Skip to main content
x402 · open payment standard

x402 payments,production-ready.

x402 is the open standard for paying over HTTP 402. Nevermined ships it end to end - your agent gets a signed access token, your endpoint returns a 402, and we verify and settle the charge across crypto and card rails. No relayer, no gas wallet, no bespoke billing.

Read the docsStart building
Audit-ready
ISO 27001SOC 2 Type IIPCI SAQ-D
x402 handshakeone round trip
GET
/v1/search
agent requests a paid endpoint
402
Payment Required
X-PAYMENT · scheme nvm:erc4337
GET
X-PAYMENT: <access-token>
agent retries with the signed token
200
OK · settled ✓
verified, charged, credits burned
The standard

One protocol, two settlement rails

x402 turns the dormant HTTP 402 status code into a real payment handshake. Nevermined implements it with two interchangeable schemes, so the same integration settles in crypto or on a card.

Crypto rail

nvm:erc4337

ERC-4337 smart accounts settle on-chain in USDC. Buyer-signed EIP-712 terms mean the settlement broker can broadcast the leg without ever holding a key.

Card rail

nvm:card-delegation

A delegated Stripe, Braintree, or Visa card pays without a human in the loop. Same 402 handshake, settled to fiat - agents transact on the rails you already run.

Crypto settles each call on-chain; cards buy metered credits you burn down per call. Same 402 handshake - you choose the granularity.

npm i @nevermined-io/paymentsv1.11.2
pip install payments-pyv1.16.1
The flow

Request to settled, four SDK calls.

Two on the buyer, two on the seller. Every call below is real and ships in the Payments SDK today - copy them straight into your agent and your API.

1

Buyer · get token

payments.x402
.getX402AccessToken(
planId, agentId)

The agent mints a signed access token scoped to a plan and a spend limit.

2

Seller · 402

buildPaymentRequired(
planId, {
endpoint, scheme })

Your endpoint answers unpaid calls with a 402 carrying the price and scheme.

3

Seller · verify

payments.facilitator
.verifyPermissions(
{ maxAmount })

Confirm the token can cover the charge before you do the work. No burn yet.

4

Seller · settle

payments.facilitator
.settlePermissions(...)
→ charged · burned ✓

Card charged or crypto moved, credits burned, paid response returned - one call.

Full integration guide ↗
Under the hood

Settlement is the part you don't build

When your endpoint calls verify and settle, Nevermined plays the x402 facilitator role: it checks the token, charges the rail, mints and burns credits, and hands back a receipt. You get three HTTP endpoints and never run a relayer or hold a hot key.

The facilitator endpoints

POST/api/v1/x402/permissions
POST/api/v1/x402/verify
POST/api/v1/x402/settle

Plain HTTP - call them from the SDK or any language directly.

Enterprise-grade by default

The settlement path is audited and card-network compliant, so the trust story is handled before you ship a line of code.

ISO 27001SOC 2 Type IIPCI SAQ-D
Protocol-agnostic

One integration. Both protocols.

Point your agents at any paid endpoint and Nevermined detects the standard it speaks - x402 today, MPP alongside it - then verifies and settles it the same way. Whatever standard wins, your agents can already talk, trade, and trust.

x402Live

Settles across crypto and card rails.

You are here
MPPRolling out

Settles across card and Tempo rails.

Explore MPP →
Runs onERC-4337USDCVisa Intelligent CommerceStripePlatform details →
Get started

Start settling over x402.

Ship agent payments over x402 in an afternoon. Read the docs or talk to the team.
Read the docsTalk to the team