profullstack · ralyodio · Sep 5, 2026 · Sep 5, 2026
diff --git a/README.md b/README.md
@@ -4,6 +4,8 @@ Sell crawl access to AI training crawlers, by the day, over [x402](https://x402.
 
 People read your site free. So do search engines and the retrieval crawlers behind AI answers, because they send readers back. A crawler that copies pages into a training corpus sends nobody back, so it pays: every page answers `402 Payment Required` with an x402 offer, paying the offer returns a signed pass, and the pass opens the site for a day.
 
+A crawler that wants longer buys more days in one payment. `?days=7` on the sales page quotes seven days at the daily price, and the days a proof buys are read off the value it authorizes, so paying seven times the price — however it was asked for — returns a pass that expires seven days out. `maxDays` caps how many one proof can buy.
+
 One middleware. No database. Runs in Node, Bun and at the edge.
 
 ```
@@ -82,7 +84,8 @@ export const GET = robotsRoute(gateway, { disallow: ['/login', '/api/'] });
 | `coinpay.apiKey` | | a **scoped** CoinPay key (`cp_live_…`, from the business's API Keys tab) with `payments:create`. The legacy business key is refused by CoinPay's x402 routes. |
 | `payTo` | | EVM address that receives the USDC, on Base, Polygon and Ethereum alike |
 | `priceCents` | `100` | |
-| `passMinutes` | `1440` | a day |
+| `passMinutes` | `1440` | a day: the term one price buys |
+| `maxDays` | `30` | the most terms one proof may buy at once |
 | `header` | `x-crawl-pass` | where the pass goes; `Authorization: Bearer` works too |
 | `path` | `/crawl` | the sales page |
 | `openPaths` | `[]` | extra paths a refused crawler may read (`robots.txt`, the sales page, `security.txt` and `.well-known/` always are) |

diff --git a/index.d.ts b/index.d.ts
@@ -7,16 +7,27 @@ export interface Sale {
   token: string;
   expiresAt: string;
   userAgent: string;
+  /** Per term (`passMinutes`). */
   priceCents: number;
+  /** Terms this proof bought. */
+  days: number;
+  /** `priceCents * days`. */
+  totalCents: number;
   currency: string;
 }
 
 export interface PageContext {
   siteName: string;
   siteUrl: string;
   buyUrl: string;
+  /** Per day, e.g. "1.00 USD". */
   price: string;
   minutes: number;
+  /** Days this page's offer quotes (`?days=`), 1 by default. */
+  days: number;
+  /** `price` times `days`. */
+  total: string;
+  maxDays: number;
   header: string;
   enabled: boolean;
   offer: Offer;
@@ -37,8 +48,10 @@ export interface GatewayOptions {
   /** Default 100 ($1). */
   priceCents?: number;
   currency?: string;
-  /** What a payment buys. Default 1440 (a day). */
+  /** What one price buys. Default 1440 (a day). */
   passMinutes?: number;
+  /** The most terms one proof may buy at once (`?days=` and paid multiples are clamped to it). Default 30. */
+  maxDays?: number;
   /** Request header the pass is presented in. Default 'x-crawl-pass'. */
   header?: string;
   /** The sales page. Default '/crawl'. */
@@ -133,6 +146,10 @@ export const X402_METHODS: typeof METHODS;
 export function buildOffer(args: { payTo: string; priceCents: number; resource: string; description?: string; maxTimeoutSeconds?: number; methods?: typeof METHODS }): Offer;
 export function decodePayment(header: string | null | undefined): Record<string, unknown> | null;
 export function expectedFor(payment: unknown, offer: Offer): { amount: string; resource: string; payTo: string; asset: string } | null;
+/** The value a proof authorizes, in the token's smallest unit, or null. */
+export function paidValueOf(payment: unknown): bigint | null;
+/** How many terms `value` buys at `unit` per term: a whole number in [1, maxDays], or 0. */
+export function daysPaid(value: bigint | null, unit: string | number | bigint, maxDays: number): number;
 export function verifyAndSettle(
   payment: unknown,
   expected: { amount: string; resource: string; payTo: string; asset: string },

diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@profullstack/x402-gateway",
-  "version": "0.2.2",
+  "version": "0.3.0",
   "type": "module",
   "description": "Sell crawl access to AI training crawlers by the day over x402, settled by CoinPay. One middleware: 402 with an offer, a sales page with CLI instructions, signed passes, and a robots.txt that keeps search crawlers welcome.",
   "keywords": [

diff --git a/src/index.js b/src/index.js
@@ -29,7 +29,9 @@ export { buildOffer, decodePayment, expectedFor, METHODS, verifyAndSettle } from
  * or as an HTML sales page if it asked for HTML -- on every path but the few it
  * needs to read to comply. Paying the offer, at the sales page or on any 402'd
  * URL, returns a signed pass good for `passMinutes`, presented in `header` on
- * every request after that.
