Menu
Give your AI a card.
Not your wallet.
Trust before you pay. Proof after it settles.
It buys two data feeds, prepares an ETH risk brief, and rejects a premium request that breaks your signed limit.
Sign one scoped mandate.
Per-charge, daily, and total caps. One signature.
It routes across supported chains.
Your agent draws from a Universal Account route when the rail is available.
It cannot overpay.
Over-cap charges hit the wall and revert on-chain. Zero gas.
Proof recorded. Revoke anytime.
Every payment ships a verifiable receipt. You hold the kill switch.
Three moments that build trust
Before · After · NextTrust Preview
See who receives the money, on which chain, in what mode, and how proof will be recorded — before you ever confirm.
Proof Receipt
A shareable, verified certificate links the payment transaction and the on-chain proof for the exact invoice.
Permission Firewall
Scoped mandates with per-charge, daily, and total caps + expiry, enforced on-chain by SpendPolicy. Sign once; over-cap charges revert at zero gas. Revoke anytime.
The spending limit x402 is missing
(Coinbase, Cloudflare, AWS) lets an AI agent pay for any API over HTTP — and nothing bounds how much it spends. OneLink Pay is the on-chain leash: one signed mandate, revocable anytime, with a public proof receipt for every payment. We build on the spend-permission wave rather than reinvent it.
OneLink Pay is the on-chain, revocable spending limit for the x402 agent economy — built on Particle + , with a public proof receipt for every payment.
Compare OneLink with existing permission rails
| Prior art | What it is | Where OneLink differs |
|---|---|---|
| Coinbase Agentic Wallets | Vendor MPC agent wallet on Base — bundles an x402 client + programmable spend limits. | No vendor wallet: the limit lives on your own EOA via EIP-7702 (same address), chain-abstracted across EVM chains (Base + Arbitrum), with a public proof receipt. |
| Coinbase Spend Permissions | Allowance (token, period, amount) + revoke for smart wallets. | Wallet-agnostic: the mandate lives on the 7702 Universal Account, plus a public proof receipt. |
| ERC-7715 / 7710 | Emerging standard for wallet-granted scoped permissions + delegation. | A focused, auditable payments mandate aligned to that vocabulary — shipping today. |
| ZeroDev session keys | Low-level account delegation (rate limits, allowed calls). | We enforce a payment policy (per-charge / day / total / merchant) with legible consent. |
| Google AP2 | Agent “mandates” as off-chain Verifiable Credentials. | Same word, but enforced on-chain at your account — a promise becomes a guarantee. |
| x402 (Coinbase) | HTTP 402 pay-per-call rail for agents — no spend controls. | We are the spending-limit layer that bounds x402 spend. |
Built with
Particle
Universal Accounts + EIP-7702 — one balance across supported chains
Magic
Email / Google login — your wallet is your email
Arbitrum
Low-fee USDC settlement where the mandate is enforced
How a payment flows
- 1
Sign in
Email or Google login with Magic — no seed phrase or extension.
- 2
Universal Account
Particle builds a human-readable preview of the transfer.
- 3
USDC settles
Merchant receives USDC on Arbitrum or Base.
- 4
Server verifies
Backend matches the Transfer to the invoice amount.
- 5
Proof recorded
ReceiptEmitter writes an InvoicePaid proof on-chain.
Funds are sourced from supported chains where you hold USDC and settled where the merchant wants — the Universal Account routes it in one operation, with no manual bridge and the network fee paid in USDC. This is the exact Base → Arbitrum flow we proved on-chain.
Funded from Base and delivered on Arbitrum — no manual bridge. The settlement and proof are verified on-chain (above); the funding route is reported by your wallet.
Settled on Arbitrum, verified on-chain. Funding source reported by your wallet: Base, no manual bridge.Integrate in one call
See all three paths →No SDK, no contracts to deploy — every endpoint is a route this app already serves. Create a hosted checkout with one API call; your customer logs in with email or Google and pays in USDC, and the Universal Account sources funds cross-chain and settles on your chain.
Hosted pay link
One API call returns a checkout URL — no SDK, no contracts to deploy.
Server-to-server charge
Charge a payer-signed mandate within its caps; an over-cap charge reverts on-chain, no funds move.
x402 agent leash
Bound an agent's per-call x402 spend to the same on-chain mandate ceiling.
Who adopts it: an x402 API vendor (data, inference, compute) can require a OneLink mandate at agent sign-up — every calling agent then has a hard, revocable per-day ceiling, so the vendor keeps its usage revenue while the agent’s owner holds a spend cap they can prove and pull. The same shape fits a SaaS metering agent usage, or a marketplace handing each automation its own budget.
View live API examples
Create a hosted checkout
curl -s https://onelink-pay.vercel.app/api/payment-links \
-H "content-type: application/json" \
-H "x-admin-create-token: $KEY" \
-d '{"merchantAddress":"0xYourMerchant","amount":"1000000","token":"USDC","destinationChainId":42161}'
# → { "paymentLink": { "id": "…" }, "checkoutUrl": "https://onelink-pay.vercel.app/pay/<id>" }Server-side call — your create token stays secret; the browser only sees the returned checkoutUrl.
Read a walletless firewall verdict
# Walletless — no key, no funds, no gas. Hits the live Arbitrum SpendPolicy.
curl -s https://onelink-pay.vercel.app/api/demo/firewall-block
# → the on-chain verdict, machine-readable:
{
"armed": true,
"blocked": true,
"reason": "over the per-charge cap",
"errorName": "PerChargeExceeded",
"attempted": "0.50",
"cap": "0.10",
"chainId": 42161,
"policy": "0x9782e3724859469fbBAC5085EA8bf8E70724164E"
}The over-cap charge reverts against the live Arbitrum SpendPolicy — nothing moves, no gas. Run it on /try.