MCP GDB Server

Instructions

Implementation Reference

• src/index.ts:560-600 (handler)

  The handleGdbCommand method implements the core logic for the 'gdb_command' tool. It validates the session ID, retrieves the GDB session, executes the provided command using the executeGdbCommand helper, and formats the output response.
  private async handleGdbCommand(args: any) { const { sessionId, command } = args; if (!activeSessions.has(sessionId)) { return { content: [ { type: 'text', text: `No active GDB session with ID: ${sessionId}` } ], isError: true }; } const session = activeSessions.get(sessionId)!; try { const output = await this.executeGdbCommand(session, command); return { content: [ { type: 'text', text: `Command: ${command}\n\nOutput:\n${output}` } ] }; } catch (error) { const errorMessage = error instanceof Error ? error.message : String(error); return { content: [ { type: 'text', text: `Failed to execute command: ${errorMessage}` } ], isError: true }; } }
• src/index.ts:106-119 (schema)

  Input schema for the 'gdb_command' tool defining the required parameters: sessionId (string) and command (string).
  inputSchema: { type: 'object', properties: { sessionId: { type: 'string', description: 'GDB session ID' }, command: { type: 'string', description: 'GDB command to execute' } }, required: ['sessionId', 'command'] }
• src/index.ts:103-120 (registration)

  Registration of the 'gdb_command' tool in the ListToolsRequestSchema handler, providing name, description, and input schema.
  { name: 'gdb_command', description: 'Execute a GDB command', inputSchema: { type: 'object', properties: { sessionId: { type: 'string', description: 'GDB session ID' }, command: { type: 'string', description: 'GDB command to execute' } }, required: ['sessionId', 'command'] } },
• src/index.ts:363-364 (registration)

  Routing registration in the CallToolRequestSchema switch statement that dispatches 'gdb_command' calls to the handleGdbCommand method.
  case 'gdb_command': return await this.handleGdbCommand(request.params.arguments);
• src/index.ts:1159-1217 (helper)

  Core helper function executeGdbCommand that communicates with the GDB process via stdin/stdout, captures output until response markers like '(gdb)', '^done', or '^error', with timeout and error handling.
  private executeGdbCommand(session: GdbSession, command: string): Promise<string> { return new Promise<string>((resolve, reject) => { if (!session.ready) { reject(new Error('GDB session is not ready')); return; } // Write command to GDB's stdin if (session.process.stdin) { session.process.stdin.write(command + '\n'); } else { reject(new Error('GDB stdin is not available')); return; } let output = ''; let responseComplete = false; // Create a one-time event handler for GDB output const onLine = (line: string) => { output += line + '\n'; // Check if this line indicates the end of the GDB response if (line.includes('(gdb)') || line.includes('^done') || line.includes('^error')) { responseComplete = true; // If we've received the complete response, resolve the promise if (responseComplete) { // Remove the listener to avoid memory leaks session.rl.removeListener('line', onLine); resolve(output); } } }; // Add the line handler to the readline interface session.rl.on('line', onLine); // Set a timeout to prevent hanging const timeout = setTimeout(() => { session.rl.removeListener('line', onLine); reject(new Error('GDB command timed out')); }, 10000); // 10 second timeout // Handle GDB errors const errorHandler = (data: Buffer) => { const errorText = data.toString(); output += `[stderr] ${errorText}\n`; }; // Add error handler if (session.process.stderr) { session.process.stderr.once('data', errorHandler); } // Clean up event handlers when the timeout expires timeout.unref(); }); }