diff --git a/changelog.d/fixes/8728-model-catalog-swr.md b/changelog.d/fixes/8728-model-catalog-swr.md
new file mode 100644
index 0000000000..9272b3f0b7
--- /dev/null
+++ b/changelog.d/fixes/8728-model-catalog-swr.md
@@ -0,0 +1 @@
+- **fix(api):** make `/v1/models` stale refresh response-safe and generation-safe, with narrow synced-model invalidation ([#8728](https://github.com/diegosouzapw/OmniRoute/pull/8728)). Related to #8697.
diff --git a/src/app/api/v1/models/catalog.ts b/src/app/api/v1/models/catalog.ts
index 8dc554f056..8733341495 100644
--- a/src/app/api/v1/models/catalog.ts
+++ b/src/app/api/v1/models/catalog.ts
@@ -109,18 +109,25 @@ export { getCustomVisionCapabilityFields };
 // lives in ./catalogCache. Re-exported here because the existing tests import the
 // hooks from this module, and CATALOG_STALE_WHILE_REVALIDATE_MS is part of the
 // documented behavior of this endpoint.
-import { CATALOG_CACHE_TTL_MS_DEFAULT, resolveCachedCatalogResponse } from "./catalogCache";
+import {
+  CATALOG_CACHE_TTL_MS_DEFAULT,
+  resolveCachedCatalogResponse,
+  type CatalogCachePolicy,
+} from "./catalogCache";
 
 export {
   CATALOG_STALE_WHILE_REVALIDATE_MS,
+  getCatalogStaleWhileRevalidateMs,
   __resetCatalogBuilderRunsForTest,
   __getCatalogBuilderRunsForTest,
   __expireCatalogCacheForTest,
   __setCatalogCacheEntryForTest,
   __flushCatalogBackgroundRefreshForTest,
   __forceCatalogInFlightRejectionForTest,
+  __setCatalogStaleWhileRevalidateAccessorForTest,
+  __setCatalogStaleWhileRevalidateMsForTest,
 } from "./catalogCache";
-export type { CachedCatalog } from "./catalogCache";
+export type { CachedCatalog, CatalogCachePolicy } from "./catalogCache";
 
 /**
  * Build unified OpenAI-compatible model catalog response.
@@ -128,7 +135,8 @@ export type { CachedCatalog } from "./catalogCache";
  */
 export async function getUnifiedModelsResponse(
   request: Request,
-  corsHeaders: Record<string, string> = {}
+  corsHeaders: Record<string, string> = {},
+  cachePolicy: CatalogCachePolicy = {}
 ) {
   const diagnosticHeaders = getCatalogDiagnosticsHeaders({ request });
 
@@ -160,7 +168,8 @@ export async function getUnifiedModelsResponse(
     return await resolveCachedCatalogResponse(
       request,
       { corsHeaders, diagnosticHeaders },
-      buildCatalogPayload
+      buildCatalogPayload,
+      cachePolicy
     );
   } catch (err) {
     // Hard rule #12: never put a raw err.message/err.stack in a response body.
diff --git a/src/app/api/v1/models/catalogCache.ts b/src/app/api/v1/models/catalogCache.ts
index 1cff2fa64f..da08307bd5 100644
--- a/src/app/api/v1/models/catalogCache.ts
+++ b/src/app/api/v1/models/catalogCache.ts
@@ -5,15 +5,16 @@
  * builder walks 8 registries and hits SQLite for connections, combos, custom
  * models and aliases; under Next.js's single-threaded App Router request
  * handling, N concurrent calls execute back-to-back and the Nth completes at
- * N × single-request latency. So identical concurrent requests are coalesced
- * onto one in-flight promise and the serialized body is memoized for a short
- * window.
+ * N × single-request latency. Identical concurrent requests are therefore
+ * coalesced onto one in-flight promise and successful serialized bodies are
+ * memoized for a short fresh window.
  *
  * Auth rejection is NOT handled here and must stay in the caller: it depends on
  * live per-request state (dashboard cookie, API key) and must never be cached.
  */
 import { getModelCatalogCacheVersion } from "@/lib/db/readCache";
 import { extractApiKey } from "@/sse/services/auth";
+import { after } from "next/server";
 
 import { isCodexModelCatalogClient } from "./catalogRequest";
 
@@ -24,7 +25,7 @@ export type CachedCatalog = {
   expiresAt: number;
 };
 
-/** Payload shape returned by the builder the caller injects. */
+/** Payload shape returned by the shared builder primitive the caller injects. */
 export type CatalogPayload = {
   body: string;
   headers: Record<string, string>;
@@ -32,54 +33,65 @@ export type CatalogPayload = {
   cacheTTL: number;
 };
 
+export type CatalogRefreshTask = () => Promise<void>;
+export type CatalogRefreshScheduler = (task: CatalogRefreshTask) => void;
+
 /**
- * A client with a short discovery timeout (Claude Code allows 3 s) must never
- * wait on a full rebuild. Once a cached 200 expires it is still served
- * immediately for up to this long while a background refresh repopulates it.
- * Bounded so a refresh that keeps failing cannot pin an old catalog forever —
- * past this window callers fall back to waiting, same as a cold cache.
+ * Per-call cache policy. Request-context routes inject Next.js `after()` as the
+ * scheduler; unit tests and direct non-framework callers can inject a deterministic
+ * scheduler without making the cache branch on runner-specific environment variables.
  */
-export const CATALOG_STALE_WHILE_REVALIDATE_MS = 30_000;
+export type CatalogCachePolicy = {
+  getStaleWhileRevalidateMs?: () => number;
+  scheduleBackgroundRefresh?: CatalogRefreshScheduler;
+};
+
+/**
+ * Production stale-while-revalidate window.
+ *
+ * A successful snapshot remains eligible indefinitely after the 60-second fresh TTL.
+ * TTL expiry requests return that last success and schedule one refresh. Database state
+ * changes are different: the version signal below hard-invalidates every snapshot and
+ * makes the next request await a current-generation build.
+ */
+export const CATALOG_STALE_WHILE_REVALIDATE_MS = Number.POSITIVE_INFINITY;
 
 /**
  * Fallback memoization window; overridden by `settings.cache.modelCatalogCacheTtlMs`.
  *
- * This does NOT govern post-write freshness — `invalidateDbCache()` bumps
- * `modelCatalogCacheVersion` on every settings/connections/combos/pricing write and
- * `dropCatalogCacheIfStateChanged()` drops the whole cache the moment it moves, so a
- * write is reflected on the very next read regardless of this value. What it governs is
- * the "nothing was written" case, where replaying a body built seconds ago is precisely
- * the point of the cache.
- *
- * It was 1500 ms, which was shorter than a single build: measured 2026-07-28 on the
- * production VPS, the builder takes ~49 s for a 1.3 MB / 2645-model catalog. Any two
- * requests more than 1.5 s apart therefore both missed the fresh window, and the second
- * fell into stale-while-revalidate — which rebuilds via `setTimeout(…, 0)` and, because
- * the builder is overwhelmingly synchronous under the single-threaded App Router, pins
- * the event loop so even the "served immediately" stale body only reaches the client
- * once the rebuild finishes. Net effect: ~50 s on essentially every call.
- *
- * Held at 60 s to match the ceiling the settings schema already allows for the override
- * (`settingsSchemas.ts`, `.max(60000)`), so the default can never exceed what an
- * operator is permitted to configure.
+ * This is only the fresh window. Ordinary expiry serves the last successful snapshot
+ * while refreshing. `modelCatalogCacheVersion` changes bypass stale serving entirely.
  */
 export const CATALOG_CACHE_TTL_MS_DEFAULT = 60_000;
 
+type CatalogInFlight = {
+  generation: number;
+  promise: Promise<CatalogPayload>;
+};
+
 const catalogCache = new Map<string, CachedCatalog>();
+const catalogInFlight = new Map<string, CatalogInFlight>();
 
-/**
- * An in-flight build is bound to the catalog-state generation it started from
- * (`getModelCatalogCacheVersion()` at launch). After a write invalidates the
- * catalog, the generation moves on: a stale in-flight build must neither be
- * joined by new requests nor repopulate the now-current cache when it finishes.
- * It still resolves to its own original caller (that request legitimately waits
- * on it), just without being persisted.
- */
-type InFlightBuild = { generation: number; promise: Promise<CachedCatalog> };
-const catalogInFlight = new Map<string, InFlightBuild>();
-
+let catalogGeneration = 0;
+let lastSeenCatalogCacheVersion = getModelCatalogCacheVersion();
+let staleWhileRevalidateMsAccessor = () => CATALOG_STALE_WHILE_REVALIDATE_MS;
 let _catalogBuilderRuns = 0;
 
+function defaultBackgroundRefreshScheduler(task: CatalogRefreshTask): void {
+  // All production routes run in Next.js request context, including callers that transform the
+  // shared response. Direct test/startup callers have no request store and need a safe fallback.
+  try {
+    after(task);
+  } catch {
+    setImmediate(() => void task());
+  }
+}
+
+/** Current SWR policy value; production defaults to unbounded stale serving. */
+export function getCatalogStaleWhileRevalidateMs(): number {
+  return staleWhileRevalidateMsAccessor();
+}
+
 function buildCatalogCacheKey(request: Request): string {
   const url = new URL(request.url);
   const prefix = url.searchParams.get("prefix") || "";
@@ -89,32 +101,28 @@ function buildCatalogCacheKey(request: Request): string {
   return `${prefix}|${isCodex}|${apiKey}|${configuredOnly}`;
 }
 
-// Tracks the model-catalog cache version (src/lib/db/readCache.ts) as of the last
-// cache access. invalidateDbCache() bumps that version on every settings/connections/
-// combos/pricing write; when it moves on, every memoized entry here was built from
-// state that no longer holds, so drop them all rather than keying by version (which
-// would leak one Map entry per version forever instead of ever pruning old ones).
-let lastSeenCatalogCacheVersion = getModelCatalogCacheVersion();
-function dropCatalogCacheIfStateChanged(): void {
+/**
+ * Observe the DB-side invalidation signal.
+ *
+ * Every observed version transition is hard invalidation: snapshots are cleared,
+ * the local generation advances, and old work is detached. Completion guards also
+ * call this function, so a version change that occurs while a builder is running
+ * prevents that builder from writing even before another request arrives.
+ */
+function synchronizeCatalogGeneration(): void {
   const currentVersion = getModelCatalogCacheVersion();
   if (currentVersion === lastSeenCatalogCacheVersion) return;
+
   lastSeenCatalogCacheVersion = currentVersion;
+  catalogGeneration++;
   catalogCache.clear();
-  // Deliberately NOT clearing catalogInFlight: an in-flight build bound to the
-  // previous generation is left to finish for its original caller, but the
-  // generation check in the join path (below) keeps new requests from joining
-  // it, and the generation check in storePayload keeps it from repopulating
-  // the now-current cache. Clearing it here would just detach the entry while
-  // the build still ran — wasted work with no correctness gain.
+  catalogInFlight.clear();
 }
 
 // Header sources mix Title-Case keys (diagnostic/cors headers built by app code) with
-// lower-case ones (payload headers captured via the Fetch `Headers` iterator). A plain
-// object spread keeps both casings as distinct keys, and the `Response` constructor
-// then *appends* rather than overwrites them, producing comma-joined duplicates (e.g.
-// request-id echoing "foo, foo"). Merge through a real `Headers` so `.set()` overwrites
-// case-insensitively. Earlier sources are the base; the caller passes diagnostics last
-// so per-request fields reflect the current request, not whichever one filled the cache.
+// lower-case ones (payload headers captured via the Fetch `Headers` iterator). Merge
+// through a real Headers so the caller's per-request diagnostics overwrite cached values
+// case-insensitively.
 export function mergeCatalogHeaders(
   ...sources: Array<Record<string, string> | undefined>
 ): Headers {
@@ -128,81 +136,26 @@ export function mergeCatalogHeaders(
   return merged;
 }
 
