tmux_capture_pane

Capture visible text from tmux terminal panes for automation and debugging. Specify session, pane, and lines to extract displayed content or scrollback history.

Instructions

Capture the visible content of a tmux pane. Returns the text currently displayed in the pane.

Input Schema

TableJSON Schema

Name	Required	Description
`session_name`	Yes	Name of the tmux session
`pane_index`	No	Pane index (default: 0 for main pane)
`lines`	No	Number of lines to capture from scrollback (default: captures visible area, use -1 for entire scrollback)

Implementation Reference

src/index.js:333-360 (handler)

The handler function that implements the tmux_capture_pane tool by executing the `tmux capture-pane` command with optional parameters for pane index and number of lines.

async capturePane(args) {
  const { session_name, pane_index = "0", lines } = args;

  try {
    let cmd = `tmux capture-pane -t "${session_name}:${pane_index}" -p`;

    if (lines !== undefined) {
      if (lines === -1) {
        cmd += " -S -"; // Capture entire scrollback
      } else {
        cmd += ` -S -${lines}`;
      }
    }

    const { stdout } = await execAsync(cmd);

    return {
      content: [
        {
          type: "text",
          text: stdout,
        },
      ],
    };
  } catch (error) {
    throw new Error(`Failed to capture pane: ${error.message}`);
  }
}

src/index.js:90-113 (schema)

The input schema and metadata definition for the tmux_capture_pane tool, registered in the list of tools.

{
  name: "tmux_capture_pane",
  description:
    "Capture the visible content of a tmux pane. Returns the text currently displayed in the pane.",
  inputSchema: {
    type: "object",
    properties: {
      session_name: {
        type: "string",
        description: "Name of the tmux session",
      },
      pane_index: {
        type: "string",
        description: "Pane index (default: 0 for main pane)",
      },
      lines: {
        type: "number",
        description:
          "Number of lines to capture from scrollback (default: captures visible area, use -1 for entire scrollback)",
      },
    },
    required: ["session_name"],
  },
},

src/index.js:197-198 (registration)
The switch case that registers and dispatches to the tmux_capture_pane handler in the CallToolRequestSchema handler.
```
case "tmux_capture_pane":
  return await this.capturePane(args);
```

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