Syntax Coding Harness
The Syntax coding harness — TUI sessions with Plan Mode, Runtime Modes, and the full agent experience, started via `syntax-cli`.
The Syntax coding harness is launched with syntax-cli. It's a
distinct binary from the top-level syntax command (which is the
umbrella for the Syntax application itself — connect, deploy, doctor,
models, sessions, memory, and so on). syntax-cli ships bundled with
Syntax; no separate install or syntax connect step is required.
Starting a session
syntax-cliStarts a fresh interactive session in the current working directory. The agent sees the directory's contents (subject to your Runtime Mode and any ignore patterns).
Resuming a session
syntax-cli --resumeLists recent sessions and lets you pick one to resume. Resumed sessions inherit their previous state, including any Plan Mode plan, the working tree at handoff, and Layer-2 memory.
Working with files
The harness has the full set of built-in tools — file editing, shell execution, web search, MCP integrations, the Skills framework, and any specialists deployed in the active party. Tool calls are gated by your active Runtime Mode (see Concepts → Runtime Modes).
Keyboard
A few terminal-specific keybindings:
| Key | Effect |
|---|---|
Ctrl+M | Cycle Runtime Mode (Default → AutoEdit → Bypass → Default). |
Esc | Cancel the current turn — works pre-turn, mid-stream, and over popups. |
Ctrl+C | Soft-quit the session. |
Ctrl+D | Hard-quit. |
Plan Mode in the harness
Plan Mode is a first-class harness experience. Toggle Plan Mode for the current session and the agent enters the plan-then-execute split described in Concepts → Plan Mode. Approved plans persist to disk so you can re-execute them later.
Headless / scripted: syntax-cli exec
For non-interactive use:
syntax-cli exec "fix the failing test in tests/foo.py and add a regression test"exec runs a single task without a TUI and exits. Approvals are
governed by the active policy rather than per-call confirmation;
output is structured for piping into other tools.