Give your agents a payment stack they can trust.
Discover paid APIs, enforce durable spending policy, settle USDC on-chain, and gate work on independent validation—all from one Python SDK.
pip install arc-agent-payOne agent run, end to end
- 402 Payment Required
POST /research
no API key sent
- signed
sign transfer · 0.005 USDC
EIP-3009, off-chain
- 200 OK
retry with X-PAYMENT
settles on Arc Testnet
Arc Testnet · x402 Protocol · EIP-3009 · Circle USDC
One client, explicit policy
Add autonomous payments without hiding the controls.
PaymentClient handles the 402 flow while your policy and SQLite journal keep every authorization bounded, durable, and inspectable.
from arc_agent_pay import PaymentClient, PaymentPolicy, SqlitePaymentStore
policy = PaymentPolicy(
max_payment_usdc="0.05",
daily_cap_usdc="2.00",
)
async with PaymentClient(
account=account,
policy=policy,
payment_store=SqlitePaymentStore("payments.db"),
) as client:
response = await client.get(url)Settlement
Automatic x402 negotiation and EIP-3009 USDC settlement with explorer-verifiable receipts.
Identity
ERC-8004 agent identity, reputation checks, and evidence-bound validation attestations.
Workflow
Durable policy and payment journals, validation escrow, and an ERC-8183 client profile.
We take care of the plumbing.
Budgets that actually hold.
Every run gets a hard cap. Quote-aware policy adds maximum-price, rolling spend, velocity, provider, network, asset, recipient, and kill-switch controls before any signature.
Agents find the right API on their own.
A built-in registry ranks services by name, tags, and description. Your agent searches for what it needs — 'crypto prices' — and gets back live, payable endpoints.
Your agent code never changes.
PaymentClient is a drop-in HTTP client. When a server answers 402, the payment is signed, attached, and retried behind the scenes — your application logic stays exactly as it was.
- amount
- 0.005 USDC
- network
- Arc Testnet
- tx
- 0x9f2c…a41b
Every payment on the record.
A durable SQLite journal records quoted terms and pending, authorized, settled, failed, or ambiguous outcomes. Successful settlement still links to its Arc explorer transaction.
An agent pays. The protocol settles.
Five steps, a few seconds, every payment verifiable on-chain.
Request
The agent calls a paid API — no auth header, no API key.
402
The server answers with a price: 0.005 USDC, payable on Arc.
Sign
The agent signs an EIP-3009 authorization off-chain. No gas.
Retry
The signed payment rides along in the X-PAYMENT header.
Settle
The server settles on Arc Testnet and returns 200 with the tx hash.
Hosted playground activity.
Live runs and on-chain payments made by this public playground.
Frequently asked
An open-source Python SDK that lets AI agents pay for APIs as they use them. Servers price each call over the x402 protocol, and the agent settles in USDC on Arc Testnet — no accounts, no API keys.
Give your agents a wallet of their own.
Run a live agent in the browser — no signup, no keys, no gas. Watch it discover an API, pay in USDC, and settle on Arc Testnet in seconds.