+ * every request after that. A crawler that wants longer buys more days at
+ * once: `?days=N` on the sales page quotes N terms, and a proof for N times
+ * the price — however it was asked for — buys a pass that lasts N terms.
  *
  * Framework-agnostic: `handle(request)` takes a Fetch `Request` and resolves to
  * a `Response` to send, or null to let the request through. The adapters in
@@ -42,7 +44,8 @@ export { buildOffer, decodePayment, expectedFor, METHODS, verifyAndSettle } from
  * @param {string} [options.payTo]                 EVM address that receives the USDC
  * @param {number} [options.priceCents=100]
  * @param {string} [options.currency='USD']
- * @param {number} [options.passMinutes=1440]          a day
+ * @param {number} [options.passMinutes=1440]          a day: the term one payment buys
+ * @param {number} [options.maxDays=30]            the most terms one proof may buy at once
  * @param {string} [options.header='x-crawl-pass']
  * @param {string} [options.path='/crawl']         the sales page
  * @param {string[]} [options.openPaths]           extra paths a refused crawler may read
@@ -65,22 +68,45 @@ export function createGateway(options = {}) {
   const denied = compileCidrs(o.denyCidrs);
   const isOpen = (path) => openPaths.some((p) => (p.endsWith('/') ? path.startsWith(p) : path === p));
 
-  const price = `${(o.priceCents / 100).toFixed(2)} ${o.currency}`;
+  const money = (cents) => `${(cents / 100).toFixed(2)} ${o.currency}`;
+  const price = money(o.priceCents);
   const buyUrl = `${o.siteUrl}${o.path}`;
 
-  const offer = () =>
+  /**
+   * How many terms a request is asking to buy: `?days=N`, clamped to
+   * [1, maxDays]. Anything unparseable is one day, which is what the offer
+   * always meant before there was a way to ask for more.
+   */
+  const daysFrom = (request) => {
+    const raw = new URL(request.url).searchParams.get('days');
+    const n = Number.parseInt(raw ?? '', 10);
+    if (!Number.isFinite(n) || n < 1) return 1;
+    return Math.min(n, o.maxDays);
+  };
+
+  /** The offer for `days` terms: the same entries, `days` times the price. */
+  const offer = (days = 1) =>
     enabled
       ? buildOffer({
           payTo: o.payTo,
-          priceCents: o.priceCents,
+          priceCents: o.priceCents * days,
           resource: buyUrl,
-          description: `${o.passMinutes} minutes of crawl access to ${o.siteUrl}`,
+          description: `${days * o.passMinutes} minutes of crawl access to ${o.siteUrl}${days > 1 ? ` (${days} × ${o.passMinutes})` : ''}`,
         })
       : { x402Version: 2, accepts: [] };
 
-  const receipt = (extra = {}) => ({
-    ...offer(),
-    pass: { price, minutes: o.passMinutes, header: o.header, buy: buyUrl },
+  const receipt = (days = 1, extra = {}) => ({
+    ...offer(days),
+    pass: {
+      price,
+      minutes: o.passMinutes,
+      days,
+      total: money(o.priceCents * days),
+      maxDays: o.maxDays,
+      header: o.header,
+      buy: days > 1 ? `${buyUrl}?days=${days}` : buyUrl,
+      buyDays: `${buyUrl}?days=<n>`,
+    },
     ...extra,
   });
 
@@ -96,12 +122,15 @@ export function createGateway(options = {}) {
   const html = (body, status) =>
     new Response(body, { status, headers: { 'content-type': 'text/html; charset=utf-8', ...noStore } });
 
-  const pageCtx = () => ({
+  const pageCtx = (days = 1) => ({
+    days,
+    total: money(o.priceCents * days),
     siteName: o.siteName,
     siteUrl: o.siteUrl,
     buyUrl,
     price,
     minutes: o.passMinutes,
+    maxDays: o.maxDays,
     header: o.header,
