Add spend limits for agents

Cap how many paid calls and how much spend a single payer can make.

Pre-release · planned API

import { limit, payers } from "tollstile";

const guarded = toll.price("$0.40", {
  require: [
    limit({ perPayer: "100/hour", spendPerDay: "$20" }),
    payers({ deny: ["0xBAD…"] }),
  ],
});

limit() counts charges from the ledger that were not released, failed, or refunded. Concurrent requests can briefly exceed a limit by the number in flight.
payers() matches payer ids case-insensitively (EVM addresses differ only by checksum casing).
Denials are 429 for limits and 403 for payer rules, and nothing is reserved.

Only for expensive calls

import { amountOver, when } from "tollstile";

toll.price("$10", { require: [when(amountOver("$5"), strongerCheck)] });

Write your own requirement

import type { Requirement } from "tollstile";

const businessHours: Requirement = {
  name: "business-hours",
  async check({ now }) {
    const hour = now.getUTCHours();
    return hour >= 9 && hour < 17 ? { ok: true } : { ok: false, status: 403, reason: "closed" };
  },
};

Requirements also receive claims, a single-use store for nonces, and the quote, which carries a fresh nonce for evidence bound to this request.

Let subscribers through without paying

Give active subscribers free access to paid routes while everyone else pays per call.

Charge for usage

Authorize a maximum per call and settle only what the handler actually used — for LLM, image, and video generation.

On this page

Only for expensive calls Write your own requirement