axonfi 0.2.3

Python SDK for Axon — treasury and payment infrastructure for autonomous AI agents

axonfi

Python SDK for Axon — treasury and payment infrastructure for autonomous AI agents.

Axon lets bot operators deploy non-custodial vaults, register bot public keys, define spending policies, and let their bots make gasless payments — without bots ever touching private keys or gas.

Installation

pip install axonfi

Prerequisites

Before using the SDK, you need an Axon vault with a registered bot:

1. Deploy a vault — Go to app.axonfi.xyz, connect your wallet, and deploy a vault on your target chain. The vault is a non-custodial smart contract — only you (the owner) can withdraw funds.

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

3. Register a bot — In the dashboard, go to your vault → Bots → Add Bot. You can either:

   • Generate a new keypair (recommended) — the dashboard creates a key and downloads an encrypted keystore JSON file. You set the passphrase.
   • Bring your own key — paste an existing public key if you manage keys externally.

4. Configure policies — Set per-transaction caps, daily spending limits, velocity windows, and destination whitelists. The bot can only operate within these bounds.

5. Get the bot key — Your agent needs the bot's private key to sign payment intents. Use the keystore file + passphrase (recommended) or export the raw private key for quick testing.

The vault owner's wallet stays secure — the bot key can only sign intents within the policies you configure, and can be revoked instantly from the dashboard.

Quick Start

Option 1: Keystore file + passphrase (recommended)

When you register a bot on the Axon dashboard, it generates a keystore JSON file. This is the safest way to load a bot key — the private key stays encrypted on disk and only lives in memory while the bot runs.

import json
from eth_account import Account
from axonfi import AxonClient, Chain, Token

# Load encrypted keystore file (downloaded from the dashboard)
with open("bot-keystore.json") as f:
    keystore = json.load(f)

# Decrypt with your passphrase (set when you registered the bot)
private_key = Account.decrypt(keystore, "your-passphrase")

client = AxonClient(
    vault_address="0x...",
    chain_id=Chain.BaseSepolia,
    bot_private_key="0x" + private_key.hex(),
)

# Pay 5 USDC — SDK handles decimals automatically
result = await client.pay(
    to="0x...recipient...",
    token=Token.USDC,
    amount=5,
    memo="API call #1234 — weather data",
)

print(result.status, result.tx_hash)

Option 2: Raw private key (for quick testing)

from axonfi import AxonClient, Chain

client = AxonClient(
    vault_address="0x...",
    chain_id=Chain.BaseSepolia,
    bot_private_key="0x...",  # From env var or .env file — never hardcode
)

result = await client.pay(to="0x...", token=Token.USDC, amount=5)

Synchronous Usage (LangChain, CrewAI)

Both options work with the sync client too — just swap AxonClient for AxonClientSync:

from axonfi import AxonClientSync, Chain, Token

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

result = client.pay(to="0x...", token=Token.USDC, amount=5)

Features

• EIP-712 signing for all intent types (payment, execute, swap)
• Async + sync clients — use AxonClient (async) or AxonClientSync
• Human-friendly amounts — pass 5 or "5.2" instead of 5000000
• Token registry — use "USDC" or Token.USDC instead of addresses
• Full relayer API — pay, execute DeFi protocols, swap, poll, check balances

API Reference

AxonClient / AxonClientSync

Method	Description
pay(to, token, amount, ...)	Create, sign, and submit a payment
execute(protocol, call_data, token, amount, ...)	DeFi protocol interaction
swap(to_token, min_to_amount, ...)	In-vault token swap
get_balance(token)	Vault balance for a token
get_balances(tokens)	Multiple balances in one call
is_active()	Whether this bot is active
is_paused()	Whether the vault is paused
get_vault_info()	Owner, operator, paused, version
can_pay_to(destination)	Destination whitelist/blacklist check
poll(request_id)	Poll async payment status

Signing Utilities

from axonfi import sign_payment, encode_ref, PaymentIntent

ref = encode_ref("my memo")
intent = PaymentIntent(bot="0x...", to="0x...", token="0x...", amount=1000000, deadline=1700000000, ref=ref)
signature = sign_payment(private_key, vault_address, chain_id, intent)

Constants

from axonfi import Chain, USDC, Token, KNOWN_TOKENS

chain_id = Chain.BaseSepolia       # 84532
usdc_addr = USDC[chain_id]        # 0x036CbD...
decimals = KNOWN_TOKENS["USDC"].decimals  # 6

HTTP 402 Paywalls (x402)

The SDK includes utilities for handling x402 paywalls — APIs that charge per-request via HTTP 402 Payment Required.

import httpx
from axonfi import (
    parse_payment_required,
    find_matching_option,
    extract_x402_metadata,
    format_payment_signature,
)

response = await httpx.AsyncClient().get("https://api.example.com/data")

if response.status_code == 402:
    # 1. Parse the PAYMENT-REQUIRED header
    header = response.headers["payment-required"]
    parsed = parse_payment_required(header)

    # 2. Find a payment option matching your chain
    option = find_matching_option(parsed.accepts, client.chain_id)

    # 3. Fund the bot from the vault
    result = await client.pay(
        to=client.bot_address,
        token=option.asset,
        amount=int(option.amount),
        x402_funding=True,
    )

    # 4. Sign the authorization and retry
    signature_header = format_payment_signature({
        "scheme": "exact",
        "signature": "...",  # EIP-3009 or Permit2 sig
    })

    data = await httpx.AsyncClient().get(
        "https://api.example.com/data",
        headers={"PAYMENT-SIGNATURE": signature_header},
    )

The full pipeline applies — spending limits, AI verification, human review — even for 402 payments. Vault owners see every paywall payment in the dashboard with the resource URL, merchant address, and amount.

Supports EIP-3009 (USDC, gasless) and Permit2 (any ERC-20) settlement schemes.

Supported Chains

Mainnet

Chain	ID	Status
Base	8453	Coming soon
Arbitrum One	42161	Coming soon

Testnet

Chain	ID	Status
Base Sepolia	84532	Live
Arbitrum Sepolia	421614	Live

Links

• Website
• Dashboard
• Documentation
• PyPI — axonfi
• npm — @axonfi/sdk (TypeScript SDK)
• Smart Contracts
• Examples
• GitHub
• Twitter/X — @axonfixyz