With the Payments Library, users and AI agents can order Payment Plans by paying for them. The process is simple and secure. The subscriber needs to have enough funds to pay for the plan in the token selected by the creator of the plan. In Nevermined, Payment Plan creators can request payments in any valid ERC-20 or native token (depending on the network where the plan is created). As we discussed in the previous sections, Payment Plans can require payment in fiat (via Stripe integration) or crypto. Because the payment of a fiat payment plan requires the use of a credit card in a web application (via the Nevermined App), crypto payments are recommended for AI agents. That way, the payment and fetching of credits associated with the Payment Plan can be done in a single step.

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Ordering a Plan

// Here we are ordering the plan created in the previous steps
const orderResult = await payments.plans.orderPlan(planId)
// OUTPUT: orderResult:
// {
//   txHash: '0x5b95ebaec594b6d87e688faddf85eec3d708e6a06e61864699e5a366af1343f6',
//   success: true
// }

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Ordering Plans with Fiat Payment

When the Payment Plan requires a payment in fiat, the payment can be initiated with the libraries, but the final step needs to be done in the Nevermined App. The app will handle the payment in fiat (Stripe integration) and will return the user to the application with the Payment Plan ordered. For fiat payments, the process involves redirecting users to a Stripe checkout session: 
// Get fiat payment configuration
const fiatConfig = await payments.plans.getFiatPriceConfig(planId)

// Order plan with fiat payment
const { sessionId, url } = await payments.plans.orderFiatPlan(planId)

// Redirect user to Stripe checkout
window.location.href = url

// After successful payment, user will be redirected back with the plan active

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Checking the Credit Balance of a Payment Plan

After a user purchases a plan, they can check their balance for that plan. The balance represents the number of credits the user has available to use within the plan.
Time-based plans provide a balance of 1 credit for subscribers. When the plan expires, this balance will be zero.
const balanceResult = await payments.plans.getPlanBalance(planId)
// OUTPUT: balanceResult:
// {
//   planId: '84262690312400469275420649384078993542777341811308941725027729655403981619104',
//   planType: 'credits',
//   holderAddress: '0x8924803472bb453b7c27a3C982A08f7515D7aA72',
//   creditsContract: '0x17FaFabF74312EdaBEB1DB9f0CaAccd44aAFDE39',
//   balance: '100',
//   isSubscriber: true
// }

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Understanding Plan Types and Balances

Credits-Based Plans

Users receive a specific number of credits upon purchase. Each API call consumes credits based on your configuration.

Time-Based Plans

Users receive 1 credit that grants unlimited access for the specified duration. Balance becomes 0 when expired.

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Payment Flow Examples

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Complete Purchase Flow

1

Discover Plans

Users browse available payment plans and select one that fits their needs
2

Initiate Purchase

Call payments.plans.orderPlan() or payments.plans.orderFiatPlan() depending on payment method
3

Complete Payment

For crypto: transaction is processed on-chain and happens in one transaction. For fiat: user completes Stripe checkout, and the credits will be distributed automatically after the payment.
4

Verify Purchase

Check balance to confirm the plan was successfully purchased and get the balance. Call payments.plans.getPlanBalance().
5

Access Services

Use the plan to access AI agents and services. Call payments.agents.getAgentAccessToken().

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Error Handling

try {
  const orderResult = await payments.plans.orderPlan(planId)
  
  if (orderResult.success) {
    console.log('Plan purchased successfully!')
    console.log('Transaction hash:', orderResult.txHash)
    
    // Check balance to confirm
    const balance = await payments.plans.getPlanBalance(planId)
    console.log('Available credits:', balance.balance)
  }
} catch (error) {
  console.error('Purchase failed:', error.message)
}

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Best Practices for Plan Purchasing

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Next Steps

After users purchase plans, they can:

Query AI Agents

Learn how to access AI services with purchased plans

Handle Requests

Learn how to process requests and manage responses