# App Server Test Client Quickstart for running and hitting `codex app-server`. ## Quickstart Run from `/codex-rs`. ```bash # 1) Build debug codex binary cargo build -p codex-cli --bin codex # 2) Start websocket app-server in background cargo run -p codex-app-server-test-client -- \ --codex-bin ./target/debug/codex \ serve --listen ws://127.0.0.1:4222 --kill # 3) Call app-server (defaults to ws://127.0.0.1:4222) cargo run -p codex-app-server-test-client -- model-list ```