     enabled,
     offer: offer(),
@@ -129,14 +158,35 @@ export function createGateway(options = {}) {
   async function sell(request) {
     const ua = request.headers.get('user-agent') ?? '';
     const proofHeader = request.headers.get('x-payment');
+    const asked = daysFrom(request);
 
     if (proofHeader) {
-      if (!enabled) return json(receipt({ error: 'Payments are not switched on here.' }), 402);
+      if (!enabled) return json(receipt(asked, { error: 'Payments are not switched on here.' }), 402);
       const payment = decodePayment(proofHeader);
-      if (!payment) return json(receipt({ error: 'X-PAYMENT is not base64 JSON.' }), 402);
-      const current = offer();
-      const expected = expectedFor(payment, current);
-      if (!expected) return json(receipt({ error: 'Proof does not match an offered network.' }), 402);
+      if (!payment) return json(receipt(asked, { error: 'X-PAYMENT is not base64 JSON.' }), 402);
+      const unit = expectedFor(payment, offer(1));
+      if (!unit) return json(receipt(asked, { error: 'Proof does not match an offered network.' }), 402);
+
+      /*
+       * The money decides the term, not the URL. A proof is an authorization
+       * for an exact value, and the value the buyer signed is what CoinPay
+       * will move -- so the days it buys are read off the proof: a whole
+       * number of day-prices, at most maxDays. `?days=` shaped the offer the
+       * buyer read; if they then signed for a different multiple, they get
+       * what they paid for, and if they signed for something that is not a
+       * multiple they get nothing, before anyone is charged.
+       */
+      const days = daysPaid(paidValueOf(payment), unit.amount, o.maxDays);
+      if (!days) {
+        return json(
+          receipt(asked, {
+            error: `Pay a whole number of days: ${unit.amount} per day in the token's smallest unit, up to ${o.maxDays} days. Add ?days=<n> to ${buyUrl} for the offer.`,
+          }),
+          402,
+        );
+      }
+      const expected = expectedFor(payment, offer(days));
+      const term = days * o.passMinutes * 60;
 
       const now = Math.floor(Date.now() / 1000);
       const coinpay = { apiKey: o.coinpay.apiKey, baseUrl: o.coinpay.baseUrl, fetch: o.fetch };
@@ -145,7 +195,7 @@ export function createGateway(options = {}) {
       let expiresAt = null;
       let replayed = false;
       if (result.ok) {
-        expiresAt = now + o.passMinutes * 60;
+        expiresAt = now + term;
       } else if (result.replay) {
         /*
          * Paid once, lost the answer, asked again with the same proof. Answered
@@ -158,12 +208,12 @@ export function createGateway(options = {}) {
         const paid = await settleAgain(payment, coinpay);
         const validBefore = validBeforeOf(payment);
         if (paid && validBefore) {
-          expiresAt = Math.min(now + o.passMinutes * 60, validBefore + o.passMinutes * 60);
+          expiresAt = Math.min(now + term, validBefore + term);
           replayed = true;
         }
       }
       if (!expiresAt || expiresAt <= now) {
-        return json(receipt({ error: result.reason ?? 'Payment could not be settled.' }), 402);
+        return json(receipt(days, { error: result.reason ?? 'Payment could not be settled.' }), 402);
       }
 
       const ref = nonceOf(payment) ?? result.ref ?? null;
@@ -178,6 +228,8 @@ export function createGateway(options = {}) {
             expiresAt: expires,
             userAgent: ua,
             priceCents: o.priceCents,
+            days,
