EDA Tools MCP Server

Instructions

Implementation Reference

• src/index.ts:267-330 (handler)

  Core handler implementation for the 'view_waveform' tool. Validates the project ID, locates the VCD file, checks for GTKWave availability, and launches GTKWave to display the waveform.

  async viewWaveform(projectId: string, vcdFile = "output.vcd"): Promise<string> {
    try {
      // Check if project exists
      const project = this.projects.get(projectId);
      if (!project) {
        return JSON.stringify({
          success: false,
          error: `Project ${projectId} not found. Run a simulation first.`,
        }, null, 2);
      }
  
      const vcdPath = join(project.dir, vcdFile);
  
      // Check if VCD file exists
      try {
        await fs.access(vcdPath);
      } catch {
        // List available files to help user
        const files = await fs.readdir(project.dir);
        const vcdFiles = files.filter(f => f.endsWith('.vcd'));
        
        return JSON.stringify({
          success: false,
          error: `VCD file '${vcdFile}' not found in project ${projectId}`,
          available_vcd_files: vcdFiles,
          note: "Make sure your testbench includes $dumpfile() and $dumpvars() commands"
        }, null, 2);
      }
  
      // Check if GTKWave is available
      if (!(await commandExists('gtkwave'))) {
        return JSON.stringify({
          success: false,
          error: "GTKWave not found. Please install GTKWave to view waveforms.",
          install_instructions: {
            macos: "brew install gtkwave",
            linux: "sudo apt-get install gtkwave",
            windows: "Install GTKWave from http://gtkwave.sourceforge.net/"
          }
        }, null, 2);
      }
  
      // Launch GTKWave in background
      const gtkwaveCmd = `gtkwave "${vcdPath}" &`;
      await execAsync(gtkwaveCmd, { 
        cwd: project.dir, 
        timeout: 5000 
      });
  
      return JSON.stringify({
        success: true,
        message: `GTKWave launched for project ${projectId}`,
        vcd_file: vcdFile,
        vcd_path: vcdPath,
        project_type: project.type
      }, null, 2);
  
    } catch (error: any) {
      return JSON.stringify({
        success: false,
        error: error.message || String(error),
      }, null, 2);
    }
  }

• src/index.ts:768-785 (registration)

  Registration of the 'view_waveform' tool in the MCP server's tool list, including description and input schema definition.

    name: "view_waveform",
    description: "Open VCD waveform file in GTKWave viewer",
    inputSchema: {
      type: "object",
      properties: {
        project_id: { 
          type: "string", 
          description: "Project ID from simulation (required)" 
        },
        vcd_file: { 
          type: "string", 
          description: "VCD filename (default: output.vcd)",
          default: "output.vcd"
        },
      },
      required: ["project_id"],
    },
  },

• src/index.ts:891-901 (handler)

  Tool dispatch handler in the CallToolRequestSchema that extracts parameters and invokes the EDAServer.viewWaveform method.

  case "view_waveform": {
    const projectId = validateRequiredString(args, "project_id", name);
    const vcdFile = getStringProperty(args, "vcd_file", "output.vcd");
    
    return {
      content: [{
        type: "text",
        text: await edaServer.viewWaveform(projectId, vcdFile),
      }],
    };
  }