langchain-axon

LangChain toolkit for Axon — treasury and payment infrastructure for autonomous AI agents.

Gives your LangChain agent 7 tools: pay, check balance, swap tokens, execute DeFi protocols, poll async requests, get vault info, and handle x402 paywalls.

Install

pip install langchain-axon

Prerequisites

Before using this toolkit, you need an Axon vault and a registered bot:

1. Deploy a vault — Go to app.axonfi.xyz, connect your wallet, and deploy a vault. The vault is a non-custodial smart contract that holds your funds. You'll get a vault address (e.g. 0xb8e3...).

2. Fund the vault — Send USDC (or any ERC-20) to your vault address. Anyone can deposit.

3. Register a bot — In the dashboard, go to your vault → Bots → Add Bot. You can generate a new keypair (downloads a keystore file) or bring your own public key. Set spending limits and policies.

4. Get the bot key — Your agent needs the bot's private key to sign payment intents. Either use the keystore file + passphrase, or export the raw private key.

Your wallet (vault owner) stays secure — the bot key can only sign intents within the policies you set. The bot never touches gas or holds funds.

Supported Chains

Mainnet

Testnet

Quick Start

from langchain_axon import AxonToolkit
from langchain_anthropic import ChatAnthropic
from axonfi import Chain

toolkit = AxonToolkit(
    vault_address="0x...",
    chain_id=Chain.BaseSepolia,
    bot_private_key="0x...",
)

llm = ChatAnthropic(model="claude-sonnet-4-20250514")
agent = llm.bind_tools(toolkit.get_tools())

Keystore Authentication

toolkit = AxonToolkit(
    vault_address="0x...",
    chain_id=Chain.Base,
    bot_keystore="bot-keystore.json",
    bot_passphrase="my-secret-passphrase",
)

Environment Variables

AXON_VAULT_ADDRESS=0x...
AXON_CHAIN_ID=84532
AXON_BOT_PRIVATE_KEY=0x...
# or
AXON_BOT_KEYSTORE_PATH=bot-keystore.json
AXON_BOT_PASSPHRASE=my-secret-passphrase

Tools

Individual Tools

from langchain_axon import AxonPay, AxonBalance
from axonfi import AxonClientSync, Chain

client = AxonClientSync(
    vault_address="0x...",
    chain_id=Chain.BaseSepolia,
    bot_private_key="0x...",
)

pay_tool = AxonPay(client=client)
balance_tool = AxonBalance(client=client, chain_id=Chain.BaseSepolia)

Full Agent Example

import os
from langchain_axon import AxonToolkit
from langchain_anthropic import ChatAnthropic
from langchain_core.messages import HumanMessage, SystemMessage, ToolMessage
from axonfi import Chain

toolkit = AxonToolkit(
    vault_address=os.environ["AXON_VAULT_ADDRESS"],
    chain_id=Chain.BaseSepolia,
    bot_private_key=os.environ["AXON_BOT_PRIVATE_KEY"],
)

tools = toolkit.get_tools()
llm = ChatAnthropic(model="claude-sonnet-4-20250514", temperature=0)
llm_with_tools = llm.bind_tools(tools)

messages = [
    SystemMessage(content="You are an AI agent with an Axon payment vault."),
    HumanMessage(content="Check my USDC balance then send 1 USDC to 0xRecipient"),
]

# Agent loop
while True:
    response = llm_with_tools.invoke(messages)
    messages.append(response)

    if not response.tool_calls:
        print(response.content)
        break

    for call in response.tool_calls:
        tool = next(t for t in tools if t.name == call["name"])
        result = tool.invoke(call["args"])
        messages.append(ToolMessage(content=result, tool_call_id=call["id"]))

Links

• Axon Documentation
• Python SDK (axonfi)
• TypeScript SDK (@axonfi/sdk)
• GitHub