fix: self-service signup, unified key store, persistent data volume

- Added /v1/signup/free endpoint for instant API key provisioning
- Built unified key store (services/keys.ts) with file-based persistence
- Refactored auth middleware to use key store (no more hardcoded env keys)
- Refactored usage middleware to check key tier from store
- Updated billing to use key store for Pro key provisioning
- Landing page: replaced mailto: link with signup modal
- Landing page: Pro checkout button now properly calls /v1/billing/checkout
- Added Docker volume for persistent key storage
- Success page now renders HTML instead of raw JSON
- Tested: signup → key → PDF generation works end-to-end

src/index.ts

@@ -6,22 +6,27 @@ import rateLimit from "express-rate-limit";
 import { convertRouter } from "./routes/convert.js";
 import { templatesRouter } from "./routes/templates.js";
 import { healthRouter } from "./routes/health.js";
+import { signupRouter } from "./routes/signup.js";
+import { billingRouter } from "./routes/billing.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";
-import { billingRouter } from "./routes/billing.js";
+import { loadKeys, getAllKeys } from "./services/keys.js";
 
 const app = express();
 const PORT = parseInt(process.env.PORT || "3100", 10);
 
+// Load API keys from persistent store
+loadKeys();
+
 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/*" }));
 
-// Rate limiting: 100 req/min for free tier
+// Rate limiting
 const limiter = rateLimit({
   windowMs: 60_000,
   max: 100,
@@ -30,17 +35,16 @@ const limiter = rateLimit({
 });
 app.use(limiter);
 
-// Public
+// Public routes
 app.use("/health", healthRouter);
+app.use("/v1/signup", signupRouter);
+app.use("/v1/billing", billingRouter);
 
-// Authenticated
+// Authenticated routes
 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)
+// Admin: usage stats
 app.get("/v1/usage", authMiddleware, (_req, res) => {
   res.json(getUsageStats());
 });
@@ -49,24 +53,26 @@ app.get("/v1/usage", authMiddleware, (_req, res) => {
 const __dirname = path.dirname(fileURLToPath(import.meta.url));
 app.use(express.static(path.join(__dirname, "../public")));
 
-// API root (for programmatic discovery)
+// API root
 app.get("/api", (_req, res) => {
   res.json({
     name: "DocFast API",
-    version: "0.1.0",
-    docs: "/health",
+    version: "0.2.0",
     endpoints: [
+      "POST /v1/signup/free — Get a free API key",
       "POST /v1/convert/html",
       "POST /v1/convert/markdown",
       "POST /v1/convert/url",
       "POST /v1/templates/:id/render",
       "GET  /v1/templates",
+      "POST /v1/billing/checkout — Start Pro subscription",
     ],
   });
 });
 
 async function start() {
   await initBrowser();
+  console.log(`Loaded ${getAllKeys().length} API keys`);
   app.listen(PORT, () => console.log(`DocFast API running on :${PORT}`));
 
   const shutdown = async () => {