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
Fund a smart account
The subscriber funds their Nevermined smart account with ERC-20 tokens (USDC, USDT, or another supported token). This account is an ERC-4337 smart account that supports programmable permissions.
Create session keys
The subscriber generates scoped session keys that grant the facilitator permission to execute specific actions (order plans, burn credits, redeem access) on their behalf. Each key follows the principle of least privilege.
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.
Supported Networks and Tokens
Payments settle on the Base network. The most common tokens are:| Token | Description |
|---|---|
| USDC | USD-pegged stablecoin by Circle |
| USDT | USD-pegged stablecoin by Tether |
Permission Model
Session keys are the core of the stablecoin permission model. Instead of giving the facilitator full control over a wallet, subscribers create scoped keys that limit exactly what can be done. Each session key enforces the principle of least privilege through three limits:| Limit | Description |
|---|---|
orderLimit | Maximum token amount the key can spend on plan purchases |
redemptionLimit | Maximum number of credit burn or redeem operations the key can perform |
expiresAt | Expiration date after which the key becomes invalid |
Session keys are revocable at any time by the smart account owner. You always retain full control over your wallet.
Fees and Settlement
| Item | Cost |
|---|---|
| Nevermined fee | 1% of the plan price |
| Processing surcharge | None |
| Settlement | On-chain via Nevermined smart contracts on Base |
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. No prepaid credits needed — customers pay on demand.
Auto-Ordering
When a subscriber’s credit balance runs low, the system can automatically purchase more credits on their behalf. This happens seamlessly if:- The subscriber’s wallet has sufficient token balance
- The active session key has remaining
orderLimitcapacity - The plan supports re-ordering
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