run_python

Instructions

Implementation Reference

• src/services/CodeExecutionService.ts:162-186 (handler)

  The main handler function that executes Python code or scripts. Accepts code (inline string), script_path (file path), args (command-line arguments), and venv (virtual environment). Builds the command string using python3/python/py and delegates to executeWithStreaming.

  async runPython(args: PythonExecutionArgs): Promise<ToolResult> {
    const { code, script_path, args: scriptArgs = [], venv } = args;
    
    if (!code && !script_path) {
      throw new Error('Either code or script_path must be provided');
    }
    
    let command: string = '';
    
    if (code) {
      // Check for Python availability
      const pythonCmd = venv ? `${venv}/bin/python3` : await this.getPythonCommand();
      const escapedCode = code.replace(/"/g, '\\"').replace(/\$/g, '\\$');
      command = `${pythonCmd} -c "${escapedCode}"`;
      if (scriptArgs.length > 0) {
        command += ` ${scriptArgs.join(' ')}`;
      }
    } else if (script_path) {
      const pythonCmd = venv ? `${venv}/bin/python3` : await this.getPythonCommand();
      const fullPath = this.workspaceService.resolvePath(script_path);
      command = `${pythonCmd} ${this.quotePath(fullPath)} ${scriptArgs.join(' ')}`;
    }
    
    return this.executeWithStreaming(command, { cwd: this.getCurrentWorkspace() });
  }

• src/services/CodeExecutionService.ts:10-15 (schema)

  TypeScript interface for PythonExecutionArgs input schema with optional fields: code, script_path, args (string array), and venv.

  export interface PythonExecutionArgs {
    code?: string;
    script_path?: string;
    args?: string[];
    venv?: string;
  }

• src/toolDefinitions.ts:143-156 (schema)

  Tool registration schema with name 'run_python', description, and inputSchema (object with code, script_path, args, venv properties) used for MCP tool listing.

  // Code Execution
  {
    name: 'run_python',
    description: 'Execute Python code or script',
    inputSchema: {
      type: 'object',
      properties: {
        code: { type: 'string', description: 'Python code to execute' },
        script_path: { type: 'string', description: 'Path to Python script file' },
        args: { type: 'array', items: { type: 'string' }, description: 'Command line arguments' },
        venv: { type: 'string', description: 'Path to virtual environment' },
      },
    },
  },

• src/index.ts:170-172 (registration)

  Case statement in executeToolCommand switch that routes 'run_python' tool calls to CodeExecutionService.runPython(args).

  // Code Execution
  case 'run_python':
    return await this.codeExecutionService.runPython(args);

• src/services/CodeExecutionService.ts:320-331 (helper)

  Helper that auto-detects which Python command (python3, python, or py) is available on the system by running --version.

  private async getPythonCommand(): Promise<string> {
    const commands = ['python3', 'python', 'py'];
    for (const cmd of commands) {
      try {
        await this.executeWithStreaming(`${cmd} --version`, {}, 5000);
        return cmd;
      } catch {
        // Try next command
      }
    }
    throw new Error('Python not found. Please install Python 3.x');
  }