Allow message retries for "pending" status, refactor message context handling, remove workspace import/export routes, and add SQLite-backed rate limiting.

src/middleware/rateLimit.js

@@ -8,7 +8,7 @@ function pruneBucket(bucket, windowMs, now) {
     }
 }
 
-export function createRateLimiter({windowMs, max, keyGenerator, message, cleanupIntervalMs = 60 * 1000}) {
+export function createRateLimiter({windowMs, max, keyGenerator, message, cleanupIntervalMs = 60 * 1000, store = null}) {
     const hits = new Map();
     let cleanupTimer = null;
 
@@ -22,7 +22,7 @@ export function createRateLimiter({windowMs, max, keyGenerator, message, cleanup
         }
     };
 
-    if (cleanupIntervalMs > 0) {
+    if (!store && cleanupIntervalMs > 0) {
         cleanupTimer = setInterval(cleanup, cleanupIntervalMs);
         // Der Aufräumtimer allein soll den Node-Prozess beim Herunterfahren nicht offen halten.
         cleanupTimer.unref();
@@ -35,6 +35,10 @@ export function createRateLimiter({windowMs, max, keyGenerator, message, cleanup
         }
 
         const now = Date.now();
+        if (store) {
+            if (!store.consume(key, now, windowMs, max)) return res.status(429).json({error: message});
+            return next();
+        }
         const bucket = hits.get(key) || [];
         pruneBucket(bucket, windowMs, now);
         if (!bucket.length) {
@@ -59,3 +63,24 @@ export function createRateLimiter({windowMs, max, keyGenerator, message, cleanup
 
     return limiter;
 }
+
+// SQLite is already shared by all application instances and serializes this
+// short transaction, so the check-and-increment remains atomic across workers.
+export function createSqliteRateLimitStore(db) {
+    db.exec(`CREATE TABLE IF NOT EXISTS rate_limit_hits (
+        bucket_key TEXT NOT NULL,
+        hit_at INTEGER NOT NULL
+    );
+    CREATE INDEX IF NOT EXISTS rate_limit_hits_expiry ON rate_limit_hits(hit_at);`);
+    db.pragma("busy_timeout = 5000");
+    const prune = db.prepare("DELETE FROM rate_limit_hits WHERE bucket_key = ? AND hit_at <= ?");
+    const count = db.prepare("SELECT COUNT(*) AS count FROM rate_limit_hits WHERE bucket_key = ?");
+    const insert = db.prepare("INSERT INTO rate_limit_hits (bucket_key, hit_at) VALUES (?, ?)");
+    const consume = db.transaction((key, now, windowMs, max) => {
+        prune.run(key, now - windowMs);
+        if (count.get(key).count >= max) return false;
+        insert.run(key, now);
+        return true;
+    });
+    return {consume};
+}

src/middleware/rateLimiters.js

@@ -3,12 +3,13 @@
  */
 import {createRateLimiter} from "./rateLimit.js";
 
-export function createAuthRateLimiters(config) {
+export function createAuthRateLimiters(config, store = null) {
     return [
         createRateLimiter({
             windowMs: config.authRateLimitWindowMs,
             max: config.authRateLimitMaxPerIp,
             cleanupIntervalMs: config.rateLimitCleanupIntervalMs,
+            store,
             keyGenerator: (req) => `auth:ip:${req.ip}`,
             message: "Too many authentication attempts from this IP. Please try again later."
         }),
@@ -16,6 +17,7 @@ export function createAuthRateLimiters(config) {
             windowMs: config.authRateLimitWindowMs,
             max: config.authRateLimitMaxPerAccount,
             cleanupIntervalMs: config.rateLimitCleanupIntervalMs,
+            store,
             keyGenerator: (req) => {
                 const username = String(req.body?.username || "").trim().toLowerCase();
                 return username ? `auth:user:${username}` : null;
@@ -25,12 +27,13 @@ export function createAuthRateLimiters(config) {
     ];
 }
 
-export function createChatRateLimiters(config) {
+export function createChatRateLimiters(config, store = null) {
     return [
         createRateLimiter({
             windowMs: config.chatRateLimitWindowMs,
             max: config.chatRateLimitMaxPerIp,
             cleanupIntervalMs: config.rateLimitCleanupIntervalMs,
+            store,
             keyGenerator: (req) => `chat:ip:${req.ip}`,
             message: "Too many chat requests from this IP. Please slow down."
         }),
@@ -38,6 +41,7 @@ export function createChatRateLimiters(config) {
             windowMs: config.chatRateLimitWindowMs,
             max: config.chatRateLimitMaxPerAccount,
             cleanupIntervalMs: config.rateLimitCleanupIntervalMs,
+            store,
             keyGenerator: (req) => req.session.user ? `chat:user:${req.session.user}` : null,
             message: "Too many chat requests for this account. Please slow down."
         })