Add Stripe billing integration + update free tier to 100 PDFs/mo

docker-compose.yml

@@ -9,5 +9,9 @@ services:
       - API_KEYS=${API_KEYS}
       - PORT=3100
       - NODE_ENV=production
+      - STRIPE_SECRET_KEY=${STRIPE_SECRET_KEY}
+      - STRIPE_WEBHOOK_SECRET=${STRIPE_WEBHOOK_SECRET}
+      - BASE_URL=${BASE_URL:-https://docfast.dev}
+      - PRO_KEYS=${PRO_KEYS}
     mem_limit: 512m
     cpus: 1.0

package-lock.json

@@ -13,7 +13,8 @@
         "helmet": "^8.0.0",
         "marked": "^15.0.0",
         "nanoid": "^5.0.0",
-        "puppeteer": "^24.0.0"
+        "puppeteer": "^24.0.0",
+        "stripe": "^20.3.1"
       },
       "devDependencies": {
         "@types/express": "^5.0.0",
@@ -3377,6 +3378,23 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/stripe": {
+      "version": "20.3.1",
+      "resolved": "https://registry.npmjs.org/stripe/-/stripe-20.3.1.tgz",
+      "integrity": "sha512-k990yOT5G5rhX3XluRPw5Y8RLdJDW4dzQ29wWT66piHrbnM2KyamJ1dKgPsw4HzGHRWjDiSSdcI2WdxQUPV3aQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=16"
+      },
+      "peerDependencies": {
+        "@types/node": ">=16"
+      },
+      "peerDependenciesMeta": {
+        "@types/node": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/tar-fs": {
       "version": "3.1.1",
       "resolved": "https://registry.npmjs.org/tar-fs/-/tar-fs-3.1.1.tgz",

package.json

@@ -11,17 +11,18 @@
   },
   "dependencies": {
     "express": "^4.21.0",
-    "marked": "^15.0.0",
-    "puppeteer": "^24.0.0",
-    "nanoid": "^5.0.0",
+    "express-rate-limit": "^7.5.0",
     "helmet": "^8.0.0",
-    "express-rate-limit": "^7.5.0"
+    "marked": "^15.0.0",
+    "nanoid": "^5.0.0",
+    "puppeteer": "^24.0.0",
+    "stripe": "^20.3.1"
   },
   "devDependencies": {
-    "typescript": "^5.7.0",
-    "tsx": "^4.19.0",
     "@types/express": "^5.0.0",
     "@types/node": "^22.0.0",
+    "tsx": "^4.19.0",
+    "typescript": "^5.7.0",
     "vitest": "^3.0.0"
   },
   "type": "module"

public/index.html

@@ -171,7 +171,7 @@ footer { padding: 40px 0; text-align: center; color: var(--muted); font-size: 0.
           <li>All templates</li>
           <li>Community support</li>
         </ul>
-        <a href="#" class="btn btn-secondary" style="width:100%">Start Free</a>
+        <a href="mailto:hello@docfast.dev?subject=Free API Key" class="btn btn-secondary" style="width:100%">Get Free Key</a>
       </div>
       <div class="price-card featured">
         <h3>Pro</h3>
@@ -183,7 +183,7 @@ footer { padding: 40px 0; text-align: center; color: var(--muted); font-size: 0.
           <li>Priority support</li>
           <li>Custom templates</li>
         </ul>
-        <a href="#" class="btn btn-primary" style="width:100%">Get Started</a>
+        <a href="#" class="btn btn-primary" style="width:100%" onclick="checkout(event)">Get Started</a>
       </div>
     </div>
   </div>
@@ -195,5 +195,18 @@ footer { padding: 40px 0; text-align: center; color: var(--muted); font-size: 0.
   </div>
 </footer>
 