-/**
- * Persist a freshly built payload — but only when the build still belongs to the
- * current catalog-state generation. A build that started before a write
- * invalidation (its `buildGeneration` is older than `getModelCatalogCacheVersion()`)
- * returns its entry to its original caller but must NOT repopulate the cache: the
- * payload reflects pre-write state and caching it would serve stale data.
- */
-function storePayload(
+function isSuccessfulPayload(payload: CatalogPayload): boolean {
+  return payload.status >= 200 && payload.status < 300;
+}
+
+function storeSuccessfulPayload(
   cacheKey: string,
   payload: CatalogPayload,
-  buildGeneration: number
-): CachedCatalog {
-  const entry: CachedCatalog = {
+  inFlight: CatalogInFlight
+): void {
+  synchronizeCatalogGeneration();
+  if (!isSuccessfulPayload(payload)) return;
+  if (inFlight.generation !== catalogGeneration) return;
+  if (catalogInFlight.get(cacheKey) !== inFlight) return;
+
+  catalogCache.set(cacheKey, {
     body: payload.body,
     headers: payload.headers,
     status: payload.status,
     expiresAt: Date.now() + payload.cacheTTL,
-  };
-  if (buildGeneration === getModelCatalogCacheVersion()) {
-    catalogCache.set(cacheKey, entry);
-  }
-  return entry;
-}
-
-/**
- * Kick off a background rebuild so an expired-but-stale-eligible entry can be
- * refreshed without the current request waiting on it. Reuses catalogInFlight —
- * no second coalescing mechanism — so a concurrent cold/stale request for the
- * same key joins this refresh instead of starting another.
- *
- * The builder runs one macrotask later so the stale response that triggered this
- * call is handed back before the builder's synchronous prologue runs; the whole
- * point of this path is that the caller does not pay for the rebuild.
- *
- * The tracked promise **rejects** on failure. catalogInFlight is shared with the
- * cold path: a caller whose entry aged past the stale window skips the stale
- * branch and awaits whatever promise it finds here, and resolving with the stale
- * entry would hand it a body it was no longer entitled to while disguising a
- * build failure as a 200. The rejection is pre-handled so this path can never
- * raise an unhandledRejection; a failed refresh simply never overwrites the entry.
- */
-function scheduleBackgroundRefresh(
-  cacheKey: string,
-  request: Request,
-  buildPayload: (request: Request) => Promise<CatalogPayload>
-): void {
-  if (catalogInFlight.has(cacheKey)) return; // a refresh for this key is already running
-
-  const generation = getModelCatalogCacheVersion();
-  const refreshPromise: Promise<CachedCatalog> = new Promise((resolve, reject) => {
-    setTimeout(() => {
-      runBuilder(buildPayload, request)
-        .then((payload) => resolve(storePayload(cacheKey, payload, generation)))
-        .catch((err) => {
-          console.error(
-            `[catalog] Background stale-while-revalidate refresh failed for key "${cacheKey}":`,
-            err
-          );
-          reject(err);
-        });
-    }, 0);
   });
-
-  // Nobody on the stale path awaits this, so pre-handle the rejection; a cold-path
-  // caller that joins it via catalogInFlight attaches its own handler and still
-  // observes the failure.
-  refreshPromise.catch(() => {});
-
-  catalogInFlight.set(cacheKey, { generation, promise: refreshPromise });
-  refreshPromise
-    .catch(() => {})
-    .finally(() => {
-      if (catalogInFlight.get(cacheKey)?.promise === refreshPromise)
-        catalogInFlight.delete(cacheKey);
-    });
 }
 
 function runBuilder(
@@ -210,23 +163,104 @@ function runBuilder(
   request: Request
 ): Promise<CatalogPayload> {
   _catalogBuilderRuns++;
-  return buildPayload(request);
+  try {
+    return Promise.resolve(buildPayload(request));
+  } catch (error) {
+    return Promise.reject(error);
+  }
+}
+
+function cleanInFlight(cacheKey: string, inFlight: CatalogInFlight): void {
+  if (catalogInFlight.get(cacheKey) === inFlight) {
+    catalogInFlight.delete(cacheKey);
+  }
+}
+
+function startSynchronousBuild(
+  cacheKey: string,
+  request: Request,
+  buildPayload: (request: Request) => Promise<CatalogPayload>
+): CatalogInFlight {
+  const generation = catalogGeneration;
+  let inFlight!: CatalogInFlight;
+  const promise = runBuilder(buildPayload, request).then((payload) => {
+    storeSuccessfulPayload(cacheKey, payload, inFlight);
+    return payload;
+  });
+  inFlight = { generation, promise };
+  catalogInFlight.set(cacheKey, inFlight);
+  inFlight.promise.then(
+    () => cleanInFlight(cacheKey, inFlight),
+    () => cleanInFlight(cacheKey, inFlight)
+  );
+  return inFlight;
+}
+
+function scheduleBackgroundRefresh(
+  cacheKey: string,
+  request: Request,
+  buildPayload: (request: Request) => Promise<CatalogPayload>,
+  schedule: CatalogRefreshScheduler
+): void {
+  if (catalogInFlight.has(cacheKey)) return;
+
+  let resolveRefresh!: (payload: CatalogPayload) => void;
+  let rejectRefresh!: (error: unknown) => void;
+  const inFlight: CatalogInFlight = {
+    generation: catalogGeneration,
+    promise: new Promise<CatalogPayload>((resolve, reject) => {
+      resolveRefresh = resolve;
+      rejectRefresh = reject;
+    }),
+  };
+
+  // Reserve the key before handing the task to the scheduler. Multiple stale reads in
+  // the same request turn therefore cannot enqueue duplicate refreshes.
+  catalogInFlight.set(cacheKey, inFlight);
+  void inFlight.promise.catch(() => {}); // background failures are always handled
+
+  const task: CatalogRefreshTask = async () => {
+    synchronizeCatalogGeneration();
+    if (inFlight.generation !== catalogGeneration || catalogInFlight.get(cacheKey) !== inFlight) {
+      // Hard invalidation or a deterministic test reset detached this scheduled task
+      // before it started. Resolve its private bookkeeping promise without rebuilding.
+      resolveRefresh({ body: "", headers: {}, status: 204, cacheTTL: 0 });
+      return;
+    }
+
+    try {
+      const payload = await runBuilder(buildPayload, request);
+      storeSuccessfulPayload(cacheKey, payload, inFlight);
+      resolveRefresh(payload);
+    } catch (error) {
+      console.error("[catalog] Background stale-while-revalidate refresh failed:", error);
+      rejectRefresh(error);
+    } finally {
+      cleanInFlight(cacheKey, inFlight);
+    }
+  };
+
+  try {
+    schedule(task);
+  } catch (error) {
+    cleanInFlight(cacheKey, inFlight);
+    rejectRefresh(error);
+    console.error("[catalog] Failed to schedule background refresh:", error);
+  }
 }
 
 /**
- * Resolve the cached catalog response for `request`, building it through
- * `buildPayload` when there is nothing fresh to serve.
- *
- * Returns `null` when the caller must build and handle errors itself — i.e. the
- * in-flight build rejected — so the error-response shape stays in the caller.
+ * Resolve the cached catalog response for `request`, building it through the shared
+ * `buildPayload` primitive when there is no current snapshot.
  */
 export async function resolveCachedCatalogResponse(
   request: Request,
   headerSources: { corsHeaders: Record<string, string>; diagnosticHeaders: Record<string, string> },
-  buildPayload: (request: Request) => Promise<CatalogPayload>
+  buildPayload: (request: Request) => Promise<CatalogPayload>,
+  policy: CatalogCachePolicy = {}
 ): Promise<Response> {
   const { corsHeaders, diagnosticHeaders } = headerSources;
-  dropCatalogCacheIfStateChanged();
+  synchronizeCatalogGeneration();
 
   const cacheKey = buildCatalogCacheKey(request);
   const now = Date.now();
@@ -239,41 +273,32 @@ export async function resolveCachedCatalogResponse(
     });
   }
 
-  // Stale-while-revalidate: an expired entry is still served immediately as long as
-  // (a) it was a successful build — a cached error replayed as "stale" would mask an
-  // intermittent failure behind a fake success forever — and (b) it is within the
-  // staleness window, so a refresh that keeps failing eventually falls through to the
-  // cold-path wait instead of pinning ancient data.
+  const staleWhileRevalidateMs =
+    policy.getStaleWhileRevalidateMs?.() ?? getCatalogStaleWhileRevalidateMs();
   if (
     cached &&
-    cached.status === 200 &&
-    now - cached.expiresAt <= CATALOG_STALE_WHILE_REVALIDATE_MS
+    cached.status >= 200 &&
+    cached.status < 300 &&
+    now - cached.expiresAt <= staleWhileRevalidateMs
   ) {
-    scheduleBackgroundRefresh(cacheKey, request, buildPayload);
+    scheduleBackgroundRefresh(
+      cacheKey,
+      request,
+      buildPayload,
+      policy.scheduleBackgroundRefresh ?? defaultBackgroundRefreshScheduler
+    );
     return new Response(cached.body, {
       status: cached.status,
       headers: mergeCatalogHeaders(corsHeaders, cached.headers, diagnosticHeaders),
     });
   }
 
-  const currentGeneration = getModelCatalogCacheVersion();
-  let inflight = catalogInFlight.get(cacheKey);
-  // Only join an in-flight build from the CURRENT generation. A build bound to an
-  // older (pre-write) generation reflects stale state, so a new request starts a
-  // fresh build instead of joining it.
-  if (!inflight || inflight.generation !== currentGeneration) {
-    const generation = currentGeneration;
-    const promise = runBuilder(buildPayload, request).then((payload) =>
-      storePayload(cacheKey, payload, generation)
-    );
-    inflight = { generation, promise };
-    catalogInFlight.set(cacheKey, inflight);
-    promise.finally(() => {
-      if (catalogInFlight.get(cacheKey)?.promise === promise) catalogInFlight.delete(cacheKey);
-    });
+  let inFlight = catalogInFlight.get(cacheKey);
+  if (!inFlight) {
+    inFlight = startSynchronousBuild(cacheKey, request, buildPayload);
   }
 
-  const payload = await inflight.promise;
+  const payload = await inFlight.promise;
   return new Response(payload.body, {
     status: payload.status,
     headers: mergeCatalogHeaders(corsHeaders, payload.headers, diagnosticHeaders),
@@ -281,14 +306,26 @@ export async function resolveCachedCatalogResponse(
 }
 
 // ── Test hooks ───────────────────────────────────────────────────────────────
-// Not part of the public API; do not read from app code.
+// Not part of the public application API.
 
-/** Resets the builder counter and every cached/in-flight entry. */
+/** Deterministically resets counters, policy, snapshots, generations, and old work. */
 export function __resetCatalogBuilderRunsForTest(): void {
   _catalogBuilderRuns = 0;
+  catalogGeneration++;
   catalogCache.clear();
   catalogInFlight.clear();
   lastSeenCatalogCacheVersion = getModelCatalogCacheVersion();
+  staleWhileRevalidateMsAccessor = () => CATALOG_STALE_WHILE_REVALIDATE_MS;
+}
+
+/** Injects the SWR policy accessor without environment-dependent behavior. */
+export function __setCatalogStaleWhileRevalidateAccessorForTest(accessor: () => number): void {
+  staleWhileRevalidateMsAccessor = accessor;
+}
+
+/** Backward-compatible scalar policy hook retained for focused tests. */
+export function __setCatalogStaleWhileRevalidateMsForTest(ms: number): void {
+  staleWhileRevalidateMsAccessor = () => ms;
 }
 
 /** Counts full builder executions — proves concurrent requests share one run (#6408). */
@@ -296,11 +333,7 @@ export function __getCatalogBuilderRunsForTest(): number {
   return _catalogBuilderRuns;
 }
 
-/**
- * Marks every cached entry as expired `msAgo` milliseconds ago instead of sleeping
- * out the real TTL. Pass more than CATALOG_STALE_WHILE_REVALIDATE_MS to simulate an
- * entry that has aged past the stale-serving window.
- */
+/** Marks every successful snapshot expired without sleeping out the real TTL. */
 export function __expireCatalogCacheForTest(msAgo = 1): void {
   const expiresAt = Date.now() - msAgo;
   for (const [key, entry] of catalogCache.entries()) {
@@ -308,38 +341,22 @@ export function __expireCatalogCacheForTest(msAgo = 1): void {
   }
 }
 
-/**
- * Seeds the entry a given request would read, for status/staleness combinations the
- * intentionally exception-resistant builder cannot be made to produce (e.g. a cached
- * non-200). Takes the Request so the cache-key format stays private to this module.
- */
+/** Seeds a request-keyed snapshot for status/staleness compatibility tests. */
 export function __setCatalogCacheEntryForTest(request: Request, entry: CachedCatalog): void {
   catalogCache.set(buildCatalogCacheKey(request), entry);
 }
 
-/** Awaits any background refresh in flight, instead of guessing at a real-time sleep. */
+/** Awaits any currently running or scheduled refresh without real-time sleeps. */
 export async function __flushCatalogBackgroundRefreshForTest(): Promise<void> {
-  await Promise.all([...catalogInFlight.values()].map((entry) => entry.promise.catch(() => {})));
+  await Promise.all([...catalogInFlight.values()].map(({ promise }) => promise.catch(() => {})));
 }
 
-/**
- * Injects a synthetic in-flight rejection so the caller's catch branch (sanitized
- * error body) can be exercised deterministically — the builder core try/catches every
- * registry and DB read individually, so it is not a practical error-injection point.
- *
- * Deliberately does not self-clean the way production entries do: this promise is
- * already rejected at creation, so a cleanup callback would delete the map entry
- * within a microtask or two — before the caller's several-await auth check finishes —
- * silently swapping in a fresh cold build instead of the intended failure. The next
- * __resetCatalogBuilderRunsForTest() clears it.
- */
+/** Injects a handled in-flight rejection for the catalog error-shape regression test. */
 export function __forceCatalogInFlightRejectionForTest(request: Request, error: unknown): void {
-  const rejected: Promise<CachedCatalog> = Promise.reject(error);
-  rejected.catch(() => {}); // mark as handled — avoids an unhandledRejection warning
-  // Bind to the current generation so the cold path still joins it (a stale
-  // generation would be skipped as pre-write state and never awaited).
+  const promise: Promise<CatalogPayload> = Promise.reject(error);
+  void promise.catch(() => {});
   catalogInFlight.set(buildCatalogCacheKey(request), {
-    generation: getModelCatalogCacheVersion(),
-    promise: rejected,
+    generation: catalogGeneration,
+    promise,
   });
 }
diff --git a/src/app/api/v1/models/route.ts b/src/app/api/v1/models/route.ts
index f884388ae8..da37ca65e8 100644
--- a/src/app/api/v1/models/route.ts
+++ b/src/app/api/v1/models/route.ts
@@ -1,3 +1,5 @@
+import { after } from "next/server";
+
 import { getUnifiedModelsResponse } from "./catalog";
 
