SSH MCP Server

Instructions

Implementation Reference

• src/index.ts:637-694 (handler)

  The handler for the `ssh_shell_send` MCP tool, responsible for sending input to an active SSH shell session and returning the output.

  private async handleShellSend(args: any): Promise<CallToolResult> {
    this.requireConnection();
    const sessionId = args.sessionId as string;
    const input = args.input as string;
    const raw = (args.raw as boolean) || false;
    const timeout = (args.timeout as number) || SSHMCPServer.SETTLE_TIMEOUT;
    const confirm = args.confirm as boolean | undefined;
  
    const session = this.shellSessions.get(sessionId);
    if (!session) {
      throw new Error(`Sesión "${sessionId}" no encontrada. Usa ssh_shell_start para crear una.`);
    }
  
    // Security check cuando no es raw
    if (!raw) {
      const check = isDangerousCommand(input);
      if (check.dangerous && !confirm) {
        return {
          content: [
            {
              type: "text",
              text: [
                `ADVERTENCIA: Comando potencialmente destructivo detectado.`,
                `Input: ${input}`,
                `Razón: ${check.reason}`,
                ``,
                `Para ejecutar, reenvía con confirm: true.`,
              ].join("\n"),
            },
          ],
        };
      }
    }
  
    // Limpiar buffer antes de enviar
    session.buffer = "";
  
    // Enviar input
    const data = raw ? input : input + "\n";
    session.channel.write(data);
  
    this.resetIdleTimer(sessionId, session);
    this.audit("ssh_shell_send", `sessionId=${sessionId} input=${raw ? "(raw)" : input}`, "ok");
  
    // Esperar output
    return new Promise<CallToolResult>((resolve) => {
      setTimeout(() => {
        resolve({
          content: [
            {
              type: "text",
              text: stripAnsi(session.buffer) || "(sin output)",
            },
          ],
        });
      }, timeout);
    });
  }

• src/tools.ts:210-241 (schema)

  The JSON schema definition for the `ssh_shell_send` tool.

    name: "ssh_shell_send",
    description:
      "Envía input a una sesión de shell activa. Si raw es false (default), aplica detección de comandos peligrosos. Retorna el output generado tras enviar el input",
    inputSchema: {
      type: "object",
      properties: {
        sessionId: {
          type: "string",
          description: "ID de la sesión de shell",
        },
        input: {
          type: "string",
          description: "Texto a enviar a la shell (se agrega \\n automáticamente si raw es false)",
        },
        raw: {
          type: "boolean",
          description:
            "Si es true, envía el input tal cual sin agregar \\n ni aplicar detección de comandos peligrosos (default: false)",
        },
        timeout: {
          type: "number",
          description: "Tiempo en ms para esperar output después de enviar (default: 2000)",
        },
        confirm: {
          type: "boolean",
          description:
            "Confirmar ejecución de comandos peligrosos. Solo aplica cuando raw es false",
        },
      },
      required: ["sessionId", "input"],
    },
  },

• src/index.ts:81-82 (registration)

  Registration of the `ssh_shell_send` tool in the main request handler switch block.

  case "ssh_shell_send":
    return await this.handleShellSend(args);