Add URL→PDF endpoint, usage tracking middleware, free tier limits

package.json

@@ -23,5 +23,6 @@
     "@types/express": "^5.0.0",
     "@types/node": "^22.0.0",
     "vitest": "^3.0.0"
-  }
+  },
+  "type": "module"
 }

src/index.ts

@@ -7,6 +7,8 @@ import { convertRouter } from "./routes/convert.js";
 import { templatesRouter } from "./routes/templates.js";
 import { healthRouter } from "./routes/health.js";
 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";
 
 const app = express();
@@ -29,8 +31,13 @@ app.use(limiter);
 app.use("/health", healthRouter);
 
 // Authenticated
-app.use("/v1/convert", authMiddleware, convertRouter);
-app.use("/v1/templates", authMiddleware, templatesRouter);
+app.use("/v1/convert", authMiddleware, usageMiddleware, convertRouter);
+app.use("/v1/templates", authMiddleware, usageMiddleware, templatesRouter);
+
+// Admin: usage stats (protected by auth)
+app.get("/v1/usage", authMiddleware, (_req, res) => {
+  res.json(getUsageStats());
+});
 
 // Landing page
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
@@ -45,6 +52,7 @@ app.get("/api", (_req, res) => {
     endpoints: [
       "POST /v1/convert/html",
       "POST /v1/convert/markdown",
+      "POST /v1/convert/url",
       "POST /v1/templates/:id/render",
       "GET  /v1/templates",
     ],

src/middleware/usage.ts

@@ -0,0 +1,68 @@
+import { Request, Response, NextFunction } from "express";
+
+interface UsageRecord {
+  count: number;
+  monthKey: string;
+}
+
+// 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 PRO_KEYS = new Set(
+  (process.env.PRO_KEYS || "").split(",").map((k) => k.trim()).filter(Boolean)
+);
+
+function getMonthKey(): string {
+  const d = new Date();
+  return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, "0")}`;
+}
+
+export function usageMiddleware(
+  req: Request,
+  res: Response,
+  next: NextFunction
+): void {
+  const key = req.headers.authorization?.slice(7) || "unknown";
+  const monthKey = getMonthKey();
+
+  // Pro keys have no limit
+  if (PRO_KEYS.has(key)) {
+    trackUsage(key, monthKey);
+    next();
+    return;
+  }
+
+  // Free tier limit check
+  const record = usage.get(key);
+  if (record && record.monthKey === monthKey && record.count >= FREE_TIER_LIMIT) {
+    res.status(429).json({
+      error: "Free tier limit reached",
+      limit: FREE_TIER_LIMIT,
+      used: record.count,
+      upgrade: "Upgrade to Pro for unlimited conversions: https://docfast.dev/pricing",
+    });
+    return;
+  }
+
+  trackUsage(key, monthKey);
+  next();
+}
+
+function trackUsage(key: string, monthKey: string): void {
+  const record = usage.get(key);
+  if (!record || record.monthKey !== monthKey) {
+    usage.set(key, { count: 1, monthKey });
+  } else {
+    record.count++;
+  }
+}
+
+export function getUsageStats(): Record<string, { count: number; month: string }> {
+  const stats: Record<string, { count: number; month: string }> = {};
+  for (const [key, record] of usage) {
+    const masked = key.slice(0, 8) + "...";
+    stats[masked] = { count: record.count, month: record.monthKey };
+  }
+  return stats;
+}

src/routes/convert.ts

@@ -1,5 +1,5 @@
 import { Router, Request, Response } from "express";
-import { renderPdf } from "../services/browser.js";
+import { renderPdf, renderUrlPdf } from "../services/browser.js";
 import { markdownToHtml, wrapHtml } from "../services/markdown.js";
 
 export const convertRouter = Router();
@@ -76,3 +76,43 @@ convertRouter.post("/markdown", async (req: Request, res: Response) => {
     res.status(500).json({ error: "PDF generation failed", detail: err.message });
   }
 });
+
+// POST /v1/convert/url
+convertRouter.post("/url", async (req: Request, res: Response) => {
+  try {
+    const body = req.body as { url?: string; format?: string; landscape?: boolean; margin?: any; printBackground?: boolean; waitUntil?: string; filename?: string };
+
+    if (!body.url) {
+      res.status(400).json({ error: "Missing 'url' field" });
+      return;
+    }
+
+    // Basic URL validation
+    try {
+      const parsed = new URL(body.url);
+      if (!["http:", "https:"].includes(parsed.protocol)) {
+        res.status(400).json({ error: "Only http/https URLs are supported" });
+        return;
+      }
+    } catch {
+      res.status(400).json({ error: "Invalid URL" });
+      return;
+    }
+
+    const pdf = await renderUrlPdf(body.url, {
+      format: body.format,
+      landscape: body.landscape,
+      margin: body.margin,
+      printBackground: body.printBackground,
+      waitUntil: body.waitUntil,
+    });
+
+    const filename = body.filename || "page.pdf";
+    res.setHeader("Content-Type", "application/pdf");
+    res.setHeader("Content-Disposition", `inline; filename="${filename}"`);
+    res.send(pdf);
+  } catch (err: any) {
+    console.error("Convert URL error:", err);
+    res.status(500).json({ error: "PDF generation failed", detail: err.message });
+  }
+});

src/services/browser.ts

@@ -52,3 +52,40 @@ export async function renderPdf(
     await page.close();
   }
 }
+
+export async function renderUrlPdf(
+  url: string,
+  options: {
+    format?: string;
+    landscape?: boolean;
+    margin?: { top?: string; right?: string; bottom?: string; left?: string };
+    printBackground?: boolean;
+    waitUntil?: string;
+  } = {}
+): Promise<Buffer> {
+  if (!browser) throw new Error("Browser not initialized");
+
+  const page: Page = await browser.newPage();
+  try {
+    await page.goto(url, {
+      waitUntil: (options.waitUntil as any) || "networkidle0",
+      timeout: 30_000,
+    });
+
+    const pdf = await page.pdf({
+      format: (options.format as any) || "A4",
+      landscape: options.landscape || false,
+      printBackground: options.printBackground !== false,
+      margin: options.margin || {
+        top: "20mm",
+        right: "15mm",
+        bottom: "20mm",
+        left: "15mm",
+      },
+    });
+
+    return Buffer.from(pdf);
+  } finally {
+    await page.close();
+  }
+}