 /**
@@ -31,5 +33,11 @@ export async function HEAD() {
  * GET /v1/models - OpenAI compatible models list
  */
 export async function GET(request: Request) {
-  return getUnifiedModelsResponse(request);
+  return getUnifiedModelsResponse(
+    request,
+    {},
+    {
+      scheduleBackgroundRefresh: (task) => after(task),
+    }
+  );
 }
diff --git a/src/lib/catalog/openrouterCatalog.ts b/src/lib/catalog/openrouterCatalog.ts
index cb60ec0f96..47a0891eb0 100644
--- a/src/lib/catalog/openrouterCatalog.ts
+++ b/src/lib/catalog/openrouterCatalog.ts
@@ -9,6 +9,7 @@
 
 import fs from "fs";
 import path from "path";
+import { invalidateModelCatalogCache } from "@/lib/db/readCache";
 
 const OPENROUTER_API_URL = "https://openrouter.ai/api/v1/models";
 const DEFAULT_TTL_MS = 24 * 60 * 60 * 1000; // 24 hours
@@ -169,6 +170,7 @@ export async function refreshOpenRouterCatalog(): Promise<{
   try {
     const data = await fetchFromAPI();
     writeCache(data);
+    invalidateModelCatalogCache();
     return { data, ok: true };
   } catch (err) {
     const error = err instanceof Error ? err.message : String(err);
diff --git a/src/lib/db/apiKeyGroups.ts b/src/lib/db/apiKeyGroups.ts
index d14d69974b..22a85ac3ef 100644
--- a/src/lib/db/apiKeyGroups.ts
+++ b/src/lib/db/apiKeyGroups.ts
@@ -9,6 +9,7 @@
 
 import { getDbInstance } from "@/lib/db/core";
 import { randomUUID } from "crypto";
+import { invalidateModelCatalogCache } from "./readCache";
 
 // ── Types ────────────────────────────────────────────────────────────────
 
@@ -71,7 +72,7 @@ export function createKeyGroup(name: string, description = ""): KeyGroup {
   const now = new Date().toISOString();
 
   db.prepare(
-    "INSERT INTO key_groups (id, name, description, created_at, updated_at) VALUES (?, ?, ?, ?, ?)"
+    "INSERT INTO key_groups (id, name, description, created_at, updated_at) VALUES (?, ?, ?, ?, ?)",
   ).run(id, name, description, now, now);
 
   return getKeyGroup(id)!;
@@ -79,7 +80,7 @@ export function createKeyGroup(name: string, description = ""): KeyGroup {
 
 export function updateKeyGroup(
   id: string,
-  updates: { name?: string; description?: string; isActive?: boolean }
+  updates: { name?: string; description?: string; isActive?: boolean },
 ): KeyGroup | undefined {
   const existing = getKeyGroup(id);
   if (!existing) return undefined;
@@ -102,17 +103,27 @@ export function updateKeyGroup(
   }
 
   if (sets.length === 0) return existing;
+  const catalogInvalidationNeeded =
+    updates.isActive !== undefined && updates.isActive !== existing.isActive;
+
   sets.push("updated_at = datetime('now')");
 
-  db.prepare(`UPDATE key_groups SET ${sets.join(", ")} WHERE id = @id`).run(params);
-  return getKeyGroup(id);
+  const result = db.prepare(`UPDATE key_groups SET ${sets.join(", ")} WHERE id = @id`).run(params);
+  if (catalogInvalidationNeeded && result.changes > 0) {
+    invalidateModelCatalogCache();
+  }
+  return result.changes > 0 ? getKeyGroup(id) : existing;
 }
 
 export function deleteKeyGroup(id: string): boolean {
   const db = getDbInstance() as any;
   // CASCADE deletes permissions and members
   const result = db.prepare("DELETE FROM key_groups WHERE id = ?").run(id);
-  return result.changes > 0;
+  if (result.changes > 0) {
+    invalidateModelCatalogCache();
+    return true;
+  }
+  return false;
 }
 
 // ── Group Permissions ────────────────────────────────────────────────────
@@ -121,7 +132,7 @@ export function getGroupPermissions(groupId: string): GroupModelPermission[] {
   const db = getDbInstance() as any;
   const rows = db
     .prepare(
-      "SELECT * FROM group_model_permissions WHERE group_id = ? ORDER BY access_type ASC, model_pattern ASC"
+      "SELECT * FROM group_model_permissions WHERE group_id = ? ORDER BY access_type ASC, model_pattern ASC",
     )
     .all(groupId) as any[];
   return rows.map(rowToPermission);
@@ -131,15 +142,21 @@ export function addGroupPermission(
   groupId: string,
   modelPattern: string,
   accessType: "allow" | "deny",
-  provider?: string
+  provider?: string,
 ): GroupModelPermission {
   const db = getDbInstance() as any;
   const id = randomUUID();
   const now = new Date().toISOString();
 
-  db.prepare(
-    "INSERT INTO group_model_permissions (id, group_id, model_pattern, provider, access_type, created_at) VALUES (?, ?, ?, ?, ?, ?)"
-  ).run(id, groupId, modelPattern, provider || null, accessType, now);
+  const result = db
+    .prepare(
+      "INSERT INTO group_model_permissions (id, group_id, model_pattern, provider, access_type, created_at) VALUES (?, ?, ?, ?, ?, ?)",
+    )
+    .run(id, groupId, modelPattern, provider || null, accessType, now);
+
+  if (result.changes > 0) {
+    invalidateModelCatalogCache();
+  }
 
   return getGroupPermissions(groupId).find((p) => p.id === id)!;
 }
@@ -147,12 +164,18 @@ export function addGroupPermission(
 export function removeGroupPermission(permissionId: string): boolean {
   const db = getDbInstance() as any;
   const result = db.prepare("DELETE FROM group_model_permissions WHERE id = ?").run(permissionId);
+  if (result.changes > 0) {
+    invalidateModelCatalogCache();
+  }
   return result.changes > 0;
 }
 
 export function clearGroupPermissions(groupId: string): void {
   const db = getDbInstance() as any;
-  db.prepare("DELETE FROM group_model_permissions WHERE group_id = ?").run(groupId);
+  const result = db.prepare("DELETE FROM group_model_permissions WHERE group_id = ?").run(groupId);
+  if (result.changes > 0) {
+    invalidateModelCatalogCache();
+  }
 }
 
 // ── Key Group Members ────────────────────────────────────────────────────
@@ -174,7 +197,7 @@ export function getKeyGroupsForApiKey(keyId: string): KeyGroup[] {
     INNER JOIN key_group_members m ON g.id = m.group_id
     WHERE m.key_id = ? AND g.is_active = 1
     ORDER BY g.name ASC
-  `
+  `,
     )
     .all(keyId) as any[];
   return rows.map(rowToGroup);
@@ -183,10 +206,12 @@ export function getKeyGroupsForApiKey(keyId: string): KeyGroup[] {
 export function addKeyToGroup(keyId: string, groupId: string): boolean {
   const db = getDbInstance() as any;
   try {
-    db.prepare("INSERT OR IGNORE INTO key_group_members (key_id, group_id) VALUES (?, ?)").run(
-      keyId,
-      groupId
-    );
+    const result = db
+      .prepare("INSERT OR IGNORE INTO key_group_members (key_id, group_id) VALUES (?, ?)")
+      .run(keyId, groupId);
+    if (result.changes > 0) {
+      invalidateModelCatalogCache();
+    }
     return true;
   } catch {
     return false;
@@ -198,6 +223,9 @@ export function removeKeyFromGroup(keyId: string, groupId: string): boolean {
   const result = db
     .prepare("DELETE FROM key_group_members WHERE key_id = ? AND group_id = ?")
     .run(keyId, groupId);
+  if (result.changes > 0) {
+    invalidateModelCatalogCache();
+  }
   return result.changes > 0;
 }
 
@@ -224,7 +252,7 @@ export interface ModelAccessCheck {
 export function checkKeyModelAccess(
   keyId: string,
   model: string,
-  provider?: string
+  provider?: string,
 ): ModelAccessCheck {
   const groups = getKeyGroupsForApiKey(keyId);
   if (groups.length === 0) {
@@ -242,7 +270,7 @@ export function checkKeyModelAccess(
     SELECT * FROM group_model_permissions
     WHERE group_id IN (${placeholders})
     ORDER BY access_type ASC
-  `
+  `,
     )
     .all(...groupIds) as any[];
 
@@ -253,7 +281,7 @@ export function checkKeyModelAccess(
     (p) =>
       p.accessType === "deny" &&
       matchesModelPattern(p.modelPattern, model) &&
-      (!p.provider || p.provider === provider)
+      (!p.provider || p.provider === provider),
   );
 
   if (denyRules.length > 0) {
@@ -265,7 +293,7 @@ export function checkKeyModelAccess(
     (p) =>
       p.accessType === "allow" &&
       matchesModelPattern(p.modelPattern, model) &&
-      (!p.provider || p.provider === provider)
+      (!p.provider || p.provider === provider),
   );
 
   if (allowRules.length > 0) {
diff --git a/src/lib/db/apiKeys.ts b/src/lib/db/apiKeys.ts
index 0b43e699a9..2cb2cce347 100644
--- a/src/lib/db/apiKeys.ts
+++ b/src/lib/db/apiKeys.ts
@@ -48,6 +48,13 @@ import {
   parseStreamDefaultMode,
   parseChaosModeEnabled,
 } from "./apiKeys/rowParsers";
+import {
+  clearModelPermissionCache,
+  getCachedModelPermission,
+  setCachedModelPermission,
+  evictModelPermissionCache,
+} from "./apiKeys/modelPermissionCache";
+import { getModelCatalogCacheVersion, invalidateModelCatalogCache } from "./readCache";
 import type { AccessSchedule, RateLimitRule } from "./apiKeys/types";
 
 // ──────────────── Performance Optimizations ────────────────
@@ -62,7 +69,6 @@ interface CacheEntry<TValue> {
   value: TValue;
 }
 
-// Re-exported for the historical public surface (moved to ./apiKeys/types).
 export type { AccessSchedule, RateLimitRule } from "./apiKeys/types";
 
 interface ApiKeyMetadata {
@@ -82,9 +88,7 @@ interface ApiKeyMetadata {
   maxRequestsPerMinute: number | null;
   throttleDelayMs: number | null;
   rateLimits: RateLimitRule[] | null;
-  // T08: Per-key max concurrent sticky sessions (0 = unlimited)
   maxSessions: number;
-  // Phase 3 lifecycle/policy fields
   revokedAt: string | null;
   expiresAt: string | null;
   ipAllowlist: string[];
@@ -198,12 +202,6 @@ const CACHE_TTL = 60 * 1000; // 1 minute TTL
 const LAST_USED_UPDATE_TTL = 5 * 60 * 1000;
 const MAX_CACHE_SIZE = 1000;
 
-// Wildcard scope matching is now handled by `matchesWildcardPattern`
-// (deterministic, no RegExp from dynamic strings).
-
-// Cache for model permission checks
-const _modelPermissionCache = new Map<string, { allowed: boolean; timestamp: number }>();
-
 // Prepared statements cache
 let _stmtGetAllKeys: ApiKeysStatements["getAllKeys"] | null = null;
 let _stmtGetKeyById: ApiKeysStatements["getKeyById"] | null = null;
@@ -218,7 +216,7 @@ let _stmtDeleteKey: ApiKeysStatements["deleteKey"] | null = null;
 function invalidateCaches() {
   _keyValidationCache.clear();
   _keyMetadataCache.clear();
-  _modelPermissionCache.clear();
+  clearModelPermissionCache();
   _lastUsedUpdateCache.clear();
 }
 
@@ -278,12 +276,8 @@ function markApiKeyUsed(db: ApiKeysDbLike, id: unknown, now: number): void {
   _lastUsedUpdateCache.set(id, now);
 }
 
-/**
- * LRU eviction for cache
- */
 function evictIfNeeded<TKey, TValue>(cache: Map<TKey, TValue>) {
   if (cache.size > MAX_CACHE_SIZE) {
-    // Remove oldest 20% of entries
     const entriesToRemove = Math.floor(MAX_CACHE_SIZE * 0.2);
     let i = 0;
     for (const key of cache.keys()) {
@@ -315,7 +309,7 @@ async function getModelPermissionCandidates(modelId: string): Promise<string[]>
         providerOrAlias,
         providerScopedModel,
         resolveProviderId,
-        getProviderAlias
+        getProviderAlias,
       );
     }
     return Array.from(candidates);
@@ -333,7 +327,7 @@ async function getModelPermissionCandidates(modelId: string): Promise<string[]>
 }
 
 async function getPublishedModelLookupTarget(
-  modelId: string
+  modelId: string,
 ): Promise<{ providerId: string; modelId: string } | null> {
   const cleanModelId = stripExtendedContextSuffix(modelId.trim());
   if (!cleanModelId) return null;
@@ -362,14 +356,13 @@ async function getPublishedModelLookupTarget(
 function ensureApiKeyColumn(
   db: ApiKeysDbLike,
   columnNames: Set<string>,
-  column: (typeof API_KEY_COLUMN_FALLBACKS)[number]
+  column: (typeof API_KEY_COLUMN_FALLBACKS)[number],
 ): void {
   if (columnNames.has(column.name)) return;
   db.exec(`ALTER TABLE api_keys ADD COLUMN ${column.definition}`);
   console.log(`[DB] Added api_keys.${column.name} column`);
 }
 
-// Ensure api_keys extension columns exist (memoized)
 function ensureApiKeysColumns(db: ApiKeysDbLike) {
   if (_schemaChecked) return;
 