+<script>
+async function checkout(e) {
+  e.preventDefault();
+  try {
+    const res = await fetch('/v1/billing/checkout', { method: 'POST' });
+    const data = await res.json();
+    if (data.url) window.location.href = data.url;
+    else alert('Something went wrong. Please try again.');
+  } catch (err) {
+    alert('Something went wrong. Please try again.');
+  }
+}
+</script>
 </body>
 </html>

src/index.ts

@@ -10,11 +10,14 @@ import { authMiddleware } from "./middleware/auth.js";
 import { usageMiddleware } from "./middleware/usage.js";
 import { getUsageStats } from "./middleware/usage.js";
 import { initBrowser, closeBrowser } from "./services/browser.js";
+import { billingRouter } from "./routes/billing.js";
 
 const app = express();
 const PORT = parseInt(process.env.PORT || "3100", 10);
 
 app.use(helmet());
+// Raw body for Stripe webhook signature verification
+app.use("/v1/billing/webhook", express.raw({ type: "application/json" }));
 app.use(express.json({ limit: "2mb" }));
 app.use(express.text({ limit: "2mb", type: "text/*" }));
 
@@ -34,6 +37,9 @@ app.use("/health", healthRouter);
 app.use("/v1/convert", authMiddleware, usageMiddleware, convertRouter);
 app.use("/v1/templates", authMiddleware, usageMiddleware, templatesRouter);
 
+// Billing (public — Stripe handles auth)
+app.use("/v1/billing", billingRouter);
+
 // Admin: usage stats (protected by auth)
 app.get("/v1/usage", authMiddleware, (_req, res) => {
   res.json(getUsageStats());

src/middleware/usage.ts

@@ -8,7 +8,9 @@ interface UsageRecord {
 // In-memory usage tracking (replace with Redis/DB for production)
 const usage = new Map<string, UsageRecord>();
 
-const FREE_TIER_LIMIT = 50; // 50 PDFs/month for free tier
+const FREE_TIER_LIMIT = 100; // 100 PDFs/month for free tier
+import { isProKey as isRuntimeProKey } from "../routes/billing.js";
+
 const PRO_KEYS = new Set(
   (process.env.PRO_KEYS || "").split(",").map((k) => k.trim()).filter(Boolean)
 );
@@ -26,8 +28,8 @@ export function usageMiddleware(
   const key = req.headers.authorization?.slice(7) || "unknown";
   const monthKey = getMonthKey();
 
-  // Pro keys have no limit
-  if (PRO_KEYS.has(key)) {
+  // Pro keys have no limit (env-configured or runtime-provisioned via Stripe)
+  if (PRO_KEYS.has(key) || isRuntimeProKey(key)) {
     trackUsage(key, monthKey);
     next();
     return;

