Home / Use cases / per-call-charging-llm

Charge per LLM call without a Stripe integration

The problem

Per-call pricing on top of an LLM is the simplest pricing model for an agent tool. Implementing it via Stripe metered billing takes a week and breaks unit economics under $1/call.

What Spawnpay does

One Spawnpay key per end-user. Your tool wraps its expensive call in paywall(). End-user funds the wallet once with $5 of USDC; every call settles in milliseconds against that balance. Withdrawals are free above $1.

Code

import { paywall } from 'spawnpay-paywall';

export const expensiveCall = paywall(
  { price: 0.05, vendor: 'SP_yourCode' },
  async (input) => callMyExpensiveBackend(input)
);
60-SEC QUICKSTART → PLAYGROUND → TOP UP USDC →

What you get with $7 free credit

Every new spk_ wallet starts with $7. That covers 7,000 proxy calls, 1,400 cloud-scrapes, or 700 screenshots — enough to verify Spawnpay fits your workflow before topping up.

See also