Stablecoin Payments

Accept USDC, EURC, or any ERC-20 token on-chain with the lowest fees and full transparency.

Accept USDC, EURC, or any ERC-20 token directly on-chain. Stablecoin payments are Nevermined’s native payment method, purpose-built for crypto users and autonomous agent-to-agent commerce.

When to Use Stablecoins

Agent-to-Agent Payments

Agents with wallets can purchase plans and pay per request autonomously, with no human in the loop.

Human-to-Agent Purchases

Users buy plans through the Nevermined App checkout page, paying with tokens from their connected wallet.

Crypto-Native Users

Your audience already holds stablecoins and prefers on-chain payments over traditional card flows.

Lowest Fees

Just 1% Nevermined fee with no additional processing surcharges. Ideal for high-volume or high-value use cases.

On-Chain Transparency

Every payment settles on-chain, giving both parties a verifiable, auditable record of every transaction.

How It Works

1. Fund a smart account

   The subscriber funds their Nevermined smart account with ERC-20 tokens (USDC, EURC, or another supported token). This account is an ERC-4337 smart account that supports programmable permissions.

2. Create a delegation

   The subscriber creates a delegation that grants the facilitator permission to execute specific actions (order plans, burn credits, redeem access) on their behalf. Each delegation is scoped by spending limits and duration, following the principle of least privilege.

3. Payment settles on-chain

   When the subscriber purchases a plan or makes a request, the facilitator submits a UserOperation to the smart contract. The payment settles on-chain and credits are minted to the subscriber.

4. Credits consumed per request

   Each API call or agent query burns credits according to the plan configuration. If the subscriber’s balance runs low, the system can auto-order more credits (if the wallet has sufficient balance and the delegation permits it).

Supported Networks and Tokens

Payments settle on the Base network. The most common tokens are:

Token	Description	Base Mainnet	Base Sepolia
USDC	USD-pegged stablecoin by Circle	0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913	0x036CbD53842c5426634e7929541eC2318f3dCF7e
EURC	EUR-pegged stablecoin by Circle	0x60a3E35Cc302bFA44Cb288Bc5a4F316Fdb1adb42	0x808456652fdb597867f38412077A9182bf77359F

Nevermined supports any ERC-20 token on Base. If you need to accept a custom token, you can specify its contract address when creating your plan’s price configuration.

Permission Model

Delegations are the core of the stablecoin permission model. Instead of giving the facilitator full control over a wallet, subscribers create scoped delegations that limit exactly what can be done. The delegation model is shared between crypto (erc4337) and fiat (stripe) payment providers.

Each delegation enforces the principle of least privilege through two limits:

Limit	Description
spendingLimitCents	Maximum total amount (in cents) that can be spent across all transactions
durationSecs	Duration in seconds after which the delegation expires

When the spending limit is exhausted or the delegation expires, it stops working. The subscriber must create a new delegation with fresh limits to continue.

Delegations are created via the SDK before generating an x402 access token:

// Create a delegation for crypto payments
const delegation = await payments.delegation.createDelegation({
  provider: 'erc4337',
  spendingLimitCents: 10000,
  durationSecs: 604800  // 7 days
})

Delegations are revocable at any time by the smart account owner. You always retain full control over your wallet. Under the hood, delegations create the appropriate session keys for the chosen provider.

Fees and Settlement

Item	Cost
Nevermined fee	1% of the plan price
Processing surcharge	None
Settlement	On-chain via Nevermined smart contracts on Base

Because there’s no payment processor in the middle, stablecoin payments carry no additional fees beyond the 1% Nevermined fee. This makes them the most cost-effective option, especially for high-volume use cases.

Supported Plan Types

Credits-Based

Prepaid credits consumed per request. Set total credits and cost per request when creating the plan.

Time-Based

Unlimited access for a set duration (days, months, years). Great for subscription-style access.

Dynamic Pricing

Variable credit charges based on request complexity, token count, or custom metrics.

Hybrid

Combine time-based access with credit limits for balanced monetization.

Trial

Offer free credits or time-limited trials to let users test your agent before purchasing.

Pay-As-You-Go

Per-request settlement in USDC or EURC. No prepaid credits needed — customers pay on demand.

Auto-Order (Pay-As-You-Go)

When a subscriber’s credit balance runs low, the x402 facilitator can automatically purchase more credits on their behalf — no manual balance checks required. This keeps agent-to-agent pipelines running without interruption.

Configure a delegation with spendingLimitCents when generating the access token and the facilitator handles the rest. Total spending is always bounded by that limit, enforced on-chain.

See the Auto-Order guide for enabling this, safety controls, failure handling, and full A2A examples.

Next Steps

Fiat Payments

Accept credit cards via Stripe for mainstream and enterprise users

Payment Models

Configure credits, time-based, dynamic, and hybrid plans

Nevermined x402

Deep dive into the x402 protocol and smart account settlement

Payment Plans API

Create and manage plans programmatically with the TypeScript SDK