Payments your agent can pay by itself.

Your agent hits a paywalled endpoint, gets back a signable challenge, signs it with its own wallet, and the payment settles on-chain in seconds. No card, no checkout, no ETH for gas. And when a person needs to pay instead, send them a link.

Run it live → See the checkout page Read /llms.txt

Non-custodial by construction — usevig sits beside the transfer, never inside it.

Run it live

Real calls against Base Sepolia. No signup, no email, no funds.

create merchant create charge 402 challenge

# Press “Run request”. These are real API calls — nothing here is mocked.

For people, too

Every charge comes with a page a human can pay on.

The same API call that returns a 402 challenge for your agent also returns a checkout_url. Send it to a customer and they connect a browser wallet, see exactly what they're authorizing, and sign. Same charge, same verification, same settlement — usevig just has two front doors instead of one.

No account, no API key, nothing held in escrow. They sign a transfer straight to your wallet.

Open a live testnet checkout →

Why it holds up

Your keys, your money

Settlement is EIP-3009 transferWithAuthorization: value moves straight from payer to merchant. There is no usevig address in the path, not for one block.

We pay the gas

usevig submits the transaction as a relayer, so neither your agent nor the merchant needs ETH. About $0.00103 per mainnet payment, all-in — L2 execution plus the L1 data fee.

Priced per transaction

Metered on transactions verified, never on value transferred. Move $1M or $10k — same bill at the same count.

Replay-proof

Every nonce is single-use, rejected by both a database uniqueness constraint and an on-chain authorizationState check.

Finality, not optimism

Nothing is called final at one confirmation. Configurable depth per merchant, with reorg demotion if a transaction disappears.

Built for agents

An MCP server, /llms.txt, and a free Base Sepolia tier needing zero credentials. An agent can onboard and transact without a human touching anything.

Pricing

FreeBase Sepolia · 10,000 relays / mo

$49up to 11,000 mainnet tx / mo

$299up to 72,000 mainnet tx / mo

Customself-hosted relayer

The test tier is Base Sepolia: free, self-serve, and the identical code path — real signatures, a real relay, real confirmations, worthless gas. Mainnet is paid only, because every mainnet relay costs us real gas. We charge for verification work, not for moving money. Paid plans carry a per-period relay-gas budget of half the plan price. Today your full included volume fits well inside it; if gas costs spike the budget is what stops relays, which is why the figures say “up to”. GET /v1/me shows both counters and which one is binding. That is deliberate: usevig is a relayer and never takes custody of funds, which is what keeps it out of money-transmitter territory. Refunds and disputes stay between the merchant and their customer — an on-chain transfer cannot be reversed by us.

API

Endpoint	What it does
`POST /v1/merchants`	Create a merchant. Base Sepolia is self-serve.
`POST /v1/payments`	Create a charge; returns the 402 challenge.
`POST /v1/payments/:id/settle`	Verify a signature and relay on-chain.
`GET /v1/payments/:id`	Status, tx hash, confirmations.
`GET /pay/:id`	Hosted checkout page for a human. Public, no key.
`GET /v1/me`	Tier and usage this period.
`POST /mcp`	MCP server for agent self-onboarding.