@@ -386,10 +379,6 @@ function ensureApiKeysColumns(db: ApiKeysDbLike) {
   }
 }
 
-/**
- * Initialize prepared statements (lazy initialization)
- * Re-creates statements if the underlying DB connection changed (HMR, backup restore).
- */
 let _stmtDb: ApiKeysDbLike | null = null;
 function getPreparedStatements(db: ApiKeysDbLike): ApiKeysStatements {
   ensureApiKeysColumns(db);
@@ -407,13 +396,13 @@ function getPreparedStatements(db: ApiKeysDbLike): ApiKeysStatements {
     _stmtGetAllKeys = db.prepare<ApiKeyRow>("SELECT * FROM api_keys ORDER BY created_at");
     _stmtGetKeyById = db.prepare<ApiKeyRow>("SELECT * FROM api_keys WHERE id = ?");
     _stmtValidateKey = db.prepare<JsonRecord>(
-      "SELECT id, expires_at, revoked_at, is_active, is_banned FROM api_keys WHERE key = ? OR key_hash = ?"
+      "SELECT id, expires_at, revoked_at, is_active, is_banned FROM api_keys WHERE key = ? OR key_hash = ?",
     );
     _stmtGetKeyMetadata = db.prepare<ApiKeyRow>(
-      "SELECT id, name, machine_id, allowed_models, blocked_models, allowed_combos, allowed_connections, allowed_quotas, no_log, auto_resolve, is_active, access_schedule, max_requests_per_day, max_requests_per_minute, throttle_delay_ms, max_sessions, revoked_at, expires_at, ip_allowlist, scopes, rate_limits, is_banned, key_hash, allowed_endpoints, stream_default_mode, disable_non_public_models, allow_usage_command, usage_limit_enabled, daily_usage_limit_usd, weekly_usage_limit_usd, chaos_mode_enabled, proxy_id FROM api_keys WHERE key = ? OR key_hash = ?"
+      "SELECT id, name, machine_id, allowed_models, blocked_models, allowed_combos, allowed_connections, allowed_quotas, no_log, auto_resolve, is_active, access_schedule, max_requests_per_day, max_requests_per_minute, throttle_delay_ms, max_sessions, revoked_at, expires_at, ip_allowlist, scopes, rate_limits, is_banned, key_hash, allowed_endpoints, stream_default_mode, disable_non_public_models, allow_usage_command, usage_limit_enabled, daily_usage_limit_usd, weekly_usage_limit_usd, chaos_mode_enabled, proxy_id FROM api_keys WHERE key = ? OR key_hash = ?",
     );
     _stmtInsertKey = db.prepare(
-      "INSERT INTO api_keys (id, name, key, machine_id, allowed_models, no_log, created_at, key_prefix, key_hash, scopes) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)"
+      "INSERT INTO api_keys (id, name, key, machine_id, allowed_models, no_log, created_at, key_prefix, key_hash, scopes) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
     );
     _stmtDeleteKey = db.prepare("DELETE FROM api_keys WHERE id = ?");
   }
@@ -466,7 +455,7 @@ export async function getApiKeys(limit?: number, offset?: number) {
     camelRow.allowedEndpoints = parseStringList((camelRow as JsonRecord).allowedEndpoints);
     camelRow.streamDefaultMode = parseStreamDefaultMode((camelRow as JsonRecord).streamDefaultMode);
     camelRow.disableNonPublicModels = parseDisableNonPublicModels(
-      (camelRow as JsonRecord).disableNonPublicModels
+      (camelRow as JsonRecord).disableNonPublicModels,
     );
     camelRow.allowUsageCommand = parseAllowUsageCommand((camelRow as JsonRecord).allowUsageCommand);
     camelRow.chaosModeEnabled = parseChaosModeEnabled((camelRow as JsonRecord).chaosModeEnabled);
@@ -509,7 +498,7 @@ export function getApiKeysCount(): number {
  * inactive, or banned key, and it never widens a key's allowedModels.
  */
 export async function pickApiKeyForInternalUse(
-  purpose: "combo-health-check" | "cloud-sync-verify" | "internal-probe" = "internal-probe"
+  purpose: "combo-health-check" | "cloud-sync-verify" | "internal-probe" = "internal-probe",
 ): Promise<string | null> {
   try {
     const keys = (await getApiKeys()) as Array<{
@@ -527,13 +516,13 @@ export async function pickApiKeyForInternalUse(
 
     // 1. Management-scoped key (preferred for any internal probe).
     const manageKey = keys.find(
-      (k) => isUsable(k) && Array.isArray(k.scopes) && k.scopes.includes("manage")
+      (k) => isUsable(k) && Array.isArray(k.scopes) && k.scopes.includes("manage"),
     );
     if (manageKey?.key) return manageKey.key;
 
     // 2. Allow-all key (empty allowedModels means no model restrictions).
     const allowAllKey = keys.find(
-      (k) => isUsable(k) && Array.isArray(k.allowedModels) && k.allowedModels.length === 0
+      (k) => isUsable(k) && Array.isArray(k.allowedModels) && k.allowedModels.length === 0,
     );
     if (allowAllKey?.key) return allowAllKey.key;
 
@@ -576,7 +565,7 @@ export async function getApiKeyById(id: string) {
   camelRow.allowedEndpoints = parseStringList((camelRow as JsonRecord).allowedEndpoints);
   camelRow.streamDefaultMode = parseStreamDefaultMode((camelRow as JsonRecord).streamDefaultMode);
   camelRow.disableNonPublicModels = parseDisableNonPublicModels(
-    (camelRow as JsonRecord).disableNonPublicModels
+    (camelRow as JsonRecord).disableNonPublicModels,
   );
   camelRow.allowUsageCommand = parseAllowUsageCommand((camelRow as JsonRecord).allowUsageCommand);
   camelRow.chaosModeEnabled = parseChaosModeEnabled((camelRow as JsonRecord).chaosModeEnabled);
@@ -633,7 +622,7 @@ export async function createApiKey(name: string, machineId: string, scopes: stri
     apiKey.createdAt,
     apiKey.key.slice(0, 12),
     await hashKey(apiKey.key),
-    JSON.stringify(scopes)
+    JSON.stringify(scopes),
   );
   setNoLog(apiKey.id, false);
 
@@ -655,7 +644,7 @@ export async function regenerateApiKey(id: string) {
 
   // Update in DB
   const updateStmt = db.prepare(
-    "UPDATE api_keys SET key = ?, key_hash = ?, key_prefix = ? WHERE id = ?"
+    "UPDATE api_keys SET key = ?, key_hash = ?, key_prefix = ? WHERE id = ?",
   );
   updateStmt.run(newKey, newHash, newPrefix, id);
 
@@ -707,7 +696,7 @@ export async function updateApiKeyPermissions(
         dailyUsageLimitUsd?: number | null;
         weeklyUsageLimitUsd?: number | null;
         chaosModeEnabled?: boolean;
-      }
+      },
 ) {
   const db = getDbInstance() as ApiKeysDbLike;
   getPreparedStatements(db);
@@ -1001,6 +990,16 @@ export async function updateApiKeyPermissions(
 
   if (changedRows === 0) return false;
 
+  const invalidatesModelCatalogCache =
+    normalized.allowedModels !== undefined ||
+    normalized.blockedModels !== undefined ||
+    allowedQuotasUpdate !== undefined ||
+    normalized.disableNonPublicModels !== undefined;
+
+  if (invalidatesModelCatalogCache) {
+    invalidateModelCatalogCache();
+  }
+
   const { logAuditEvent } = await import("@/lib/compliance");
 
   if (normalized.isBanned !== undefined) {
@@ -1094,7 +1093,7 @@ export async function revokeApiKey(id: string): Promise<boolean> {
 
   const result = db
     .prepare(
-      "UPDATE api_keys SET revoked_at = COALESCE(revoked_at, @ts), is_active = 0 WHERE id = @id"
+      "UPDATE api_keys SET revoked_at = COALESCE(revoked_at, @ts), is_active = 0 WHERE id = @id",
     )
     .run({ id, ts: new Date().toISOString() });
 
@@ -1223,7 +1222,7 @@ export async function validateApiKey(key: string | null | undefined) {
             revokedAt: row.revoked_at,
           }),
           "EX",
-          3600 // 1 hour cache
+          3600, // 1 hour cache
         );
       }
     } catch {
@@ -1240,7 +1239,7 @@ export async function validateApiKey(key: string | null | undefined) {
  * Get API key metadata with caching for performance
  */
 export async function getApiKeyMetadata(
-  key: string | null | undefined
+  key: string | null | undefined,
 ): Promise<ApiKeyMetadata | null> {
   if (!key || typeof key !== "string") return null;
 
@@ -1339,10 +1338,10 @@ export async function getApiKeyMetadata(
     blockedModels: parseAllowedModels(record.blocked_models ?? record.blockedModels),
     allowedCombos: parseAllowedCombos(record.allowed_combos ?? record.allowedCombos),
     allowedConnections: parseAllowedConnections(
-      record.allowed_connections ?? record.allowedConnections
+      record.allowed_connections ?? record.allowedConnections,
     ),
     allowedQuotas: parseAllowedQuotas(
-      (record as JsonRecord).allowed_quotas ?? (record as JsonRecord).allowedQuotas
+      (record as JsonRecord).allowed_quotas ?? (record as JsonRecord).allowedQuotas,
     ),
     noLog: parseNoLog(record.no_log ?? record.noLog),
     autoResolve: parseAutoResolve(record.auto_resolve ?? record.autoResolve),
@@ -1364,20 +1363,20 @@ export async function getApiKeyMetadata(
     proxyId:
       typeof record.proxy_id === "string" && record.proxy_id.trim() !== "" ? record.proxy_id : null,
     allowedEndpoints: parseStringList(
-      (record as JsonRecord).allowed_endpoints ?? (record as JsonRecord).allowedEndpoints
+      (record as JsonRecord).allowed_endpoints ?? (record as JsonRecord).allowedEndpoints,
     ),
     streamDefaultMode: parseStreamDefaultMode(
-      (record as JsonRecord).stream_default_mode ?? (record as JsonRecord).streamDefaultMode
+      (record as JsonRecord).stream_default_mode ?? (record as JsonRecord).streamDefaultMode,
     ),
     disableNonPublicModels: parseDisableNonPublicModels(
       (record as JsonRecord).disable_non_public_models ??
-        (record as JsonRecord).disableNonPublicModels
+        (record as JsonRecord).disableNonPublicModels,
     ),
     allowUsageCommand: parseAllowUsageCommand(
-      (record as JsonRecord).allow_usage_command ?? (record as JsonRecord).allowUsageCommand
+      (record as JsonRecord).allow_usage_command ?? (record as JsonRecord).allowUsageCommand,
     ),
     chaosModeEnabled: parseChaosModeEnabled(
-      (record as JsonRecord).chaos_mode_enabled ?? (record as JsonRecord).chaosModeEnabled
+      (record as JsonRecord).chaos_mode_enabled ?? (record as JsonRecord).chaosModeEnabled,
     ),
     ...parseApiKeyUsageLimitFields(record as JsonRecord),
   };
@@ -1403,7 +1402,7 @@ export async function getApiKeyMetadata(
  */
 export async function isModelAllowedForKey(
   key: string | null | undefined,
-  modelId: string | null | undefined
+  modelId: string | null | undefined,
 ) {
   // If no key provided, allow (request may be using different auth method like JWT)
   // If no modelId provided, deny (invalid request)
@@ -1413,12 +1412,13 @@ export async function isModelAllowedForKey(
   // Create cache key
   const cacheKey = `${key}:${modelId}`;
   const now = Date.now();
+  const catalogGeneration = getModelCatalogCacheVersion();
   const usesSettingDependentClaudeRouting = isPotentialUnprefixedClaudeCodeModel(modelId);
 
   // Check permission cache
-  const cached = _modelPermissionCache.get(cacheKey);
-  if (!usesSettingDependentClaudeRouting && cached && now - cached.timestamp < CACHE_TTL) {
-    return cached.allowed;
+  const cached = getCachedModelPermission(cacheKey, now, catalogGeneration);
+  if (!usesSettingDependentClaudeRouting && cached !== undefined) {
+    return cached;
   }
 
   const metadata = await getApiKeyMetadata(key);
@@ -1479,8 +1479,8 @@ export async function isModelAllowedForKey(
   }
   // Cache the result
   if (!usesSettingDependentClaudeRouting) {
-    evictIfNeeded(_modelPermissionCache);
-    _modelPermissionCache.set(cacheKey, { allowed, timestamp: now });
+    evictModelPermissionCache();
+    setCachedModelPermission(cacheKey, allowed, now, catalogGeneration);
   }
 
   return allowed;
@@ -1506,8 +1506,6 @@ function clearPreparedStatementCache() {
  */
 export function clearApiKeyCaches() {
   invalidateCaches();
-  _lastUsedUpdateCache.clear();
-  _modelPermissionCache.clear();
 }
 
