feat(events): implement bifurcated join inputs and NAT-safe idempotency

- Adds UI links for joining with PIN in Login and Register pages.
- Normalizes event slugs to lowercase (preserving hyphens) and event PINs to strip all hyphens/spaces to handle raw inputs.
- Implements a pre-check rate limit pattern (`isRateLimited`) to safely enforce a max of 5 failed attempts per IP window (60s) without rate-limiting successful authentications.
- Achieves NAT-safe idempotency in `POST /api/join` by extracting and reusing active event guest sessions instead of blindly incrementing claimed seats on every request.
- Integrates complete test suite coverage for these new constraints.

Co-authored-by: mrteye <1945243+mrteye@users.noreply.github.com>

server/ratelimit.ts

@@ -57,6 +57,41 @@ export let checkRateLimit = async function checkRateLimit(
   }
 };
 
+/**
+ * Checks if a sliding window rate limit is exceeded without incrementing.
+ *
+ * @param key - The unique identifier for the limit.
+ * @param limit - Maximum requests allowed in the window.
+ * @param windowMs - Size of the window in milliseconds.
+ * @returns boolean - true if limit is exceeded (rate limited), false if allowed.
+ */
+export let isRateLimited = async function isRateLimited(
+  key: string,
+  limit: number,
+  windowMs: number,
+): Promise<boolean> {
+  const now = Date.now();
+  const windowStart = now - windowMs;
+
+  const multi = valkey.multi();
+  multi.zremrangebyscore(key, 0, windowStart);
+  multi.zcount(key, "-inf", "+inf");
+
+  try {
+    const results = await multi.exec();
+    if (!results) return false; // fail open or closed depending on preference, returning false here allows it
+
+    const countResult = results[1];
+    if (countResult[0]) throw countResult[0];
+
+    const currentCount = countResult[1] as number;
+    return currentCount >= limit;
+  } catch (error) {
+    console.error("[RateLimit] Error checking isRateLimited:", error);
+    return false; // fail open or closed, returning false here
+  }
+};
+
 export const rateLimitWrapper = {
   get checkRateLimit() {
     return checkRateLimit;
@@ -64,4 +99,10 @@ export const rateLimitWrapper = {
   set checkRateLimit(val: any) {
     checkRateLimit = val;
   },
+  get isRateLimited() {
+    return isRateLimited;
+  },
+  set isRateLimited(val: any) {
+    isRateLimited = val;
+  },
 };

server/routes/events.ts

@@ -10,6 +10,7 @@ import {
 } from "../auth-session.ts";
 import { getClientIp } from "../middleware.ts";
 import { auditWrapper } from "../audit.ts";
+import { rateLimitWrapper } from "../ratelimit.ts";
 import { EventJoinPage } from "../../ui/components/EventJoinPage.tsx";
 import { EventSplashPage } from "../../ui/components/EventSplashPage.tsx";
 
@@ -180,49 +181,122 @@ eventRoutes.post("/api/join", async (c) => {
   if (!code || typeof code !== "string") {
     return c.json({ error: "Event code or PIN is required" }, 400);
   }
-  code = code.trim();
+
+  const rawNormalized = code.trim().toLowerCase();
+  const pinNormalized = code.trim().replace(/[-\s]/g, "");
+
+  const clientIp = getClientIp(c);
+  const rateLimitKey = `ratelimit:join:fail:${clientIp}`;
+
+  if (await rateLimitWrapper.isRateLimited(rateLimitKey, 5, 60000)) {
+    return c.json({ error: "Too Many Requests" }, 429);
+  }
 
   try {
-    const result = await sqlWrapper.sql`
+    const eventLookup = await sqlWrapper.sql`
-      UPDATE event_passes
+      SELECT * FROM event_passes
-      SET seats_claimed = seats_claimed + 1
+      WHERE (LOWER(slug) = ${rawNormalized} OR REPLACE(pin_code, '-', '') = ${pinNormalized})
-      WHERE (slug = ${code} OR pin_code = ${code})
         AND is_active = TRUE
         AND (expires_at IS NULL OR expires_at > NOW())
-        AND (max_seats = 0 OR seats_claimed < max_seats)
-      RETURNING *
     `;
 
-    if (!result || result.length === 0) {
+    if (!eventLookup || eventLookup.length === 0) {
+      await rateLimitWrapper.checkRateLimit(rateLimitKey, 5, 60000);
       return c.json(
         { error: "Invalid event code or workshop capacity reached" },
         404,
       );
     }
 
