Tmux MCP Server

Instructions

Implementation Reference

• src/index.ts:137-167 (handler)

  Primary handler and registration for the 'capture-pane' MCP tool. Defines the tool name, description, input schema, and execution logic which parses inputs and delegates to tmux.capturePaneContent helper.

  server.tool(
    "capture-pane",
    "Capture content from a tmux pane with configurable lines count and optional color preservation",
    {
      paneId: z.string().describe("ID of the tmux pane"),
      lines: z.string().optional().describe("Number of lines to capture"),
      colors: z.boolean().optional().describe("Include color/escape sequences for text and background attributes in output")
    },
    async ({ paneId, lines, colors }) => {
      try {
        // Parse lines parameter if provided
        const linesCount = lines ? parseInt(lines, 10) : undefined;
        const includeColors = colors || false;
        const content = await tmux.capturePaneContent(paneId, linesCount, includeColors);
        return {
          content: [{
            type: "text",
            text: content || "No content captured"
          }]
        };
      } catch (error) {
        return {
          content: [{
            type: "text",
            text: `Error capturing pane content: ${error}`
          }],
          isError: true
        };
      }
    }
  );

• src/index.ts:140-144 (schema)

  Zod input schema for capture-pane tool: paneId (string, required), lines (optional string for number of lines), colors (optional boolean for including color sequences).

  {
    paneId: z.string().describe("ID of the tmux pane"),
    lines: z.string().optional().describe("Number of lines to capture"),
    colors: z.boolean().optional().describe("Include color/escape sequences for text and background attributes in output")
  },

• src/tmux.ts:154-157 (helper)

  Core helper function implementing the tmux capture-pane command execution. Supports custom line count (default 200) and optional color inclusion via -e flag.

  export async function capturePaneContent(paneId: string, lines: number = 200, includeColors: boolean = false): Promise<string> {
    const colorFlag = includeColors ? '-e' : '';
    return executeTmux(`capture-pane -p ${colorFlag} -t '${paneId}' -S -${lines} -E -`);
  }