Axio

A highly extensible, streaming-first agent framework for Python.

Axio gives you a minimal but complete foundation for building LLM-powered agents. Every integration point is a protocol — bring your own transport, context store, tools, and permission guards.

Quick Start

Install the TUI and start chatting with an LLM agent in under a minute.

Quick Start

Getting Started

Write a minimal agent from scratch with the core library.

Getting Started

Core Concepts

Understand the agent loop, protocols, tools, events, and the plugin system.

Core Concepts

How-To Guides

Step-by-step guides for writing custom tools, transports, and guards.

How-To Guides

Packages

Overview of every package in the monorepo and their entry points.

Packages

How to draw an owl

Step 1.

import aiohttp
from axio import Tool, ToolHandler

class Fetch(ToolHandler):
    """Fetch the text content of a URL."""
    url: str

    async def __call__(self) -> str:
        async with aiohttp.ClientSession() as session:
            async with session.get(self.url) as r:
                return (await r.text())[:2000]

fetch = Tool(name="fetch", description=Fetch.__doc__, handler=Fetch)

Step 2.

import asyncio
from axio import Agent, MemoryContextStore
from axio_transport_openai import OpenAITransport

async def main() -> None:
    agent = Agent(
        system="You are a helpful assistant.",
        tools=[fetch],
        transport=OpenAITransport(),
    )
    reply = await agent.run(
        "What's the weather tomorrow? Use geoip for detect my location and wttr.in for weather.",
        MemoryContextStore(),
    )
    print(reply)

asyncio.run(main())

Why Axio?

Extensible by design

Every integration point is a runtime-checkable Protocol or ABC. Swap transports, context stores, tools, and guards without touching framework code.

Streaming by default

All LLM I/O flows through typed StreamEvent values. No hidden buffering — you see every token, tool call, and result as it happens.

Tools are Pydantic models

Define parameters as fields, get JSON schema for free, override __call__ for execution. Guards gate every tool call through a composable permission chain.