src/routes/billing.ts

@@ -0,0 +1,182 @@
+import { Router, Request, Response } from "express";
+import Stripe from "stripe";
+import { nanoid } from "nanoid";
+
+const stripe = new Stripe(process.env.STRIPE_SECRET_KEY || "", {
+  apiVersion: "2025-01-27.acacia" as any,
+});
+
+const router = Router();
+
+// In-memory store of customer → API key mappings
+// In production, this would be a database
+const customerKeys = new Map<string, string>();
+
+// Create a Stripe Checkout session for Pro subscription
+router.post("/checkout", async (_req: Request, res: Response) => {
+  try {
+    // Find or create the Pro plan product+price
+    const priceId = await getOrCreateProPrice();
+
+    const session = await stripe.checkout.sessions.create({
+      mode: "subscription",
+      payment_method_types: ["card"],
+      line_items: [{ price: priceId, quantity: 1 }],
+      success_url: `${process.env.BASE_URL || "https://docfast.dev"}/billing/success?session_id={CHECKOUT_SESSION_ID}`,
+      cancel_url: `${process.env.BASE_URL || "https://docfast.dev"}/pricing`,
+    });
+
+    res.json({ url: session.url });
+  } catch (err: any) {
+    console.error("Checkout error:", err.message);
+    res.status(500).json({ error: "Failed to create checkout session" });
+  }
+});
+
+// Success page — retrieve API key after checkout
+router.get("/success", async (req: Request, res: Response) => {
+  const sessionId = req.query.session_id as string;
+  if (!sessionId) {
+    res.status(400).json({ error: "Missing session_id" });
+    return;
+  }
+
+  try {
+    const session = await stripe.checkout.sessions.retrieve(sessionId);
+    const customerId = session.customer as string;
+
+    if (!customerId) {
+      res.status(400).json({ error: "No customer found" });
+      return;
+    }
+
+    // Generate or retrieve API key for this customer
+    let apiKey = customerKeys.get(customerId);
+    if (!apiKey) {
+      apiKey = `df_pro_${nanoid(32)}`;
+      customerKeys.set(customerId, apiKey);
+      // Add to PRO_KEYS runtime set
+      addProKey(apiKey);
+    }
+
+    res.json({
+      message: "Welcome to DocFast Pro! 🎉",
+      apiKey,
+      docs: "/api",
+      note: "Save this API key — it won't be shown again.",
+    });
+  } catch (err: any) {
+    console.error("Success page error:", err.message);
+    res.status(500).json({ error: "Failed to retrieve session" });
+  }
+});
+
+// Stripe webhook for subscription lifecycle events
+router.post(
+  "/webhook",
+  // Raw body needed for signature verification
+  async (req: Request, res: Response) => {
+    const sig = req.headers["stripe-signature"] as string;
+    const webhookSecret = process.env.STRIPE_WEBHOOK_SECRET;
+
+    let event: Stripe.Event;
+
+    if (webhookSecret && sig) {
+      try {
+        event = stripe.webhooks.constructEvent(
+          req.body,
+          sig,
+          webhookSecret
+        );
+      } catch (err: any) {
+        console.error("Webhook signature verification failed:", err.message);
+        res.status(400).json({ error: "Invalid signature" });
+        return;
+      }
+    } else {
+      // No webhook secret configured — accept all events (dev mode)
+      event = req.body as Stripe.Event;
+    }
+
+    switch (event.type) {
+      case "customer.subscription.deleted": {
+        const sub = event.data.object as Stripe.Subscription;
+        const customerId = sub.customer as string;
+        const key = customerKeys.get(customerId);
+        if (key) {
+          removeProKey(key);
+          customerKeys.delete(customerId);
+          console.log(`Subscription cancelled for ${customerId}, key revoked`);
+        }
+        break;
+      }
+      default:
+        // Ignore other events
+        break;
+    }
+
+    res.json({ received: true });
+  }
+);
+
+// --- Pro key management ---
+// These integrate with the usage middleware's PRO_KEYS set
+const runtimeProKeys = new Set<string>();
+
+export function addProKey(key: string): void {
+  runtimeProKeys.add(key);
+}
+
+export function removeProKey(key: string): void {
+  runtimeProKeys.delete(key);
+}
+
+export function isProKey(key: string): boolean {
+  return runtimeProKeys.has(key);
+}
+
+// --- Price management ---
+let cachedPriceId: string | null = null;
+
+async function getOrCreateProPrice(): Promise<string> {
+  if (cachedPriceId) return cachedPriceId;
+
+  // Search for existing product
+  const products = await stripe.products.search({
+    query: "name:'DocFast Pro'",
+  });
+
+  let productId: string;
+
+  if (products.data.length > 0) {
+    productId = products.data[0].id;
+    // Find active price
+    const prices = await stripe.prices.list({
+      product: productId,
+      active: true,
+      limit: 1,
+    });
+    if (prices.data.length > 0) {
+      cachedPriceId = prices.data[0].id;
+      return cachedPriceId;
+    }
+  } else {
+    const product = await stripe.products.create({
+      name: "DocFast Pro",
+      description: "Unlimited PDF conversions via API. HTML, Markdown, and URL to PDF.",
+    });
+    productId = product.id;
+  }
+
+  const price = await stripe.prices.create({
+    product: productId,
+    unit_amount: 900, // $9.00
+    currency: "usd",
+    recurring: { interval: "month" },
+  });
+
+  cachedPriceId = price.id;
+  return cachedPriceId;
+}
+
+export { router as billingRouter };