Core Concepts/Spending Rules

Spending Rules

Every card issued via MPPFinance can carry programmable spending rules that are enforced on-chain. Rules cannot be modified after issuance — they are immutable for the card lifecycle.

Available rules

Rule	Type	Description
merchant	string	Lock card to a single domain (e.g. aws.com)
singleUse	boolean	Card is revoked after the first charge
expiresIn	number	TTL in seconds from issuance time
maxAmount	number	Maximum single-charge amount in cents
dailyCap	number	Maximum total spend per calendar day
network	string	Restrict to solana or ethereum settlement

Full example

rules.ts

const card = await client.issue({
  amount: 200_00,
  currency: 'USD',
  rules: {
    merchant: 'vercel.com',
    singleUse: false,
    expiresIn: 86400,   // 24 hours
    maxAmount: 50_00,   // max $50 per charge
    dailyCap:  200_00,  // max $200 per day
  },
})