 /**
diff --git a/src/lib/db/apiKeys/modelPermissionCache.ts b/src/lib/db/apiKeys/modelPermissionCache.ts
new file mode 100644
index 0000000000..d353f59b38
--- /dev/null
+++ b/src/lib/db/apiKeys/modelPermissionCache.ts
@@ -0,0 +1,62 @@
+const MODEL_PERMISSION_CACHE_TTL = 60 * 1000;
+
+interface ModelPermissionCacheValue {
+  allowed: boolean;
+  timestamp: number;
+  generation: number;
+}
+
+const _modelPermissionCache = new Map<string, ModelPermissionCacheValue>();
+
+function isFresh(
+  entry: ModelPermissionCacheValue,
+  now: number,
+  currentGeneration: number,
+): boolean {
+  if (entry.generation !== currentGeneration) return false;
+  if (now - entry.timestamp >= MODEL_PERMISSION_CACHE_TTL) return false;
+  return true;
+}
+
+export function getCachedModelPermission(
+  cacheKey: string,
+  now: number,
+  catalogGeneration: number,
+): boolean | undefined {
+  const entry = _modelPermissionCache.get(cacheKey);
+  if (!entry) return undefined;
+
+  if (!isFresh(entry, now, catalogGeneration)) {
+    _modelPermissionCache.delete(cacheKey);
+    return undefined;
+  }
+
+  return entry.allowed;
+}
+
+export function setCachedModelPermission(
+  cacheKey: string,
+  allowed: boolean,
+  now: number,
+  catalogGeneration: number,
+): void {
+  _modelPermissionCache.set(cacheKey, {
+    allowed,
+    timestamp: now,
+    generation: catalogGeneration,
+  });
+}
+
+export function evictModelPermissionCache(): void {
+  if (_modelPermissionCache.size <= 1000) return;
+  const entriesToRemove = Math.floor(1000 * 0.2);
+  let i = 0;
+  for (const key of _modelPermissionCache.keys()) {
+    if (i++ >= entriesToRemove) break;
+    _modelPermissionCache.delete(key);
+  }
+}
+
+export function clearModelPermissionCache(): void {
+  _modelPermissionCache.clear();
+}
diff --git a/src/lib/db/ccDiscoveryAliases.ts b/src/lib/db/ccDiscoveryAliases.ts
index 0eb46e2b34..2d16d2c673 100644
--- a/src/lib/db/ccDiscoveryAliases.ts
+++ b/src/lib/db/ccDiscoveryAliases.ts
@@ -22,6 +22,7 @@
 
 import { getFeatureFlagOverride } from "./featureFlags";
 import { getDbInstance } from "./core";
+import { finishModelCatalogWriteWithoutBackup } from "./models/modelCatalogWriteSignals";
 
 const NAMESPACE = "ccDiscoveryAliases";
 const FLAG_KEY = "EXPOSE_CC_DISCOVERY_ALIASES";
@@ -71,13 +72,15 @@ export function setCcAliasProviderSetting(providerId: string, v: CcAliasSetting)
   const key = providerKey(providerId);
   if (v === null) {
     db.prepare("DELETE FROM key_value WHERE namespace = ? AND key = ?").run(NAMESPACE, key);
+    finishModelCatalogWriteWithoutBackup();
     return;
   }
   db.prepare("INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES (?, ?, ?)").run(
     NAMESPACE,
     key,
-    v
+    v,
   );
+  finishModelCatalogWriteWithoutBackup();
 }
 
 export function getCcAliasModelSetting(providerId: string, modelId: string): CcAliasSetting {
@@ -91,19 +94,21 @@ export function getCcAliasModelSetting(providerId: string, modelId: string): CcA
 export function setCcAliasModelSetting(
   providerId: string,
   modelId: string,
-  v: CcAliasSetting
+  v: CcAliasSetting,
 ): void {
   const db = getDbInstance();
   const key = modelKey(providerId, modelId);
   if (v === null) {
     db.prepare("DELETE FROM key_value WHERE namespace = ? AND key = ?").run(NAMESPACE, key);
+    finishModelCatalogWriteWithoutBackup();
     return;
   }
   db.prepare("INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES (?, ?, ?)").run(
     NAMESPACE,
     key,
-    v
+    v,
   );
+  finishModelCatalogWriteWithoutBackup();
 }
 
 /**
diff --git a/src/lib/db/featureFlags.ts b/src/lib/db/featureFlags.ts
index 724543c354..ea28690498 100644
--- a/src/lib/db/featureFlags.ts
+++ b/src/lib/db/featureFlags.ts
@@ -8,9 +8,16 @@
 
 import { FEATURE_FLAG_DEFINITIONS } from "@/shared/constants/featureFlagDefinitions";
 import { getDbInstance } from "./core";
+import { finishModelCatalogWriteWithoutBackup } from "./models/modelCatalogWriteSignals";
 
 const NAMESPACE = "feature_flags";
 
+const CATALOG_RELEVANT_FEATURE_FLAGS = new Set([
+  "MODEL_CATALOG_INCLUDE_NAMES",
+  "MODELS_CATALOG_PREFIX_MODE",
+  "EXPOSE_CC_DISCOVERY_ALIASES",
+]);
+
 /**
  * Returns all feature flag overrides as a key→value map.
  */
@@ -53,15 +60,18 @@ export function setFeatureFlagOverride(key: string, value: string): void {
     !definition.enumValues.includes(value)
   ) {
     throw new Error(
-      `Invalid value "${value}" for enum flag ${key}. Allowed: ${definition.enumValues.join(", ")}`
+      `Invalid value "${value}" for enum flag ${key}. Allowed: ${definition.enumValues.join(", ")}`,
     );
   }
   const db = getDbInstance();
   db.prepare("INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES (?, ?, ?)").run(
     NAMESPACE,
     key,
-    value
+    value,
   );
+  if (CATALOG_RELEVANT_FEATURE_FLAGS.has(key)) {
+    finishModelCatalogWriteWithoutBackup();
+  }
 }
 
 /**
@@ -71,6 +81,9 @@ export function setFeatureFlagOverride(key: string, value: string): void {
 export function removeFeatureFlagOverride(key: string): void {
   const db = getDbInstance();
   db.prepare("DELETE FROM key_value WHERE namespace = ? AND key = ?").run(NAMESPACE, key);
+  if (CATALOG_RELEVANT_FEATURE_FLAGS.has(key)) {
+    finishModelCatalogWriteWithoutBackup();
+  }
 }
 
 /**
@@ -78,5 +91,13 @@ export function removeFeatureFlagOverride(key: string): void {
  */
 export function clearAllFeatureFlagOverrides(): void {
   const db = getDbInstance();
+  const hadRelevantOverride = Boolean(
+    db
+      .prepare("SELECT 1 FROM key_value WHERE namespace = ? AND key IN (?, ?, ?) LIMIT 1")
+      .get(NAMESPACE, ...Array.from(CATALOG_RELEVANT_FEATURE_FLAGS)),
+  );
   db.prepare("DELETE FROM key_value WHERE namespace = ?").run(NAMESPACE);
+  if (hadRelevantOverride) {
+    finishModelCatalogWriteWithoutBackup();
+  }
 }
diff --git a/src/lib/db/models.ts b/src/lib/db/models.ts
index 0f6499d737..4ad886cef1 100644
--- a/src/lib/db/models.ts
+++ b/src/lib/db/models.ts
@@ -4,17 +4,14 @@
  * models/; this file re-exports their public APIs for backward compatibility.
  */
 
-import { isRetiredGitHubCopilotModelId } from "@omniroute/open-sse/config/providers/registry/github/retiredModels.ts";
-
 import { getDbInstance } from "./core";
-import { backupDbFile } from "./backup";
 import { getProviderConnectionsCount } from "./providers";
-import { type JsonRecord, getKeyValue } from "./models/shared";
+import { type JsonRecord, asRecord, toNonEmptyString, getKeyValue } from "./models/shared";
 import {
-  normalizeSyncedAvailableModels,
-  type SyncedAvailableModel,
-  type SyncedAvailableModelInput,
-} from "./models/synced";
+  finishSyncedAvailableModelsWrite,
+  persistCanonicalSyncedAvailableModels,
+} from "./models/syncedAvailableModelPersistence";
+import { finishModelCatalogWriteWithBackup } from "./models/modelCatalogWriteSignals";
 import {
   readCompatList,
   writeCompatList,
@@ -47,7 +44,6 @@ export {
   deleteModelAliasesForProvider,
 } from "./models/aliases";
 export { getMitmAlias, setMitmAliasAll } from "./models/mitmAlias";
-export type { SyncedAvailableModel } from "./models/synced";
 
 // ──────────────── Custom Models ────────────────
 
@@ -109,7 +105,7 @@ export async function addCustomModel(
   tokenLimits: { inputTokenLimit?: number; outputTokenLimit?: number } = {},
   // #1904: optional manual vision-capability override for the "add custom model"
   // form — read back by getCustomVisionCapabilityFields() in the /v1/models catalog.
-  supportsVision?: boolean
+  supportsVision?: boolean,
 ) {
   const db = getDbInstance();
   const row = db
@@ -138,9 +134,9 @@ export async function addCustomModel(
   };
   models.push(model);
   db.prepare(
-    "INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES ('customModels', ?, ?)"
+    "INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES ('customModels', ?, ?)",
   ).run(providerId, JSON.stringify(models));
-  backupDbFile("pre-write");
+  finishModelCatalogWriteWithBackup();
   return model;
 }
 
@@ -162,7 +158,7 @@ export async function replaceCustomModels(
     supportsThinking?: boolean;
     targetFormat?: string;
   }>,
-  { allowEmpty = false }: { allowEmpty?: boolean } = {}
+  { allowEmpty = false }: { allowEmpty?: boolean } = {},
 ) {
   // Guard: skip destructive clear when the caller hasn't explicitly opted in.
   // This prevents callers from wiping manually added models when the
@@ -235,15 +231,15 @@ export async function replaceCustomModels(
 
   if (merged.length === 0) {
     db.prepare("DELETE FROM key_value WHERE namespace = 'customModels' AND key = ?").run(
-      providerId
+      providerId,
     );
   } else {
     db.prepare(
-      "INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES ('customModels', ?, ?)"
+      "INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES ('customModels', ?, ?)",
     ).run(providerId, JSON.stringify(merged));
   }
 
-  backupDbFile("pre-write");
+  finishModelCatalogWriteWithBackup();
   return merged;
 }
 
@@ -273,20 +269,20 @@ export async function deleteImportedCustomModels(providerId: string): Promise<st
 
   if (retained.length === 0) {
     db.prepare("DELETE FROM key_value WHERE namespace = 'customModels' AND key = ?").run(
-      providerId
+      providerId,
     );
   } else {
     db.prepare("UPDATE key_value SET value = ? WHERE namespace = 'customModels' AND key = ?").run(
       JSON.stringify(retained),
-      providerId
+      providerId,
     );
   }
 
   const removedIds = removed.flatMap((model) =>
-    typeof model.id === "string" && model.id ? [model.id] : []
+    typeof model.id === "string" && model.id ? [model.id] : [],
   );
   for (const modelId of removedIds) removeModelCompatOverride(providerId, modelId);
-  backupDbFile("pre-write");
+  finishModelCatalogWriteWithBackup();
   return removedIds;
 }
 
@@ -307,17 +303,17 @@ export async function removeCustomModel(providerId: string, modelId: string) {
 
   if (filtered.length === 0) {
     db.prepare("DELETE FROM key_value WHERE namespace = 'customModels' AND key = ?").run(
-      providerId
+      providerId,
     );
   } else {
     db.prepare("UPDATE key_value SET value = ? WHERE namespace = 'customModels' AND key = ?").run(
       JSON.stringify(filtered),
-      providerId
+      providerId,
     );
   }
 
   removeModelCompatOverride(providerId, modelId);
-  backupDbFile("pre-write");
+  finishModelCatalogWriteWithBackup();
   return true;
 }
 
@@ -326,12 +322,110 @@ export async function removeCustomModel(providerId: string, modelId: string) {
 // Each connection stores its own model list. Reads union across all connections
 // for a provider. Deleting a connection removes only its models.
 
