Run command¶

Use when you need to run a shell command in a pane and get a RunCommandResult with exit status, timeout state, and captured pane output.

Avoid when you need raw interactive key driving — use send_keys or send_keys_batch for TUIs, key names, and partial commands.

Side effects: Sends a command to the pane’s interactive shell. The command may read or write files, start processes, or access the network depending on what the shell command does. Each command runs in a subshell, so directory or environment changes do not persist across calls.

For MCP calls, lightweight suppression is enabled by default. The configuration setting LIBTMUX_SUPPRESS_HISTORY controls only omitted MCP suppress_history arguments, and an explicit suppress_history value wins. Direct Python calls default to False. suppress_history=false permits intentional multiline input.

Suppression is best effort: run_command prefixes one space to the grouped event that carries your single-line command, but the existing shell must be configured to ignore space-prefixed commands. When suppression is effective, a command containing a carriage return or line feed is rejected before tmux receives input because one prefix cannot protect multiple shell events. This control does not change the shell’s environment or startup configuration, clear its memory or pane scrollback, or hide the command from other observers. See History suppression for shell behavior and Safety tiers before handling credentials.

Example:

{
  "tool": "run_command",
  "arguments": {
    "command": "pytest -q",
    "pane_id": "%2",
    "timeout": 60
  }
}

Response (RunCommandResult):

{
  "pane_id": "%2",
  "exit_status": 0,
  "timed_out": false,
  "elapsed_seconds": 4.2,
  "output": ["..."],
  "output_truncated": false,
  "output_truncated_lines": 0
}

Parameters