small, modular coding-agent harness for Node.js. It demonstrates the core loop behind agentic coding tools without hiding the mechanism behind a framework

Node.js 20+ and an API key for any OpenAI-compatible Chat Completions provider.

npm install
npm start

First run copies agent/config.template.js to config.js. Fill in API_KEY, BASE_URL, and MODEL. Open another directory with npm start -- /my-project.

user task
   ↓
model response
   ↓
tool calls? ── no ──→ final answer
   │
  yes
   ↓
approve + execute local tools
   ↓
append tool results
   ↓
model response again

Tools are read, write, edit, bash, grep, glob, delete, patch, check, fetch, and todo. Specs live in tools/{name}/{name}.json. The LLM client is the OpenAI SDK; point it at any compatible endpoint.

start.js            terminal IDE
agent/agent.js      tool loop
agent/llm.js        OpenAI Chat Completions client
ide/                tree, editor, shell, chat
tools/{name}/       {name}.json + {name}.js

• Agent loop
• Set of tools
• Any OpenAI-compatible provider via BASE_URL in config.js
• Configurable model via MODEL and FALLBACK_MODELS
• File workspace containment checks, including symlink-aware checks
• Interactive approval before writes, edits, and shell commands that leave the git repo
• In a git repo, in-project write/edit/bash calls are auto-approved; outer paths still prompt
• Step limit and tool-output truncation

File tools stay inside the workspace. bash does not: it can reach the network and paths outside the project. In a git repo, in-project writes, edits, and bash auto-approve; otherwise you are prompted. This is not a sandbox. Do not run an untrusted task on a valuable host.

Copyright (c) 2026 How.Programming.Works contributors. Licensed under the MIT License.