+            totalCents: o.priceCents * days,
             currency: o.currency,
           });
         } catch {
@@ -189,6 +241,8 @@ export function createGateway(options = {}) {
           ok: true,
           pass: pass.token,
           expires_at: expires,
+          days,
+          minutes: days * o.passMinutes,
           header: o.header,
           replayed,
           use: `curl -H "${o.header}: ${pass.token}" ${o.siteUrl}/`,
@@ -198,8 +252,8 @@ export function createGateway(options = {}) {
       );
     }
 
-    if (wantsHtml(request.headers.get('accept'))) return html(o.page(pageCtx()), 402);
-    return json(receipt({ error: `Payment required for training crawlers. Read ${buyUrl} for how.` }), 402);
+    if (wantsHtml(request.headers.get('accept'))) return html(o.page(pageCtx(asked)), 402);
+    return json(receipt(asked, { error: `Payment required for training crawlers. Read ${buyUrl} for how.` }), 402);
   }
 
   /**
@@ -253,6 +307,42 @@ export function createGateway(options = {}) {
 /** Whether the caller would rather read a page than a JSON offer. */
 export const wantsHtml = (accept = '') => String(accept ?? '').toLowerCase().includes('text/html');
 
+/** The value a proof authorizes, in the token's smallest unit, or null. */
+export function paidValueOf(payment) {
+  const raw = payment?.payload?.authorization?.value;
+  if (raw === undefined || raw === null || raw === '') return null;
+  try {
+    const value = BigInt(raw);
+    return value > 0n ? value : null;
+  } catch {
+    return null;
+  }
+}
+
+/**
+ * How many terms a paid value buys at `unit` per term: a whole number in
+ * [1, maxDays], or 0 when it is not one. Integer arithmetic on the smallest
+ * unit, so a price that is not a round number of cents still divides exactly.
+ *
+ * @param {bigint|null} value
+ * @param {string|number|bigint} unit
+ * @param {number} maxDays
+ * @returns {number}
+ */
+export function daysPaid(value, unit, maxDays) {
+  if (value === null) return 0;
+  let per;
+  try {
+    per = BigInt(unit);
+  } catch {
+    return 0;
+  }
+  if (per <= 0n || value % per !== 0n) return 0;
+  const days = value / per;
+  if (days < 1n || days > BigInt(maxDays)) return 0;
+  return Number(days);
+}
+
 function normalise(options) {
   const siteUrl = String(options.siteUrl ?? '').replace(/\/+$/, '');
   if (!siteUrl) throw new Error('createGateway needs siteUrl');
@@ -268,6 +358,7 @@ function normalise(options) {
     priceCents: Number.isFinite(options.priceCents) ? options.priceCents : 100,
     currency: options.currency ?? 'USD',
     passMinutes: Number.isFinite(options.passMinutes) && options.passMinutes > 0 ? options.passMinutes : 1440,
+    maxDays: Number.isInteger(options.maxDays) && options.maxDays >= 1 ? options.maxDays : 30,
     header: String(options.header ?? 'x-crawl-pass').toLowerCase(),
     path: options.path ?? '/crawl',
     openPaths: options.openPaths ?? [],

diff --git a/src/page.js b/src/page.js
@@ -55,6 +55,9 @@ export function renderPage(ctx) {
     training = [],
     retrieval = [],
     contact,
+    days = 1,
+    total = price,
+    maxDays = 30,
   } = ctx;
   const window =
     minutes === 1440
@@ -82,7 +85,12 @@ export function renderPage(ctx) {
 <h1>Training crawlers pay for access here.</h1>
 <p class="mut">People read <a href="${esc(siteUrl)}">${esc(siteName)}</a> free. So do search engines and the retrieval crawlers behind AI answers, because they send readers back. A crawler that copies pages into a training corpus sends nobody back, so it pays for the time it spends.</p>
 