+export interface SyncedAvailableModel {
+  id: string;
+  name: string;
+  source: "imported";
+  apiFormat?: string;
+  targetFormat?: string;
+  upstreamProtocol?: string;
+  supportedEndpoints?: string[];
+  supportedThinkingEfforts?: string[];
+  defaultThinkingEffort?: string;
+  inputTokenLimit?: number;
+  outputTokenLimit?: number;
+  description?: string;
+  supportsThinking?: boolean;
+  alwaysThinking?: boolean;
+  supportsTools?: boolean;
+  supportsVideo?: boolean;
+  // #4264: image-input capability captured at sync time (e.g. OpenRouter
+  // `architecture.input_modalities`/`modality`) so the catalog can surface vision.
+  supportsVision?: boolean;
+}
+
+type SyncedAvailableModelInput = Omit<SyncedAvailableModel, "source"> & {
+  source?: string;
+};
+
+function normalizeSyncedAvailableModel(model: unknown): SyncedAvailableModel | null {
+  const record = asRecord(model);
+  const id =
+    toNonEmptyString(record.id) || toNonEmptyString(record.name) || toNonEmptyString(record.model);
+  if (!id) return null;
+
+  const name =
+    toNonEmptyString(record.name) ||
+    toNonEmptyString(record.displayName) ||
+    toNonEmptyString(record.model) ||
+    id;
+  const supportedEndpoints = Array.isArray(record.supportedEndpoints)
+    ? Array.from(
+        new Set(
+          record.supportedEndpoints
+            .map((endpoint) => toNonEmptyString(endpoint))
+            .filter((endpoint): endpoint is string => Boolean(endpoint)),
+        ),
+      ).sort()
+    : undefined;
+
+  return {
+    id,
+    name,
+    source: "imported",
+    ...(toNonEmptyString(record.apiFormat)
+      ? { apiFormat: toNonEmptyString(record.apiFormat)! }
+      : {}),
+    ...(toNonEmptyString(record.targetFormat)
+      ? { targetFormat: toNonEmptyString(record.targetFormat)! }
+      : {}),
+    ...(toNonEmptyString(record.upstreamProtocol)
+      ? { upstreamProtocol: toNonEmptyString(record.upstreamProtocol)! }
+      : {}),
+    ...(supportedEndpoints && supportedEndpoints.length > 0 ? { supportedEndpoints } : {}),
+    ...(Array.isArray(record.supportedThinkingEfforts)
+      ? {
+          supportedThinkingEfforts: record.supportedThinkingEfforts.filter(
+            (effort): effort is string => typeof effort === "string" && effort.length > 0,
+          ),
+        }
+      : {}),
+    ...(toNonEmptyString(record.defaultThinkingEffort)
+      ? { defaultThinkingEffort: toNonEmptyString(record.defaultThinkingEffort)! }
+      : {}),
+    ...(typeof record.inputTokenLimit === "number"
+      ? { inputTokenLimit: record.inputTokenLimit }
+      : {}),
+    ...(typeof record.outputTokenLimit === "number"
+      ? { outputTokenLimit: record.outputTokenLimit }
+      : {}),
+    ...(typeof record.description === "string" ? { description: record.description } : {}),
+    ...(typeof record.supportsThinking === "boolean"
+      ? { supportsThinking: record.supportsThinking }
+      : {}),
+    ...(record.alwaysThinking === true ? { alwaysThinking: true } : {}),
+    ...(typeof record.supportsTools === "boolean" ? { supportsTools: record.supportsTools } : {}),
+    ...(typeof record.supportsVideo === "boolean" ? { supportsVideo: record.supportsVideo } : {}),
+    ...(record.supportsVision === true ? { supportsVision: true } : {}),
+  };
+}
+
+function normalizeSyncedAvailableModels(models: unknown): SyncedAvailableModel[] {
+  if (!Array.isArray(models)) return [];
+  const deduped = new Map<string, SyncedAvailableModel>();
+  for (const model of models) {
+    const normalized = normalizeSyncedAvailableModel(model);
+    if (normalized) deduped.set(normalized.id, normalized);
+  }
+  return Array.from(deduped.values());
+}
+
 /**
  * Get synced available models for a specific provider connection.
  */
 export async function getSyncedAvailableModelsForConnection(
   providerId: string,
-  connectionId: string
+  connectionId: string,
 ): Promise<SyncedAvailableModel[]> {
   const db = getDbInstance();
   const key = `${providerId}:${connectionId}`;
@@ -342,7 +436,7 @@ export async function getSyncedAvailableModelsForConnection(
   if (!value) return [];
   try {
     const models = JSON.parse(value);
-    return normalizeSyncedAvailableModels(models, providerId);
+    return normalizeSyncedAvailableModels(models);
   } catch {
     return [];
   }
@@ -352,19 +446,19 @@ export async function getSyncedAvailableModelsForConnection(
  * Get all synced available models for a provider, unioned across all connections.
  */
 export async function getSyncedAvailableModels(
-  providerId: string
+  providerId: string,
 ): Promise<SyncedAvailableModel[]> {
   const db = getDbInstance();
   const rows = db
     .prepare(
-      "SELECT key, value FROM key_value WHERE namespace = 'syncedAvailableModels' AND key LIKE ?"
+      "SELECT key, value FROM key_value WHERE namespace = 'syncedAvailableModels' AND key LIKE ?",
     )
     .all(`${providerId}:%`);
   const map = new Map<string, SyncedAvailableModel>();
   for (const row of rows) {
     const { key, value } = getKeyValue(row);
     if (!key || value === null) continue;
-    const models = normalizeSyncedAvailableModels(JSON.parse(value), providerId);
+    const models = normalizeSyncedAvailableModels(JSON.parse(value));
     for (const m of models) {
       if (m.id) map.set(m.id, m);
     }
@@ -376,13 +470,13 @@ export async function getSyncedAvailableModels(
  * Get synced available models for a provider grouped by connection id.
  */
 export async function getSyncedAvailableModelsByConnection(
-  providerId: string
+  providerId: string,
 ): Promise<Record<string, SyncedAvailableModel[]>> {
   const db = getDbInstance();
   const prefix = `${providerId}:`;
   const rows = db
     .prepare(
-      "SELECT key, value FROM key_value WHERE namespace = 'syncedAvailableModels' AND key LIKE ?"
+      "SELECT key, value FROM key_value WHERE namespace = 'syncedAvailableModels' AND key LIKE ?",
     )
     .all(`${prefix}%`);
   const result: Record<string, SyncedAvailableModel[]> = {};
@@ -391,7 +485,7 @@ export async function getSyncedAvailableModelsByConnection(
     if (!key || value === null || !key.startsWith(prefix)) continue;
     try {
       const connectionId = key.slice(prefix.length);
-      result[connectionId] = normalizeSyncedAvailableModels(JSON.parse(value), providerId);
+      result[connectionId] = normalizeSyncedAvailableModels(JSON.parse(value));
     } catch {
       // Ignore malformed legacy entries.
     }
@@ -416,7 +510,7 @@ export async function getAllSyncedAvailableModels(): Promise<
     if (!key || value === null) continue;
     const providerId = key.split(":")[0];
     if (!byProvider.has(providerId)) byProvider.set(providerId, new Map());
-    const models = normalizeSyncedAvailableModels(JSON.parse(value), providerId);
+    const models = normalizeSyncedAvailableModels(JSON.parse(value));
     const map = byProvider.get(providerId)!;
     for (const m of models) {
       if (m.id) map.set(m.id, m);
@@ -453,14 +547,13 @@ export async function getActiveProvidersWithSyncedModel(modelId: string): Promis
            json_extract(synced_model.value, '$.id'),
            json_extract(synced_model.value, '$.name'),
            json_extract(synced_model.value, '$.model')
-         ) = ?`
+         ) = ?`,
     )
     .all(modelId) as Array<{ provider?: unknown }>;
 
   return rows
     .map((row) => row.provider)
-    .filter((provider): provider is string => typeof provider === "string" && provider.length > 0)
-    .filter((provider) => !isRetiredGitHubCopilotModelId(provider, modelId));
+    .filter((provider): provider is string => typeof provider === "string" && provider.length > 0);
 }
 
 /**
@@ -470,9 +563,8 @@ export async function getActiveProvidersWithSyncedModel(modelId: string): Promis
 export async function replaceSyncedAvailableModelsForConnection(
   providerId: string,
   connectionId: string,
-  models: SyncedAvailableModelInput[]
+  models: SyncedAvailableModelInput[],
 ): Promise<SyncedAvailableModel[]> {
-  const db = getDbInstance();
   const key = `${providerId}:${connectionId}`;
   // #3199: drop ids the operator DELETED (trash) so a re-fetch does not re-import
   // a model that was explicitly removed.
@@ -481,19 +573,10 @@ export async function replaceSyncedAvailableModelsForConnection(
   // the synced store so they remain listed-but-hidden across re-syncs instead of
   // churning back on through the managed-alias path ("Auto Sync Enabling all
   // Models"). See getModelIsDeleted for the legacy-row caveat.
-  const normalizedModels = normalizeSyncedAvailableModels(models, providerId).filter(
-    (m) => !getModelIsDeleted(providerId, m.id)
+  const normalizedModels = normalizeSyncedAvailableModels(models).filter(
+    (m) => !getModelIsDeleted(providerId, m.id),
   );
-  if (normalizedModels.length === 0) {
-    db.prepare("DELETE FROM key_value WHERE namespace = 'syncedAvailableModels' AND key = ?").run(
-      key
-    );
-  } else {
-    db.prepare(
-      "INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES ('syncedAvailableModels', ?, ?)"
-    ).run(key, JSON.stringify(normalizedModels));
-  }
-  backupDbFile("pre-write");
+  persistCanonicalSyncedAvailableModels(key, normalizedModels, normalizeSyncedAvailableModels);
   // Return the full unioned list for the provider
   return getSyncedAvailableModels(providerId);
 }
@@ -504,13 +587,13 @@ export async function replaceSyncedAvailableModelsForConnection(
  */
 export async function removeSyncedAvailableModel(
   providerId: string,
-  modelId: string
+  modelId: string,
 ): Promise<boolean> {
   const db = getDbInstance();
   const prefix = `${providerId}:`;
   const rows = db
     .prepare(
-      "SELECT key, value FROM key_value WHERE namespace = 'syncedAvailableModels' AND key LIKE ?"
+      "SELECT key, value FROM key_value WHERE namespace = 'syncedAvailableModels' AND key LIKE ?",
     )
     .all(`${prefix}%`);
 
@@ -528,26 +611,25 @@ export async function removeSyncedAvailableModel(
         continue;
       }
 
-      const models = normalizeSyncedAvailableModels(parsedModels, providerId);
+      const models = normalizeSyncedAvailableModels(parsedModels);
       const filtered = models.filter((m) => m.id !== modelId);
       if (filtered.length !== models.length) {
         removedAny = true;
         if (filtered.length === 0) {
           db.prepare(
-            "DELETE FROM key_value WHERE namespace = 'syncedAvailableModels' AND key = ?"
+            "DELETE FROM key_value WHERE namespace = 'syncedAvailableModels' AND key = ?",
           ).run(key);
         } else {
           db.prepare(
-            "UPDATE key_value SET value = ? WHERE namespace = 'syncedAvailableModels' AND key = ?"
+            "UPDATE key_value SET value = ? WHERE namespace = 'syncedAvailableModels' AND key = ?",
           ).run(JSON.stringify(filtered), key);
         }
       }
     }
-
-    if (removedAny) backupDbFile("pre-write");
   });
 
   removeModel();
+  if (removedAny) finishSyncedAvailableModelsWrite();
   return removedAny;
 }
 
@@ -557,14 +639,14 @@ export async function removeSyncedAvailableModel(
  */
 export async function deleteSyncedAvailableModelsForConnection(
   providerId: string,
-  connectionId: string
+  connectionId: string,
 ): Promise<SyncedAvailableModel[]> {
   const db = getDbInstance();
   const key = `${providerId}:${connectionId}`;
-  db.prepare("DELETE FROM key_value WHERE namespace = 'syncedAvailableModels' AND key = ?").run(
-    key
-  );
-  backupDbFile("pre-write");
+  const result = db
+    .prepare("DELETE FROM key_value WHERE namespace = 'syncedAvailableModels' AND key = ?")
+    .run(key);
+  if (result.changes > 0) finishSyncedAvailableModelsWrite();
   return getSyncedAvailableModels(providerId);
 }
 
@@ -574,7 +656,7 @@ export async function deleteSyncedAvailableModelsForConnection(
  */
 export async function cleanupProviderModelsAfterConnectionDelete(
   providerId: string,
-  connectionId: string
+  connectionId: string,
 ): Promise<{
   remainingConnections: number;
   removedImportedModelIds: string[];
@@ -582,7 +664,7 @@ export async function cleanupProviderModelsAfterConnectionDelete(
 }> {
   const remainingSyncedModels = await deleteSyncedAvailableModelsForConnection(
     providerId,
-    connectionId
+    connectionId,
   );
   const remainingConnections = getProviderConnectionsCount({ provider: providerId });
   const removedImportedModelIds =
@@ -600,11 +682,12 @@ export async function deleteSyncedAvailableModelsForProvider(providerId: string)
   const keyPrefix = `${providerId}:`;
   const result = db
     .prepare(
-      "DELETE FROM key_value WHERE namespace = 'syncedAvailableModels' AND substr(key, 1, ?) = ?"
+      "DELETE FROM key_value WHERE namespace = 'syncedAvailableModels' AND substr(key, 1, ?) = ?",
     )
     .run(keyPrefix.length, keyPrefix);
-  backupDbFile("pre-write");
-  return Number(result.changes || 0);
+  const changes = Number(result.changes || 0);
+  if (changes > 0) finishSyncedAvailableModelsWrite();
+  return changes;
 }
 
 /**
@@ -613,7 +696,7 @@ export async function deleteSyncedAvailableModelsForProvider(providerId: string)
  */
 export async function pruneStaleSyncedAvailableModelsForProvider(
   providerId: string,
-  allowedConnectionIds: string[]
+  allowedConnectionIds: string[],
 ): Promise<number> {
   const db = getDbInstance();
   if (allowedConnectionIds.length === 0) {
@@ -624,11 +707,12 @@ export async function pruneStaleSyncedAvailableModelsForProvider(
   const allowedKeys = allowedConnectionIds.map((id) => `${providerId}:${id}`);
   const result = db
     .prepare(
-      `DELETE FROM key_value WHERE namespace = 'syncedAvailableModels' AND key LIKE ? AND key NOT IN (${placeholders})`
+      `DELETE FROM key_value WHERE namespace = 'syncedAvailableModels' AND key LIKE ? AND key NOT IN (${placeholders})`,
     )
     .run(`${keyPrefix}%`, ...allowedKeys);
-  backupDbFile("pre-write");
-  return Number(result.changes || 0);
+  const changes = Number(result.changes || 0);
+  if (changes > 0) finishSyncedAvailableModelsWrite();
+  return changes;
 }
 
 /**
@@ -640,7 +724,7 @@ export async function pruneStaleSyncedAvailableModelsForProvider(
 function applyTriStateBooleanOverride(
   next: JsonRecord,
   updates: Record<string, unknown>,
-  field: string
+  field: string,
 ): void {
   if (!Object.prototype.hasOwnProperty.call(updates, field)) return;
   if (updates[field] === null) {
@@ -653,7 +737,7 @@ function applyTriStateBooleanOverride(
 export async function updateCustomModel(
   providerId: string,
   modelId: string,
-  updates: Record<string, unknown> = {}
+  updates: Record<string, unknown> = {},
 ) {
   const db = getDbInstance();
   const row = db
@@ -681,7 +765,7 @@ export async function updateCustomModel(
       currentCompat,
       updates.compatByProtocol as Partial<
         Record<ModelCompatProtocolKey, Partial<ModelCompatPerProtocol>>
-      >
+      >,
     );
     if (!compatByProtocolHasEntries(mergedCompat)) mergedCompat = undefined;
   }
@@ -726,10 +810,10 @@ export async function updateCustomModel(
 
   db.prepare("UPDATE key_value SET value = ? WHERE namespace = 'customModels' AND key = ?").run(
     JSON.stringify(models),
-    providerId
+    providerId,
   );
 
-  backupDbFile("pre-write");
+  finishModelCatalogWriteWithBackup();
   return next;
 }
 
