code-mode-core

Platform-agnostic engine for code-mode — execute TypeScript code chains with registered tools in a secure V8 sandbox.

This is the core SDK extracted from the n8n-nodes-utcp-codemode community node. Use it to build code-mode integrations for any platform.

Install

npm install code-mode-core

Usage

import { CodeModeEngine } from 'code-mode-core';

const engine = await CodeModeEngine.create();

// Register tool sources (MCP, HTTP, or external tools)
await engine.registerToolSource({
  name: 'fs',
  call_template_type: 'mcp',
  config: {
    mcpServers: {
      filesystem: {
        transport: 'stdio',
        command: 'node',
        args: ['path/to/server-filesystem/dist/index.js', '/allowed/dir']
      }
    }
  }
});

// Execute code with access to all registered tools
const { result, logs } = await engine.execute(`
  const files = fs.filesystem_list_directory({ path: '/tmp' });
  return files;
`, { timeout: 30000, memoryLimit: 128 });

await engine.close();

Features

• Secure V8 sandbox via isolated-vm
• MCP tool integration — register any MCP server as a tool source
• External tool composition — merge platform tools into the sandbox via externalTools API
• Setup caching — FIFO cache (16 entries) keyed by config hash
• Execution tracing — enableTrace returns ToolCallRecord[] with timing data
• TypeScript interfaces — auto-generated from registered tool schemas

Benchmark

96% token savings on a 5-tool pipeline. See the full benchmark.

Related

• n8n-nodes-utcp-codemode — This engine as an n8n community node
• code-mode-tools — This engine as an MCP server
• Code-First n8n Proving Ground — Full lifecycle thesis with POC workflows

License

MPL-2.0