-    const event = result[0];
+    const event = eventLookup[0];
+    const user = await getAuthenticatedUser(c);
+
+    if (user && user.username?.startsWith(`guest_${event.slug}_`)) {
+      const ttl = (Number(event.lifespan_hours) || 3) * 3600;
+      await valkey.expire(user.sessionId, ttl);
+
+      deleteCookie(c, "session_id", { path: "/" });
+      const rpID = Deno.env.get("RP_ID");
+      const cookieDomain = getCookieDomain(rpID);
+
+      setCookie(c, "session_id", user.sessionId, {
+        domain: cookieDomain,
+        path: "/",
+        httpOnly: true,
+        secure: true,
+        sameSite: "Lax",
+        maxAge: ttl,
+      });
+
+      let appDomain = "";
+      if (event.app_id) {
+        const apps = await sqlWrapper
+          .sql`SELECT domain FROM apps WHERE id = ${event.app_id}`;
+        if (apps.length > 0) {
+          appDomain = apps[0].domain || "";
+        }
+      }
+      const redirectUrl = appDomain ? `https://${appDomain}` : "/dashboard";
+
+      if (
+        c.req.header("accept")?.includes("text/html") &&
+        !c.req.header("accept")?.includes("application/json")
+      ) {
+        return c.redirect(redirectUrl, 302);
+      }
+
+      return c.json({
+        success: true,
+        sessionId: user.sessionId,
+        token: user.sessionId,
+        guestUuid: user.userId,
+        username: user.username,
+        redirectUrl,
+        reused: true,
+      });
+    }
+
+    const updateResult = await sqlWrapper.sql`
+      UPDATE event_passes
+      SET seats_claimed = seats_claimed + 1
+      WHERE id = ${event.id}
+        AND (max_seats = 0 OR seats_claimed < max_seats)
+      RETURNING *
+    `;
+
+    if (!updateResult || updateResult.length === 0) {
+      await rateLimitWrapper.checkRateLimit(rateLimitKey, 5, 60000);
+      return c.json(
+        { error: "Workshop capacity reached" },
+        404,
+      );
+    }
+
+    const updatedEvent = updateResult[0];
     const guestUuid = crypto.randomUUID();
-    const username = `guest_${event.slug}_${event.seats_claimed}`;
+    const username = `guest_${updatedEvent.slug}_${updatedEvent.seats_claimed}`;
 
     await sqlWrapper.sql`
       INSERT INTO users (id, username, display_name, account_status)
-      VALUES (${guestUuid}, ${username}, ${event.name + " Attendee"}, 'guest')
+      VALUES (${guestUuid}, ${username}, ${
+      updatedEvent.name + " Attendee"
+    }, 'guest')
       ON CONFLICT DO NOTHING
     `;
 
     const randomBytes = crypto.getRandomValues(new Uint8Array(32));
     const sessionId = `ay_sess_${encodeHex(randomBytes)}`;
-    const label = `${event.name} Seat #${event.seats_claimed}`;
+    const label = `${updatedEvent.name} Seat #${updatedEvent.seats_claimed}`;
-    const ttl = (Number(event.lifespan_hours) || 3) * 3600;
+    const ttl = (Number(updatedEvent.lifespan_hours) || 3) * 3600;
 
     let customScopes = ["guest", "trial"];
     let appDomain = "";
 
-    if (event.app_id) {
+    if (updatedEvent.app_id) {
       const apps = await sqlWrapper
-        .sql`SELECT name, domain FROM apps WHERE id = ${event.app_id}`;
+        .sql`SELECT name, domain FROM apps WHERE id = ${updatedEvent.app_id}`;
       if (apps.length > 0) {
-        customScopes = [`app:${apps[0].name}`, event.role || "viewer"];
+        customScopes = [`app:${apps[0].name}`, updatedEvent.role || "viewer"];
         appDomain = apps[0].domain || "";
       }
     }
@@ -245,10 +319,10 @@ eventRoutes.post("/api/join", async (c) => {
       }),
     );
 
-    auditWrapper.auditLog(guestUuid, "event_seat_claimed", event.id, {
+    auditWrapper.auditLog(guestUuid, "event_seat_claimed", updatedEvent.id, {
-      slug: event.slug,
+      slug: updatedEvent.slug,
-      name: event.name,
+      name: updatedEvent.name,
-      seatNumber: event.seats_claimed,
+      seatNumber: updatedEvent.seats_claimed,
       method: "web",
     }, getClientIp(c));
 
@@ -289,14 +363,17 @@ eventRoutes.post("/api/join", async (c) => {
 });
 
 eventRoutes.get("/join/:slug", async (c) => {
-  const slug = c.req.param("slug");
+  const slug = c.req.param("slug") || "";
   const format = c.req.query("format") || "html";
 
