SSH MCP Server

Instructions

Implementation Reference

• src/index.ts:88-109 (handler)

  Inline handler function that tests the SSH connection by executing the 'hostname' command and returning the result or error details.
  async () => { try { const ssh = await createSshConnection(); try { const { stdout, stderr, exitCode } = await runRemoteCommand(ssh, "hostname"); ssh.end(); const details = JSON.stringify( { exitCode, stderr: stderr.trim(), stdout: stdout.trim() }, null, 2 ); return { content: [{ type: "text", text: details }] }; } finally { // Ensure connection is closed if not already ssh.end(); } } catch (error) { const message = error instanceof Error ? error.message : String(error); return { content: [{ type: "text", text: `SSH connection failed: ${message}` }], isError: true }; } } );
• src/index.ts:83-87 (schema)

  Schema definition for the ssh_test_connection tool, including title, description, and empty input schema.
  { title: "Test SSH Connection", description: "Attempts to connect to the configured SSH host and returns the remote hostname", inputSchema: {}, },
• src/index.ts:81-109 (registration)

  Registration of the ssh_test_connection tool on the MCP server using registerTool, including schema and handler.
  server.registerTool( "ssh_test_connection", { title: "Test SSH Connection", description: "Attempts to connect to the configured SSH host and returns the remote hostname", inputSchema: {}, }, async () => { try { const ssh = await createSshConnection(); try { const { stdout, stderr, exitCode } = await runRemoteCommand(ssh, "hostname"); ssh.end(); const details = JSON.stringify( { exitCode, stderr: stderr.trim(), stdout: stdout.trim() }, null, 2 ); return { content: [{ type: "text", text: details }] }; } finally { // Ensure connection is closed if not already ssh.end(); } } catch (error) { const message = error instanceof Error ? error.message : String(error); return { content: [{ type: "text", text: `SSH connection failed: ${message}` }], isError: true }; } } );
• src/index.ts:32-53 (helper)

  Helper function to create and connect an SSH client using environment variables.
  async function createSshConnection(): Promise<SSHClient> { const env = getEnv(); const ssh = new SSHClient(); const config: ConnectConfig = { host: env.SSH_HOST, port: Number(env.SSH_PORT), username: env.SSH_USERNAME, password: env.SSH_PASSWORD, readyTimeout: 15000, tryKeyboard: false, algorithms: { // Keep defaults; allow host key algo negotiation modern-first }, }; await new Promise<void>((resolve, reject) => { ssh .on("ready", () => resolve()) .on("error", (err: Error) => reject(err)) .connect(config); }); return ssh; }
• src/index.ts:55-73 (helper)

  Helper function to execute a remote command over SSH and capture stdout, stderr, exit code.
  async function runRemoteCommand(ssh: SSHClient, command: string): Promise<{ exitCode: number; stdout: string; stderr: string }>{ return await new Promise((resolve, reject) => { ssh.exec(command, (err: Error | undefined, stream: ClientChannel) => { if (err) return reject(err); let stdout = ""; let stderr = ""; stream .on("close", (code: number) => { resolve({ exitCode: code ?? 0, stdout, stderr }); }) .on("data", (data: Buffer) => { stdout += data.toString(); }) .stderr.on("data", (data: Buffer) => { stderr += data.toString(); }); }); }); }