Amp vs Antigravity CLI

Amp

Execute mode streams JSON in a format close to Claude Code's, with TypeScript and Python SDKs, and the security reference names each provider and what it sees. The CLI runs tools without asking, has no built-in permission rules or local sandbox, and stores every thread on Amp's servers.

Antigravity CLI

Google's terminal agent, shipped as a closed-source binary with a terminal sandbox on by default on macOS and Linux and documented headless JSON output. Interactions are used to improve Google products unless users opt out, and a headless run exits 0 when a tool is denied.

Amp

1. Run unattended jobs in a container or VM. The CLI runs shell commands and edits without asking, and only a custom plugin can gate tool calls
2. Set AMP_API_KEY to an access token starting sgamp_ from Settings. The CLI rejects the short-lived token that amp login stores
3. Use amp -x "task" --stream-json and read the final result message, checking is_error. Exit codes are not documented
4. Set AMP_SKIP_UPDATE_CHECK=1 or amp.updates.mode to disabled in CI. Updates install automatically by default
5. Treat the block headed INSTRUCTIONS FOR LLMs in ampcode.com page source as vendor copy, and take facts from the docs Markdown

Antigravity CLI

1. Read the status field from --output-format json and read stderr too. A tool refused for lack of approval still exits 0
2. Pre-approve each shell command and tool a headless run needs with action(target) rules under permissions.allow in ~/.gemini/antigravity-cli/settings.json, because headless runs cannot ask
3. Export GEMINI_API_KEY after setting modelProvider to gemini. The CLI won't start when the key is missing, and setting the variable alone has no effect
4. Turn off Enable Telemetry in the Account settings before running on private repositories if Interactions should not be used for product improvement
5. Set --print-timeout explicitly. The docs give a five-minute default, while agy --help shows 0s