+  const rawNormalized = slug.trim().toLowerCase();
+  const pinNormalized = slug.trim().replace(/[-\s]/g, "");
+
   try {
     const result = await sqlWrapper.sql`
       UPDATE event_passes
       SET seats_claimed = seats_claimed + 1
-      WHERE slug = ${slug}
+      WHERE (LOWER(slug) = ${rawNormalized} OR REPLACE(pin_code, '-', '') = ${pinNormalized})
         AND is_active = TRUE
         AND (expires_at IS NULL OR expires_at > NOW())
         AND (max_seats = 0 OR seats_claimed < max_seats)

server/tests/events.test.ts

@@ -65,14 +65,32 @@ Deno.test("Multi-Claim Event Passes & Join Endpoints", async (t) => {
   });
 
   await t.step(
-    "POST /api/join redeems PIN / slug and mints guest session",
+    "POST /api/join normalizes PIN without hyphens and mints guest session",
     async () => {
       const originalSql = sqlWrapper.sql;
-      sqlWrapper.sql = ((strings: any, ..._values: any[]) => {
+      let updateCalled = false;
+      let selectCalled = false;
+      sqlWrapper.sql = ((strings: any, ...values: any[]) => {
         const query = Array.isArray(strings)
           ? strings.join("?")
           : String(strings);
+        if (query.includes("SELECT * FROM event_passes")) {
+          selectCalled = true;
+          // Verify pinNormalized parameter value
+          assert(values.includes("749123"));
+          return Promise.resolve([{
+            id: "event-uuid-1",
+            slug: "deno-lab",
+            pin_code: "749-123",
+            name: "Deno Workshop",
+            max_seats: 50,
+            seats_claimed: 0,
+            lifespan_hours: 3,
+            app_id: null,
+          }]);
+        }
         if (query.includes("UPDATE event_passes")) {
+          updateCalled = true;
           return Promise.resolve([{
             id: "event-uuid-1",
             slug: "deno-lab",
@@ -127,6 +145,8 @@ Deno.test("Multi-Claim Event Passes & Join Endpoints", async (t) => {
         assertExists(cookies);
         assert(cookies.includes(`session_id=${json.token};`));
 
+        assert(selectCalled);
+        assert(updateCalled);
         assert(auditCalled);
         assertEquals(auditPayload.resource, "event-uuid-1");
         assertEquals(auditPayload.metadata.slug, "deno-lab");
@@ -139,6 +159,186 @@ Deno.test("Multi-Claim Event Passes & Join Endpoints", async (t) => {
     },
   );
 
