nano agent

A minimalistic Python library for building AI agents using functional, immutable DAG operations.

Features

Functional & Immutable - The DAG is immutable. Every operation returns a new instance. No hidden state, no mutations, easy to reason about.

dag = DAG()
dag = dag.system("You are helpful.")  # New DAG
dag = dag.user("Hello")               # New DAG
dag = dag.assistant(response.content) # New DAG

Conversation Graph - Everything is a node in a directed acyclic graph: system prompts, messages, tool calls, results. Branch and merge for parallel tool execution.

Built-in Tools - BashTool, ReadTool, WriteTool, EditTool, GlobTool, SearchTool, PythonTool.

Visualization - Print any DAG to see the conversation flow, or export to HTML:

SYSTEM: You are helpful.
    │
    ▼
USER: What files are here?
    │
    ▼
TOOL_USE: Bash
    │
    ▼
TOOL_RESULT: file1.py, file2.py
    │
    ▼
ASSISTANT: I found 2 Python files...

dag.save("conversation.json")  # Save the graph

uv run nano-agent-viewer conversation.json  # Creates conversation.html

Claude Code Auth - Reuse your Claude Code subscription. No API keys needed.

Quick Start

import asyncio
from nano_agent import ClaudeAPI, DAG, BashTool, run

async def main():
    api = ClaudeAPI()  # Uses ANTHROPIC_API_KEY
    dag = (
        DAG()
        .system("You are a helpful assistant.")
        .tools(BashTool())
        .user("What is the current date?")
    )
    dag = await run(api, dag)
    print(dag)

asyncio.run(main())

Installation

git clone https://github.com/NTT123/nano-agent.git
cd nano-agent
uv sync

nano-tui

Simple terminal UI for debugging:

uv run nano-agent-capture-auth
uv run nano-tui

License

MIT