MCP NodeJS Debugger

Instructions

Implementation Reference

• src/mcp-server.js:819-851 (handler)

  Handler function that implements the list_breakpoints tool logic: ensures debugger enabled, lists breakpoints from inspector.breakpoints as JSON or handles no breakpoints/error cases.

  async () => {
    try {
      // Ensure debugger is enabled
      if (!inspector.debuggerEnabled) {
        await inspector.enableDebugger();
      }
      
      if (inspector.breakpoints.size === 0) {
        return {
          content: [{
            type: "text",
            text: "No active breakpoints"
          }]
        };
      }
      
      const breakpointsList = Array.from(inspector.breakpoints.values());
      
      return {
        content: [{
          type: "text",
          text: JSON.stringify(breakpointsList, null, 2)
        }]
      };
    } catch (err) {
      return {
        content: [{
          type: "text",
          text: `Error listing breakpoints: ${err.message}`
        }]
      };
    }
  }

• src/mcp-server.js:815-852 (registration)

  Registers the 'list_breakpoints' tool with the MCP server using server.tool(), including name, description, empty input schema, and the handler function.

  server.tool(
    "list_breakpoints",
    "Lists all active breakpoints",
    {},
    async () => {
      try {
        // Ensure debugger is enabled
        if (!inspector.debuggerEnabled) {
          await inspector.enableDebugger();
        }
        
        if (inspector.breakpoints.size === 0) {
          return {
            content: [{
              type: "text",
              text: "No active breakpoints"
            }]
          };
        }
        
        const breakpointsList = Array.from(inspector.breakpoints.values());
        
        return {
          content: [{
            type: "text",
            text: JSON.stringify(breakpointsList, null, 2)
          }]
        };
      } catch (err) {
        return {
          content: [{
            type: "text",
            text: `Error listing breakpoints: ${err.message}`
          }]
        };
      }
    }
  );

• src/mcp-server.js:818-818 (schema)

  Empty input schema for the list_breakpoints tool (no parameters required).

  {},