@@ -758,7 +842,7 @@ function getCustomModelRow(providerId: string, modelId: string): JsonRecord | nu
           typeof x === "object" &&
           !Array.isArray(x) &&
           typeof (x as { id?: string }).id === "string" &&
-          ((x as { id: string }).id as string).toLowerCase() === modelId.toLowerCase()
+          ((x as { id: string }).id as string).toLowerCase() === modelId.toLowerCase(),
       )) as JsonRecord | undefined;
     return m ?? null;
   } catch {
@@ -775,7 +859,7 @@ function getCustomModelRow(providerId: string, modelId: string): JsonRecord | nu
 export function getModelNormalizeToolCallId(
   providerId: string,
   modelId: string,
-  sourceFormat?: string | null
+  sourceFormat?: string | null,
 ): boolean {
   const m = getCustomModelRow(providerId, modelId);
   const protocol = sourceFormat && isCompatProtocolKey(sourceFormat) ? sourceFormat : null;
@@ -808,7 +892,7 @@ export function getModelNormalizeToolCallId(
 export function getModelPreserveOpenAIDeveloperRole(
   providerId: string,
   modelId: string,
-  sourceFormat?: string | null
+  sourceFormat?: string | null,
 ): boolean | undefined {
   const m = getCustomModelRow(providerId, modelId);
   const protocol = sourceFormat && isCompatProtocolKey(sourceFormat) ? sourceFormat : null;
@@ -857,45 +941,35 @@ export function getModelIsHidden(providerId: string, modelId: string): boolean {
  */
 export function getHiddenModelsByProvider(): Map<string, Set<string>> {
   const db = getDbInstance();
-  const visibilityByProvider = new Map<string, Map<string, boolean>>();
+  const result = new Map<string, Set<string>>();
+
+  // Query all rows from key_value for both namespaces
   const rows = db
     .prepare(
-      "SELECT namespace, key, value FROM key_value WHERE namespace IN ('modelCompatOverrides', 'customModels')"
+      "SELECT key, value FROM key_value WHERE namespace IN ('modelCompatOverrides', 'customModels')",
     )
-    .all() as Array<{ namespace: string; key: string; value: string | null }>;
+    .all() as Array<{ key: string; value: string | null }>;
 
-  for (const namespace of ["modelCompatOverrides", "customModels"]) {
-    for (const row of rows) {
-      if (row.namespace !== namespace || !row.value) continue;
-      try {
-        const parsed = JSON.parse(row.value);
-        if (!Array.isArray(parsed)) continue;
-        for (const entry of parsed) {
-          if (!entry || typeof entry !== "object") continue;
-          const modelId = (entry as { id?: unknown }).id;
-          if (typeof modelId !== "string" || modelId.length === 0) continue;
-          if (!Object.prototype.hasOwnProperty.call(entry, "isHidden")) continue;
-          let visibility = visibilityByProvider.get(row.key);
-          if (!visibility) {
-            visibility = new Map<string, boolean>();
-            visibilityByProvider.set(row.key, visibility);
+  for (const row of rows) {
+    if (!row.value) continue;
+    try {
+      const parsed = JSON.parse(row.value);
+      if (!Array.isArray(parsed)) continue;
+      for (const entry of parsed) {
+        if (entry && typeof entry === "object" && entry.isHidden) {
+          const modelId = entry.id;
+          if (typeof modelId === "string" && modelId.length > 0) {
+            if (!result.has(row.key)) result.set(row.key, new Set());
+            result.get(row.key)!.add(modelId);
           }
-          visibility.set(modelId, Boolean((entry as { isHidden?: unknown }).isHidden));
         }
-      } catch {
-        // Skip malformed entries
       }
+    } catch {
+      // Skip malformed entries
     }
   }
 
-  return new Map(
-    [...visibilityByProvider].flatMap(([providerId, visibility]) => {
-      const hiddenModels = [...visibility].flatMap(([modelId, isHidden]) =>
-        isHidden ? [modelId] : []
-      );
-      return hiddenModels.length > 0 ? [[providerId, new Set(hiddenModels)] as const] : [];
-    })
-  );
+  return result;
 }
 
 /**
@@ -960,7 +1034,7 @@ export function setModelIsHidden(providerId: string, modelId: string, hidden: bo
 
 function readUpstreamFromJsonRecord(
   row: JsonRecord | null | undefined,
-  key: "upstreamHeaders"
+  key: "upstreamHeaders",
 ): Record<string, string> | undefined {
   if (!row) return undefined;
   const raw = row[key];
@@ -982,7 +1056,7 @@ function readUpstreamFromJsonRecord(
 export function getModelUpstreamExtraHeaders(
   providerId: string,
   modelId: string,
-  sourceFormat?: string | null
+  sourceFormat?: string | null,
 ): Record<string, string> {
   const protocol = sourceFormat && isCompatProtocolKey(sourceFormat) ? sourceFormat : null;
   const m = getCustomModelRow(providerId, modelId);
@@ -1009,8 +1083,8 @@ export function getModelUpstreamExtraHeaders(
     Object.assign(
       base,
       sanitizeUpstreamHeadersMap(
-        co.compatByProtocol[protocol]!.upstreamHeaders as Record<string, unknown>
-      )
+        co.compatByProtocol[protocol]!.upstreamHeaders as Record<string, unknown>,
+      ),
     );
   }
   return base;
diff --git a/src/lib/db/models/aliases.ts b/src/lib/db/models/aliases.ts
index b88e15d7c1..b28d95e31d 100644
--- a/src/lib/db/models/aliases.ts
+++ b/src/lib/db/models/aliases.ts
@@ -1,8 +1,8 @@
 /** db/models/aliases.ts — model alias CRUD (modelAliases namespace). */
 
 import { getDbInstance } from "../core";
-import { backupDbFile } from "../backup";
 import { getKeyValue } from "./shared";
+import { finishModelCatalogWriteWithBackup } from "./modelCatalogWriteSignals";
 
 export async function getModelAliases() {
   const db = getDbInstance();
@@ -21,15 +21,15 @@ export async function getModelAliases() {
 export async function setModelAlias(alias: string, model: unknown) {
   const db = getDbInstance();
   db.prepare(
-    "INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES ('modelAliases', ?, ?)"
+    "INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES ('modelAliases', ?, ?)",
   ).run(alias, JSON.stringify(model));
-  backupDbFile("pre-write");
+  finishModelCatalogWriteWithBackup();
 }
 
 export async function deleteModelAlias(alias: string) {
   const db = getDbInstance();
   db.prepare("DELETE FROM key_value WHERE namespace = 'modelAliases' AND key = ?").run(alias);
-  backupDbFile("pre-write");
+  finishModelCatalogWriteWithBackup();
 }
 
 /**
diff --git a/src/lib/db/models/compat.ts b/src/lib/db/models/compat.ts
index 54b05ba3a6..eba83f8703 100644
--- a/src/lib/db/models/compat.ts
+++ b/src/lib/db/models/compat.ts
@@ -1,13 +1,13 @@
 /** db/models/compat.ts — model-compat overrides (normalizeToolCallId, per-protocol flags, upstream headers). */
 
 import { getDbInstance } from "../core";
-import { backupDbFile } from "../backup";
 import {
   MODEL_COMPAT_PROTOCOL_KEYS,
   type ModelCompatProtocolKey,
 } from "@/shared/constants/modelCompat";
 import { isForbiddenUpstreamHeaderName } from "@/shared/constants/upstreamHeaders";
 import { getKeyValue } from "./shared";
+import { finishModelCatalogWriteWithBackup } from "./modelCatalogWriteSignals";
 
 /** Built-in / alias models: tool-call + developer-role flags without a full custom row */
 const MODEL_COMPAT_NAMESPACE = "modelCompatOverrides";
@@ -42,7 +42,7 @@ function isValidUpstreamHeaderName(k: string): boolean {
 
 /** Sanitize user-provided upstream header map (used when persisting and when reading for requests). */
 export function sanitizeUpstreamHeadersMap(
-  raw: Record<string, unknown> | null | undefined
+  raw: Record<string, unknown> | null | undefined,
 ): Record<string, string> {
   const out: Record<string, string> = {};
   if (!raw || typeof raw !== "object") return out;
@@ -66,7 +66,7 @@ export function sanitizeUpstreamHeadersMap(
 
 export function deepMergeCompatByProtocol(
   prev: CompatByProtocolMap | undefined,
-  patch: Partial<Record<ModelCompatProtocolKey, Partial<ModelCompatPerProtocol>>>
+  patch: Partial<Record<ModelCompatProtocolKey, Partial<ModelCompatPerProtocol>>>,
 ): CompatByProtocolMap {
   const out: CompatByProtocolMap = { ...(prev || {}) };
   for (const key of Object.keys(patch) as ModelCompatProtocolKey[]) {
@@ -140,16 +140,16 @@ export function writeCompatList(providerId: string, list: ModelCompatOverride[])
   if (list.length === 0) {
     db.prepare("DELETE FROM key_value WHERE namespace = ? AND key = ?").run(
       MODEL_COMPAT_NAMESPACE,
-      providerId
+      providerId,
     );
   } else {
     db.prepare("INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES (?, ?, ?)").run(
       MODEL_COMPAT_NAMESPACE,
       providerId,
-      JSON.stringify(list)
+      JSON.stringify(list),
     );
   }
-  backupDbFile("pre-write");
+  finishModelCatalogWriteWithBackup();
 }
 
 export function getModelCompatOverrides(providerId: string): ModelCompatOverride[] {
@@ -178,7 +178,7 @@ export function compatByProtocolHasEntries(map: CompatByProtocolMap | undefined)
 export function mergeModelCompatOverride(
   providerId: string,
   modelId: string,
-  patch: ModelCompatPatch
+  patch: ModelCompatPatch,
 ) {
   const list = readCompatList(providerId);
   const idx = list.findIndex((e) => e.id === modelId);
diff --git a/src/lib/db/models/modelCatalogWriteSignals.ts b/src/lib/db/models/modelCatalogWriteSignals.ts
new file mode 100644
index 0000000000..0903839baa
--- /dev/null
+++ b/src/lib/db/models/modelCatalogWriteSignals.ts
@@ -0,0 +1,11 @@
+import { backupDbFile } from "../backup";
+import { invalidateModelCatalogCache } from "../readCache";
+
+export function finishModelCatalogWriteWithBackup(): void {
+  backupDbFile("pre-write");
+  invalidateModelCatalogCache();
+}
+
+export function finishModelCatalogWriteWithoutBackup(): void {
+  invalidateModelCatalogCache();
+}
diff --git a/src/lib/db/models/syncedAvailableModelPersistence.ts b/src/lib/db/models/syncedAvailableModelPersistence.ts
new file mode 100644
index 0000000000..7e8d13a142
--- /dev/null
+++ b/src/lib/db/models/syncedAvailableModelPersistence.ts
@@ -0,0 +1,52 @@
+/** Canonical comparison and write helpers for connection-scoped synced model catalogs. */
+
+import { backupDbFile } from "../backup";
+import { getDbInstance } from "../core";
+import { invalidateModelCatalogCache } from "../readCache";
+import { getKeyValue } from "./shared";
+
+type ModelNormalizer<T> = (models: unknown) => T[];
+
+export function finishSyncedAvailableModelsWrite(): void {
+  backupDbFile("pre-write");
+  invalidateModelCatalogCache();
+}
+
+export function persistCanonicalSyncedAvailableModels<T>(
+  key: string,
+  normalizedModels: T[],
+  normalizeModels: ModelNormalizer<T>
+): boolean {
+  const db = getDbInstance();
+  const existingRow = db
+    .prepare("SELECT value FROM key_value WHERE namespace = 'syncedAvailableModels' AND key = ?")
+    .get(key);
+  const existingValue = getKeyValue(existingRow).value;
+  let existingModels: T[] | null = null;
+  if (existingValue !== null) {
+    try {
+      existingModels = normalizeModels(JSON.parse(existingValue));
+    } catch {
+      existingModels = null;
+    }
+  }
+
+  const unchanged =
+    (normalizedModels.length > 0 &&
+      existingModels !== null &&
+      JSON.stringify(existingModels) === JSON.stringify(normalizedModels)) ||
+    (normalizedModels.length === 0 && existingValue === null);
+  if (unchanged) return false;
+
+  if (normalizedModels.length === 0) {
+    db.prepare("DELETE FROM key_value WHERE namespace = 'syncedAvailableModels' AND key = ?").run(
+      key
+    );
+  } else {
+    db.prepare(
+      "INSERT OR REPLACE INTO key_value (namespace, key, value) VALUES ('syncedAvailableModels', ?, ?)"
+    ).run(key, JSON.stringify(normalizedModels));
+  }
+  finishSyncedAvailableModelsWrite();
+  return true;
+}
diff --git a/src/lib/db/quotaGroups.ts b/src/lib/db/quotaGroups.ts
index b944828394..f2f21966b9 100644
--- a/src/lib/db/quotaGroups.ts
+++ b/src/lib/db/quotaGroups.ts
@@ -9,6 +9,7 @@
  */
 
 import { getDbInstance } from "./core";
+import { invalidateModelCatalogCache } from "./readCache";
 
 // ---------------------------------------------------------------------------
 // Types
@@ -113,7 +114,11 @@ export function listGroups(): QuotaGroup[] {
  */
 export function renameGroup(id: string, name: string): boolean {
   const result = getDb().prepare("UPDATE quota_groups SET name = ? WHERE id = ?").run(name, id);
-  return result.changes > 0;
+  if (result.changes > 0) {
+    invalidateModelCatalogCache();
+    return true;
+  }
+  return false;
 }
 
