usevig402

HTTP 402 · x402 · Base

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 human — and no ETH for gas.

Run it live → Read /llms.txt OpenAPI
Agent signs offline Merchant your wallet USDC — direct usevig relays signature
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.

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

EndpointWhat it does
POST /v1/merchantsCreate a merchant. Base Sepolia is self-serve.
POST /v1/paymentsCreate a charge; returns the 402 challenge.
POST /v1/payments/:id/settleVerify a signature and relay on-chain.
GET /v1/payments/:idStatus, tx hash, confirmations.
GET /v1/meTier and usage this period.
POST /mcpMCP server for agent self-onboarding.