langchain-axon

LangChain toolkit for Axon — agentic finance with secure vaults 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

Chain	ID	Status
Base	8453	Live
Arbitrum One	42161	Live
Ethereum	1	Coming soon

Testnet

Chain	ID	Status
Base Sepolia	84532	Live
Arbitrum Sepolia	421614	Live

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

Tool	Description
axon_pay	Send a payment from the vault
axon_balance	Check vault token balance
axon_swap	In-vault token rebalance
axon_execute	DeFi protocol interaction (approve → call → revoke)
axon_poll	Poll async payment/swap/execute status
axon_vault_info	Get vault status, owner, paused state
axon_x402	Handle HTTP 402 Payment Required paywalls

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