-<div class="price">${esc(price)} <span class="mut" style="font-size:1rem;font-weight:400">for ${esc(window)} of requests</span></div>
+<div class="price">${esc(days > 1 ? total : price)} <span class="mut" style="font-size:1rem;font-weight:400">for ${esc(days > 1 ? `${days} × ${window}` : window)} of requests</span></div>
+${
+  days > 1
+    ? `<p class="mut">This offer is for ${days} days at ${esc(price)} a day. The plain page at <code>${esc(buyUrl)}</code> quotes one.</p>`
+    : `<p class="mut">Want longer? Add <code>?days=&lt;n&gt;</code> to this URL for an offer of up to ${maxDays} days at ${esc(price)} a day, or simply pay a whole multiple of the price: the pass lasts as many days as you paid for.</p>`
+}
 ${
   enabled
     ? ''
@@ -93,13 +101,15 @@ ${
 <ol>
   <li>Any page you fetch answers <code>402 Payment Required</code>. This page, fetched with <code>Accept: application/json</code>, returns the x402 offer: USDC, <code>exact</code> scheme, on ${esc(networks || 'Base, Polygon or Ethereum')}.</li>
   <li>Sign the payment and retry with the proof in an <code>X-PAYMENT</code> header. The response is a JSON receipt carrying a pass.</li>
-  <li>Send the pass in <code>${esc(header)}</code> on every request for the next ${esc(window)}. When it expires, buy another. The sale is the pass, not the page: fetch the page again with the pass.</li>
+  <li>Send the pass in <code>${esc(header)}</code> on every request until it expires — ${esc(window)} per day paid, so a proof for three times the price buys three. When it expires, buy another. The sale is the pass, not the page: fetch the page again with the pass.</li>
 </ol>
 
 <h2>Pay with the CoinPay CLI</h2>
 <p>Settlement is by CoinPay: the buyer's USDC goes straight to the site's wallet and CoinPay's relayer pays the gas, so you need USDC and nothing else.</p>
 <pre><code>npm install -g @profullstack/coinpay
-coinpay x402 pay ${esc(buyUrl)} --output pass.json</code></pre>
+coinpay x402 pay ${esc(buyUrl)} --output pass.json
+# or a week at once:
+coinpay x402 pay "${esc(buyUrl)}?days=7" --output pass.json</code></pre>
 <p>The command fetches this page, reads the offer, opens a browser tab to approve the payment with the CoinPay Wallet extension or any EIP-6963 wallet (MetaMask, Rabby, Coinbase Wallet), and writes the receipt to <code>pass.json</code>. Then:</p>
 <pre><code>PASS=$(node -p "require('./pass.json').pass")
 curl -H "${esc(header)}: $PASS" ${esc(siteUrl)}/</code></pre>
@@ -109,7 +119,8 @@ curl -H "${esc(header)}: $PASS" ${esc(siteUrl)}/</code></pre>
 # 402 with { "x402Version": 2, "accepts": [ ... ] }
 # sign an EIP-3009 transferWithAuthorization for one entry, then:
 curl -sS -H "X-PAYMENT: &lt;base64 proof&gt;" ${esc(buyUrl)}
-# 200 with { "ok": true, "pass": "cp_...", "expires_at": "...", "header": "${esc(header)}" }</code></pre>
+# 200 with { "ok": true, "pass": "cp_...", "expires_at": "...", "days": 1, "header": "${esc(header)}" }</code></pre>
+<p class="mut">The days a proof buys are read off the value it authorizes: a whole multiple of the one-day amount, up to ${maxDays}. <code>?days=&lt;n&gt;</code> only changes what the offer quotes, so a standard client that pays exactly what is asked gets <em>n</em> days.</p>
 <p class="mut">The proof is x402 v2 in CoinPay's dialect: <code>{ x402Version: 2, scheme: "exact", network: "&lt;CAIP-2&gt;", payload: { signature, authorization } }</code>, base64-encoded. A proof is single-use; retrying with the same one returns the same pass, not a second charge.</p>
 
 <h2>Who pays and who does not</h2>