mcp-ssh-tool

Instructions

Implementation Reference

• src/mcp.ts:529-558 (handler)

  The handler logic for the ssh_ping tool which checks if the session exists and executes an 'echo pong' command to verify connectivity.

  case 'ssh_ping': {
    const { sessionId } = SessionIdSchema.parse(args);
    const session = sessionManager.getSession(sessionId);
    if (!session) {
      return {
        content: [{
          type: 'text',
          text: JSON.stringify({ alive: false, error: 'Session not found or expired' }, null, 2)
        }]
      };
    }
  
    try {
      const startTime = Date.now();
      const pingResult = await session.ssh.execCommand('echo pong');
      const latencyMs = Date.now() - startTime;
  
      const result = {
        alive: pingResult.code === 0,
        latencyMs,
        sessionId,
        host: session.info.host,
        remainingMs: Math.max(0, session.info.expiresAt - Date.now())
      };
      logger.info('Session ping', { sessionId, alive: result.alive, latencyMs });
      return { content: [{ type: 'text', text: JSON.stringify(result, null, 2) }] };
    } catch (error) {
      return {
        content: [{
          type: 'text',

• src/types.ts:225-227 (schema)

  Validation schema for the sessionId input parameter used by ssh_ping and other tools.

  export const SessionIdSchema = z.object({
    sessionId: z.string().min(1)
  });

• src/mcp.ts:347-356 (registration)

  Tool registration for ssh_ping within the MCP tool list.

    name: 'ssh_ping',
    description: 'Checks if an SSH session is still alive and responsive',
    inputSchema: {
      type: 'object',
      properties: {
        sessionId: { type: 'string', description: 'SSH session ID to check' }
      },
      required: ['sessionId']
    }
  },