

Antigravity

• target_agent: "antigravity" runs agy -p headless and returns the result inline, like the other two.
• Registration is automatic. Antigravity has no mcp add, so the installer merges an entry into ~/.gemini/config/mcp_config.json — covering both the Antigravity IDE and the CLI. Every other server and top-level key in that file is preserved, and a config that can't be parsed is left untouched with the snippet printed for you. Re-runnable on its own with cempala --register-antigravity.

Two things about this agent are worth knowing before you rely on it:

• allow_network: false cannot be enforced for Antigravity. agy has no argv-level network switch — its reach is governed by read_url / execute_url in your own agy settings, which Cempala neither reads nor writes. Rather than borrow a label it can't back up, the result reports a fourth value, network_enforcement: "not_enforceable". Codex still reports "sandboxed" and Claude "tools_only".
• Shell commands are auto-denied in headless mode unless you add an allow-rule under permissions.allow in ~/.gemini/antigravity-cli/settings.json. File edits work out of the box. Cempala will not pass --dangerously-skip-permissions to get around this.

Fixes that affect Claude and Codex too

• A run that produced nothing is no longer reported as a success. Every path that settled a task read stderr only when the run had already failed, so a run that exits 0 with an empty answer came back completed with an empty result — and the one line explaining why was discarded. An empty answer now earns the stderr read, and an agent explicitly stating it produced no output is recorded as failed.
• Dispatched work lands in the cwd you asked for. agy resolves relative paths against its own workspace, not the process cwd, so a dispatch could write into ~/.gemini/antigravity-cli/scratch instead of your project. The baseline now anchors it with --add-dir <validated cwd>.
• The reaper reports what actually happened instead of falling through to a canned message when stdout was empty.
• The installer can't be hung by an older binary. A cempala predating --register-antigravity doesn't reject the flag — it starts the stdio server and reads stdin. Both installers now close the child's input.

Upgrading

Re-run the installer; it's idempotent and replaces the binary in place even while it's running.

curl -fsSL https://raw.githubusercontent.com/thelabs-id/cempala/main/scripts/install.sh | bash

Restart any Claude Code, Codex or Antigravity session that's already open so it picks up the registration.

Verifying these binaries

Every asset is listed in checksums.txt, and the installers refuse to install without a matching line. These are the exact bytes CI smoke-tested on matching hardware for each platform. cempala-windows-arm64.exe is deliberately not published — it has no smoke-test runner yet, and Windows on ARM runs the x64 build under emulation, which the installer selects for you.