Godot MCP

Instructions

Implementation Reference

• src/index.ts:1754-1847 (handler)

  MCP tool handler for 'export_mesh_library'. Normalizes and validates input parameters (projectPath, scenePath, outputPath, optional meshItemNames), verifies project and scene existence, prepares parameters, executes the Godot 'export_mesh_library' operation via executeOperation method, and handles responses/errors.
  /** * Handle the export_mesh_library tool */ private async handleExportMeshLibrary(args: any) { // Normalize parameters to camelCase args = this.normalizeParameters(args); if (!args.projectPath || !args.scenePath || !args.outputPath) { return this.createErrorResponse( 'Missing required parameters', ['Provide projectPath, scenePath, and outputPath'] ); } if ( !this.validatePath(args.projectPath) || !this.validatePath(args.scenePath) || !this.validatePath(args.outputPath) ) { return this.createErrorResponse( 'Invalid path', ['Provide valid paths without ".." or other potentially unsafe characters'] ); } try { // Check if the project directory exists and contains a project.godot file const projectFile = join(args.projectPath, 'project.godot'); if (!existsSync(projectFile)) { return this.createErrorResponse( `Not a valid Godot project: ${args.projectPath}`, [ 'Ensure the path points to a directory containing a project.godot file', 'Use list_projects to find valid Godot projects', ] ); } // Check if the scene file exists const scenePath = join(args.projectPath, args.scenePath); if (!existsSync(scenePath)) { return this.createErrorResponse( `Scene file does not exist: ${args.scenePath}`, [ 'Ensure the scene path is correct', 'Use create_scene to create a new scene first', ] ); } // Prepare parameters for the operation (already in camelCase) const params: any = { scenePath: args.scenePath, outputPath: args.outputPath, }; // Add optional parameters if (args.meshItemNames && Array.isArray(args.meshItemNames)) { params.meshItemNames = args.meshItemNames; } // Execute the operation const { stdout, stderr } = await this.executeOperation('export_mesh_library', params, args.projectPath); if (stderr && stderr.includes('Failed to')) { return this.createErrorResponse( `Failed to export mesh library: ${stderr}`, [ 'Check if the scene contains valid 3D meshes', 'Ensure the output path is valid', 'Verify the scene file is valid', ] ); } return { content: [ { type: 'text', text: `MeshLibrary exported successfully to: ${args.outputPath}\n\nOutput: ${stdout}`, }, ], }; } catch (error: any) { return this.createErrorResponse( `Failed to export mesh library: ${error?.message || 'Unknown error'}`, [ 'Ensure Godot is installed correctly', 'Check if the GODOT_PATH environment variable is set correctly', 'Verify the project path is accessible', ] ); } }
• src/index.ts:844-872 (schema)

  Input schema and metadata for the 'export_mesh_library' tool, defining required parameters projectPath, scenePath, outputPath and optional meshItemNames array.
  { name: 'export_mesh_library', description: 'Export a scene as a MeshLibrary resource', inputSchema: { type: 'object', properties: { projectPath: { type: 'string', description: 'Path to the Godot project directory', }, scenePath: { type: 'string', description: 'Path to the scene file (.tscn) to export', }, outputPath: { type: 'string', description: 'Path where the mesh library (.res) will be saved', }, meshItemNames: { type: 'array', items: { type: 'string', }, description: 'Optional: Names of specific mesh items to include (defaults to all)', }, }, required: ['projectPath', 'scenePath', 'outputPath'], }, },
• src/index.ts:954-956 (registration)

  Registration of the export_mesh_library handler in the CallToolRequestSchema switch statement.
  case 'export_mesh_library': return await this.handleExportMeshLibrary(request.params.arguments); case 'save_scene':
• src/index.ts:474-542 (helper)

  Helper method executeOperation that runs the Godot headless script (godot_operations.gd) with the specific operation name 'export_mesh_library' and JSON-serialized parameters, capturing stdout/stderr.
  private async executeOperation( operation: string, params: OperationParams, projectPath: string ): Promise<{ stdout: string; stderr: string }> { this.logDebug(`Executing operation: ${operation} in project: ${projectPath}`); this.logDebug(`Original operation params: ${JSON.stringify(params)}`); // Convert camelCase parameters to snake_case for Godot script const snakeCaseParams = this.convertCamelToSnakeCase(params); this.logDebug(`Converted snake_case params: ${JSON.stringify(snakeCaseParams)}`); // Ensure godotPath is set if (!this.godotPath) { await this.detectGodotPath(); if (!this.godotPath) { throw new Error('Could not find a valid Godot executable path'); } } try { // Serialize the snake_case parameters to a valid JSON string const paramsJson = JSON.stringify(snakeCaseParams); // Escape single quotes in the JSON string to prevent command injection const escapedParams = paramsJson.replace(/'/g, "'\\''"); // On Windows, cmd.exe does not strip single quotes, so we use // double quotes and escape them to ensure the JSON is parsed // correctly by Godot. const isWindows = process.platform === 'win32'; const quotedParams = isWindows ? `\"${paramsJson.replace(/\"/g, '\\"')}\"` : `'${escapedParams}'`; // Add debug arguments if debug mode is enabled const debugArgs = GODOT_DEBUG_MODE ? ['--debug-godot'] : []; // Construct the command with the operation and JSON parameters const cmd = [ `"${this.godotPath}"`, '--headless', '--path', `"${projectPath}"`, '--script', `"${this.operationsScriptPath}"`, operation, quotedParams, // Pass the JSON string as a single argument ...debugArgs, ].join(' '); this.logDebug(`Command: ${cmd}`); const { stdout, stderr } = await execAsync(cmd); return { stdout, stderr }; } catch (error: unknown) { // If execAsync throws, it still contains stdout/stderr if (error instanceof Error && 'stdout' in error && 'stderr' in error) { const execError = error as Error & { stdout: string; stderr: string }; return { stdout: execError.stdout, stderr: execError.stderr, }; } throw error; } }
• src/index.ts:136-136 (helper)

  Sets the path to the Godot operations script (godot_operations.gd) which contains the actual implementation logic for the 'export_mesh_library' operation.
  this.operationsScriptPath = join(__dirname, 'scripts', 'godot_operations.gd');