Nano: Coding agent in under 200 lines
Nano is a minimal coding agent implemented in under 200 lines of pure Python. It allows users to interact with GPT-5.5 for executing shell commands with human approval. This lightweight tool aims to simplify the process of using coding agents without the need for complex infrastructure.
- ▪Nano is a single-file coding agent that requires no dependencies and can be run directly from GitHub.
- ▪It features a human-in-the-loop approval system for executing commands, ensuring user oversight.
- ▪The architecture is designed to be simple, utilizing a while loop to interact with the language model and execute commands.
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nano.py The models got good enough that the harness doesn't matter anymore. So we made the smallest one that proves it. One file. under 200 lines. Zero dependencies. python3 <(curl -s https://raw.githubusercontent.com/pnegahdar/nano/main/nano.py) That's the whole thing. No, really. Everything below ships in under 200 lines. We counted. 📂 Reads CLAUDE.md, AGENT.md, AGENTS.md, README.md — automatic repo context, same files the real agents use 🧩 Discovers skill files — finds SKILL.md from .claude/skills, ~/.claude/skills, ~/.codex/skills, ~/.codex/plugins 🛡️ Human-in-the-loop approvals — every command shows what and why before it runs 🔁 200-step agentic loop — keeps going until the job is done, not until it gets bored 💬 Interactive REPL — multi-turn sessions with persistent memory…
Excerpt limited to ~120 words for fair-use compliance. The full article is at GitHub.