Delve MCP

Instructions

Implementation Reference

• src/handlers/debug.ts:41-52 (handler)

  Handler function for the 'exec' tool: parses binary path and args, starts a Delve debug session, and returns session info.

  case "exec": {
    const binary = String(args?.binary);
    const cmdArgs = (args?.args as string[]) || [];
  
    const session = await startDebugSession("exec", binary, cmdArgs);
    return {
      content: [{
        type: "text",
        text: `Started debug session ${session.id} for binary ${binary}`
      }]
    };
  }

• src/server.ts:99-117 (schema)

  Input schema definition for the 'exec' tool, specifying binary path (required) and optional arguments.

  {
    name: "exec",
    description: "Debug a precompiled binary",
    inputSchema: {
      type: "object",
      properties: {
        binary: {
          type: "string",
          description: "Path to the binary"
        },
        args: {
          type: "array",
          items: { type: "string" },
          description: "Arguments to pass to the binary"
        }
      },
      required: ["binary"]
    }
  },

• src/server.ts:406-408 (registration)

  Registers and dispatches the 'exec' tool (among debug tools) to the handleDebugCommands function in CallToolRequest handler.

  if (["debug", "attach", "exec", "test", "core", "dap", "replay", "trace"].includes(name)) {
    return handleDebugCommands(name, args);
  }

• src/session.ts:35-64 (helper)

  Core helper function that implements the execution by spawning 'dlv exec --headless ... binary args' process and manages the debug session.

  export async function startDebugSession(type: string, target: string, args: string[] = []): Promise<DebugSession> {
    const port = await getAvailablePort();
    const id = Math.random().toString(36).substring(7);
    
    const dlvArgs = [
      type,
      "--headless",
      `--listen=:${port}`,
      "--accept-multiclient",
      "--api-version=2",
      target,
      ...args
    ];
  
    const process = spawn("dlv", dlvArgs, {
      stdio: ["pipe", "pipe", "pipe"]
    });
  
    const session: DebugSession = {
      id,
      type,
      target,
      process,
      port,
      breakpoints: new Map()
    };
  
    sessions.set(id, session);
    return session;
  }

• src/types.ts:18-18 (schema)

  Type definition including 'exec' for debug session types.

  type: string; // 'debug' | 'attach' | 'exec' | 'test' | 'core' | 'replay' | 'trace' | 'dap'