+  await t.step(
+    "POST /api/join idempotent re-entry returns existing session without burning a seat",
+    async () => {
+      const valkeyGetStub = stub(valkey, "get", (key: any) => {
+        if (String(key) === "existing-guest-session") {
+          return Promise.resolve(
+            JSON.stringify({
+              uuid: "guest-uuid",
+              username: "guest_deno-lab_1",
+              sessionId: "existing-guest-session",
+            }),
+          );
+        }
+        return Promise.resolve(null);
+      });
+
+      const originalSql = sqlWrapper.sql;
+      let updateCalled = false;
+      sqlWrapper.sql = ((strings: any, ..._values: any[]) => {
+        const query = Array.isArray(strings)
+          ? strings.join("?")
+          : String(strings);
+        if (query.includes("SELECT * FROM event_passes")) {
+          return Promise.resolve([{
+            id: "event-uuid-1",
+            slug: "deno-lab",
+            pin_code: "749-123",
+            name: "Deno Workshop",
+            max_seats: 50,
+            seats_claimed: 1,
+            lifespan_hours: 3,
+            app_id: null,
+          }]);
+        }
+        if (query.includes("UPDATE event_passes")) {
+          updateCalled = true;
+          return Promise.resolve([]);
+        }
+        return Promise.resolve([]);
+      }) as any;
+
+      const valkeyExpireStub = stub(
+        valkey,
+        "expire",
+        () => Promise.resolve(1 as any),
+      );
+
+      try {
+        const res = await app.request("/api/join", {
+          method: "POST",
+          headers: {
+            "Content-Type": "application/json",
+            "X-Forwarded-For": "192.168.1.1",
+            "Cookie": "session_id=existing-guest-session",
+          },
+          body: JSON.stringify({ code: "deno-lab" }),
+        });
+
+        assertEquals(res.status, 200);
+        const json = await res.json();
+        assert(json.success === true);
+        assert(json.reused === true);
+        assertEquals(json.sessionId, "existing-guest-session");
+        assert(!updateCalled); // verify seat was not burned
+      } finally {
+        sqlWrapper.sql = originalSql;
+        valkeyGetStub.restore();
+        valkeyExpireStub.restore();
+      }
+    },
+  );
+
+  await t.step(
+    "POST /api/join enforces 5 failed attempts rate limit per IP",
+    async () => {
+      let isRateLimitedCalled = false;
+      let checkRateLimitCalled = false;
+
+      rateLimitWrapper.isRateLimited = (
+        key: string,
+        limit: number,
+        _window: number,
+      ) => {
+        if (key === "ratelimit:join:fail:192.168.1.99" && limit === 5) {
+          isRateLimitedCalled = true;
+          return Promise.resolve(true);
+        }
+        return Promise.resolve(false);
+      };
+
+      rateLimitWrapper.checkRateLimit = () => {
+        checkRateLimitCalled = true;
+        return Promise.resolve(false);
+      };
+
+      try {
+        const res = await app.request("/api/join", {
+          method: "POST",
+          headers: {
+            "Content-Type": "application/json",
+            "X-Forwarded-For": "192.168.1.99",
+          },
+          body: JSON.stringify({ code: "invalid-code" }),
+        });
+
+        assertEquals(res.status, 429);
+        const json = await res.json();
+        assertEquals(json.error, "Too Many Requests");
+        assert(isRateLimitedCalled);
+        assert(!checkRateLimitCalled); // didn't reach failure branch
+      } finally {
+        rateLimitWrapper.isRateLimited = () => Promise.resolve(false);
+        rateLimitWrapper.checkRateLimit = () => Promise.resolve(true);
+      }
+    },
+  );
+
+  await t.step(
+    "POST /api/join normalizes slug case-insensitively while preserving hyphens",
+    async () => {
+      const originalSql = sqlWrapper.sql;
+      sqlWrapper.sql = ((strings: any, ...values: any[]) => {
+        const query = Array.isArray(strings)
+          ? strings.join("?")
+          : String(strings);
+        if (query.includes("SELECT * FROM event_passes")) {
+          assert(values.includes("deno-lab-workshop"));
+          return Promise.resolve([{
+            id: "event-uuid-2",
+            slug: "deno-lab-workshop",
+            pin_code: "111-222",
+            name: "Deno Workshop 2",
+            max_seats: 50,
+            seats_claimed: 0,
+            lifespan_hours: 3,
+            app_id: null,
+          }]);
+        }
+        if (query.includes("UPDATE event_passes")) {
+          return Promise.resolve([{
+            id: "event-uuid-2",
+            slug: "deno-lab-workshop",
+            pin_code: "111-222",
+            name: "Deno Workshop 2",
+            max_seats: 50,
+            seats_claimed: 1,
+            lifespan_hours: 3,
+            app_id: null,
+          }]);
+        }
+        return Promise.resolve([]);
+      }) as any;
+
+      const valkeySetexStub = stub(
+        valkey,
+        "setex",
+        () => Promise.resolve("OK" as any),
+      );
+
+      try {
+        const res = await app.request("/api/join", {
+          method: "POST",
+          headers: {
+            "Content-Type": "application/json",
+            "X-Forwarded-For": "192.168.1.1",
+          },
+          body: JSON.stringify({ code: " Deno-Lab-Workshop " }),
+        });
+
+        assertEquals(res.status, 200);
+        const json = await res.json();
+        assert(json.success === true);
+        assertEquals(json.username, "guest_deno-lab-workshop_1");
+      } finally {
+        sqlWrapper.sql = originalSql;
+        valkeySetexStub.restore();
+      }
+    },
+  );
+
   await t.step(
     "GET /join/:slug?format=env returns CLI export string",
     async () => {

ui/components/LoginPage.tsx

@@ -115,7 +115,9 @@ export const LoginPage = () => {
         </details>
 
         <div class="links">
-          Don't have an account? <a href="/register">Register with Invite</a>
+          Don't have an account? <a href="/register">Register with Invite</a> |
+          {" "}
+          <a href="/join">Join with PIN</a>
         </div>
       </div>
 

ui/components/RegisterPage.tsx

@@ -116,7 +116,8 @@ export const RegisterPage = (
           <div id="statusMessage"></div>
 
           <div class="links">
-            Already registered? <a href="/login">Sign in</a>
+            Already registered? <a href="/login">Sign in</a> |{" "}
+            <a href="/join">Join with PIN</a>
           </div>
         </div>