 /**
@@ -130,7 +135,7 @@ export function deleteGroup(id: string): boolean {
   // Protect the seed group.
   if (id === "group-demo") {
     throw new Error(
-      "Cannot delete the protected seed group 'group-demo'. Reassign its pools to another group first."
+      "Cannot delete the protected seed group 'group-demo'. Reassign its pools to another group first.",
     );
   }
 
diff --git a/src/lib/db/quotaPools.ts b/src/lib/db/quotaPools.ts
index b054f15c75..a26a4bc6b0 100644
--- a/src/lib/db/quotaPools.ts
+++ b/src/lib/db/quotaPools.ts
@@ -9,6 +9,8 @@
  */
 
 import { getDbInstance } from "./core";
+import { clearApiKeyCaches } from "./apiKeys";
+import { invalidateModelCatalogCache } from "./readCache";
 // Phase B2: auto-mint/prune quotaShared-* combos when pool allocations change.
 // Imported lazily (dynamic import in the hook) to avoid circular-dependency
 // risk between db/ and quota/ modules. The import is fire-and-forget; combo
@@ -30,7 +32,7 @@ async function removeQuotaCombosGuarded(poolId: string): Promise<void> {
   } catch (err) {
     console.warn(
       "[quota-pools] removeQuotaCombosForPool failed (non-fatal):",
-      (err as Error)?.message
+      (err as Error)?.message,
     );
   }
 }
@@ -125,7 +127,7 @@ function assertSingleProvider(connectionIds: string[]): void {
   const providers = rows.map((r) => r.provider).filter(Boolean);
   if (new Set(providers).size > 1) {
     throw new Error(
-      `A quota pool must use a single provider (got: ${[...new Set(providers)].join(", ")})`
+      `A quota pool must use a single provider (got: ${[...new Set(providers)].join(", ")})`,
     );
   }
 }
@@ -179,7 +181,7 @@ interface PoolConnectionRow {
 function getConnectionIds(poolId: string, fallbackConnectionId: string): string[] {
   const rows = getDb()
     .prepare<PoolConnectionRow>(
-      "SELECT connection_id FROM quota_pool_connections WHERE pool_id = ? ORDER BY created_at ASC"
+      "SELECT connection_id FROM quota_pool_connections WHERE pool_id = ? ORDER BY created_at ASC",
     )
     .all(poolId);
   if (rows.length > 0) {
@@ -210,7 +212,7 @@ function batchBuildPools(rows: PoolRow[]): QuotaPool[] {
   // Batch allocations: 1 query for all pools
   const allocRows = db
     .prepare<AllocationRow>(
-      `SELECT pool_id, api_key_id, weight, cap_value, cap_unit, policy FROM quota_allocations WHERE pool_id IN (${ph})`
+      `SELECT pool_id, api_key_id, weight, cap_value, cap_unit, policy FROM quota_allocations WHERE pool_id IN (${ph})`,
     )
     .all(...poolIds);
   const allocsByPool = new Map<string, AllocationRow[]>();
@@ -226,7 +228,7 @@ function batchBuildPools(rows: PoolRow[]): QuotaPool[] {
   // Batch connections: 1 query for all pools
   const connRows = db
     .prepare<{ pool_id: string; connection_id: string }>(
-      `SELECT pool_id, connection_id FROM quota_pool_connections WHERE pool_id IN (${ph}) ORDER BY created_at ASC`
+      `SELECT pool_id, connection_id FROM quota_pool_connections WHERE pool_id IN (${ph}) ORDER BY created_at ASC`,
     )
     .all(...poolIds);
   const connsByPool = new Map<string, string[]>();
@@ -253,7 +255,7 @@ function batchBuildPools(rows: PoolRow[]): QuotaPool[] {
 function getAllocations(poolId: string): PoolAllocation[] {
   const rows = getDb()
     .prepare<AllocationRow>(
-      "SELECT pool_id, api_key_id, weight, cap_value, cap_unit, policy FROM quota_allocations WHERE pool_id = ?"
+      "SELECT pool_id, api_key_id, weight, cap_value, cap_unit, policy FROM quota_allocations WHERE pool_id = ?",
     )
     .all(poolId);
   return rows.map(rowToAllocation);
@@ -324,7 +326,7 @@ export function listPools(options?: { limit?: number; offset?: number }): {
 export function getPool(id: string): QuotaPool | null {
   const row = getDb()
     .prepare<PoolRow>(
-      "SELECT id, connection_id, name, group_id, created_at FROM quota_pools WHERE id = ?"
+      "SELECT id, connection_id, name, group_id, created_at FROM quota_pools WHERE id = ?",
     )
     .get(id);
   if (!row) return null;
@@ -358,12 +360,12 @@ export function createPool(input: PoolCreate): QuotaPool {
   const doCreate = database.transaction(() => {
     database
       .prepare(
-        "INSERT INTO quota_pools (id, connection_id, name, group_id, created_at) VALUES (?, ?, ?, ?, ?)"
+        "INSERT INTO quota_pools (id, connection_id, name, group_id, created_at) VALUES (?, ?, ?, ?, ?)",
       )
       .run(id, primaryConnectionId, input.name, groupId, now);
 
     const insertConn = database.prepare(
-      "INSERT OR IGNORE INTO quota_pool_connections (pool_id, connection_id) VALUES (?, ?)"
+      "INSERT OR IGNORE INTO quota_pool_connections (pool_id, connection_id) VALUES (?, ?)",
     );
     for (const connId of members) {
       insertConn.run(id, connId);
@@ -372,7 +374,7 @@ export function createPool(input: PoolCreate): QuotaPool {
     if (input.allocations && input.allocations.length > 0) {
       const insertAlloc = database.prepare(
         `INSERT INTO quota_allocations (pool_id, api_key_id, weight, cap_value, cap_unit, policy)
-         VALUES (?, ?, ?, ?, ?, ?)`
+         VALUES (?, ?, ?, ?, ?, ?)`,
       );
       for (const alloc of input.allocations) {
         insertAlloc.run(
@@ -381,7 +383,7 @@ export function createPool(input: PoolCreate): QuotaPool {
           alloc.weight,
           alloc.capValue ?? null,
           alloc.capUnit ?? null,
-          alloc.policy
+          alloc.policy,
         );
       }
     }
@@ -396,12 +398,14 @@ export function createPool(input: PoolCreate): QuotaPool {
       group_id: groupId,
       created_at: now,
     },
-    getAllocations(id)
+    getAllocations(id),
   );
 
   // Phase B2: fire-and-forget combo sync; failures are logged but never thrown.
   void syncQuotaCombosGuarded(id);
 
+  invalidateModelCatalogCache();
+
   return result;
 }
 
@@ -415,7 +419,7 @@ export function updatePool(id: string, input: PoolUpdate): QuotaPool | null {
   const database = getDb();
   const existing = database
     .prepare<PoolRow>(
-      "SELECT id, connection_id, name, group_id, created_at FROM quota_pools WHERE id = ?"
+      "SELECT id, connection_id, name, group_id, created_at FROM quota_pools WHERE id = ?",
     )
     .get(id);
   if (!existing) return null;
@@ -441,7 +445,7 @@ export function updatePool(id: string, input: PoolUpdate): QuotaPool | null {
       // Replace join rows.
       database.prepare("DELETE FROM quota_pool_connections WHERE pool_id = ?").run(id);
       const insertConn = database.prepare(
-        "INSERT OR IGNORE INTO quota_pool_connections (pool_id, connection_id) VALUES (?, ?)"
+        "INSERT OR IGNORE INTO quota_pool_connections (pool_id, connection_id) VALUES (?, ?)",
       );
       for (const connId of input.connectionIds) {
         insertConn.run(id, connId);
@@ -456,7 +460,7 @@ export function updatePool(id: string, input: PoolUpdate): QuotaPool | null {
       database.prepare("DELETE FROM quota_allocations WHERE pool_id = ?").run(id);
       const insertAlloc = database.prepare(
         `INSERT INTO quota_allocations (pool_id, api_key_id, weight, cap_value, cap_unit, policy)
-         VALUES (?, ?, ?, ?, ?, ?)`
+         VALUES (?, ?, ?, ?, ?, ?)`,
       );
       for (const alloc of input.allocations) {
         insertAlloc.run(
@@ -465,7 +469,7 @@ export function updatePool(id: string, input: PoolUpdate): QuotaPool | null {
           alloc.weight,
           alloc.capValue ?? null,
           alloc.capUnit ?? null,
-          alloc.policy
+          alloc.policy,
         );
       }
     }
@@ -477,6 +481,8 @@ export function updatePool(id: string, input: PoolUpdate): QuotaPool | null {
   // Phase B2: fire-and-forget combo sync; failures are logged but never thrown.
   void syncQuotaCombosGuarded(id);
 
+  invalidateModelCatalogCache();
+
   return result;
 }
 
@@ -500,13 +506,20 @@ export function deletePool(id: string): boolean {
          (SELECT json_group_array(value) FROM json_each(api_keys.allowed_quotas) WHERE value != ?),
          '[]')
        WHERE allowed_quotas IS NOT NULL AND allowed_quotas != '[]'
-         AND EXISTS (SELECT 1 FROM json_each(api_keys.allowed_quotas) WHERE value = ?)`
+         AND EXISTS (SELECT 1 FROM json_each(api_keys.allowed_quotas) WHERE value = ?)`,
       )
       .run(id, id);
     return database.prepare("DELETE FROM quota_pools WHERE id = ?").run(id);
   });
   const result = doDelete();
-  return result.changes > 0;
+  if (result.changes <= 0) return false;
+
+  // Direct rewrite of key permission metadata happens above; clear API-key
+  // caches so any primed permission entries pick up the new allowed_quotas set.
+  clearApiKeyCaches();
+  invalidateModelCatalogCache();
+
+  return true;
 }
 
 /**
@@ -552,7 +565,7 @@ export function upsertAllocations(poolId: string, allocations: PoolAllocation[])
   // without requiring a manual re-save. Persists the normalized weights.
   const totalWeight = allocations.reduce(
     (s, a) => s + (Number.isFinite(a.weight) ? a.weight : 0),
-    0
+    0,
   );
   const normalizedAllocations =
     totalWeight === 0 && allocations.length > 0
@@ -563,7 +576,7 @@ export function upsertAllocations(poolId: string, allocations: PoolAllocation[])
   // Defensive: fall back to [poolId] (single-pool semantics) if pool not found.
   const targetPool = database
     .prepare<PoolRow>(
-      "SELECT id, connection_id, name, group_id, created_at FROM quota_pools WHERE id = ?"
+      "SELECT id, connection_id, name, group_id, created_at FROM quota_pools WHERE id = ?",
     )
     .get(poolId);
 
@@ -582,7 +595,7 @@ export function upsertAllocations(poolId: string, allocations: PoolAllocation[])
   const doUpsert = database.transaction(() => {
     const insert = database.prepare(
       `INSERT INTO quota_allocations (pool_id, api_key_id, weight, cap_value, cap_unit, policy)
-       VALUES (?, ?, ?, ?, ?, ?)`
+       VALUES (?, ?, ?, ?, ?, ?)`,
     );
     for (const pid of poolIdsInGroup) {
       database.prepare("DELETE FROM quota_allocations WHERE pool_id = ?").run(pid);
@@ -593,7 +606,7 @@ export function upsertAllocations(poolId: string, allocations: PoolAllocation[])
           alloc.weight,
           alloc.capValue ?? null,
           alloc.capUnit ?? null,
-          alloc.policy
+          alloc.policy,
         );
       }
     }
@@ -610,13 +623,13 @@ export function upsertAllocations(poolId: string, allocations: PoolAllocation[])
  * Returns pairs of { poolId, allocation }.
  */
 export function listAllocationsForApiKey(
-  apiKeyId: string
+  apiKeyId: string,
 ): Array<{ poolId: string; allocation: PoolAllocation }> {
   const rows = getDb()
     .prepare<AllocationRow>(
       `SELECT pool_id, api_key_id, weight, cap_value, cap_unit, policy
        FROM quota_allocations
-       WHERE api_key_id = ?`
+       WHERE api_key_id = ?`,
     )
     .all(apiKeyId);
   return rows.map((row) => ({ poolId: row.pool_id, allocation: rowToAllocation(row) }));
diff --git a/src/lib/db/readCache.ts b/src/lib/db/readCache.ts
index 79fff8c2d2..13dcaaaf85 100644
--- a/src/lib/db/readCache.ts
+++ b/src/lib/db/readCache.ts
@@ -234,26 +234,29 @@ export function getCombosCacheVersion(): number {
 
 // ──────────────── Model Catalog Cache Invalidation Signal ────────────────
 //
-// #6408 added a request-shape-keyed (prefix/isCodex/apiKey) TTL cache around the
-// unified /v1/models builder (src/app/api/v1/models/catalog.ts) to coalesce
-// concurrent/bursty GETs. That cache key does not vary with the underlying DB
-// state the builder reads (connections, settings, combos), so a write followed by
-// a read within the ~1.5s TTL replayed the pre-write response. Same import-cycle
+// #6408 added a request-shape-keyed (prefix/isCodex/apiKey/configuredOnly) TTL
+// cache around the unified /v1/models builder (src/app/api/v1/models/catalog.ts)
+// to coalesce concurrent/bursty GETs. That cache key does not vary with the
+// underlying DB state the builder reads (connections, settings, combos), so
+// writes need an explicit invalidation signal. Same import-cycle
 // constraint as combosCacheVersion above (a db module must not import the route
-// module) — catalog.ts instead compares this version on every access and drops its
-// whole cache the moment it moves, so any write that calls invalidateDbCache() makes
-// the next read miss immediately instead of waiting out the TTL.
+// module): catalogCache.ts compares this version on every access and builder
+// completion, then hard-invalidates snapshots and old-generation work when it moves.
 let modelCatalogCacheVersion = 0;
 
 /**
- * Current model-catalog-cache version. `getUnifiedModelsResponse()` folds this
- * into its response cache key; a change means settings/connections/combos were
- * written since the cache was populated and the cached body is stale.
+ * Current model-catalog-cache version. A change means catalog-backed state was
+ * written and the next read must synchronously build the new generation.
  */
 export function getModelCatalogCacheVersion(): number {
   return modelCatalogCacheVersion;
 }
 
+/** Invalidate only the unified model catalog response cache. */
+export function invalidateModelCatalogCache(): void {
+  modelCatalogCacheVersion++;
+}
+
 /**
  * Invalidate caches (call after writes to any of: settings, pricing,
  * connections, combos, nodes).
diff --git a/tests/integration/v1-models-swr-response-flush-8728.test.ts b/tests/integration/v1-models-swr-response-flush-8728.test.ts
new file mode 100644
index 0000000000..60aa72c894
--- /dev/null
+++ b/tests/integration/v1-models-swr-response-flush-8728.test.ts
@@ -0,0 +1,183 @@
+import assert from "node:assert/strict";
+import { spawn } from "node:child_process";
+import fs from "node:fs";
+import http from "node:http";
+import os from "node:os";
+import path from "node:path";
+import test from "node:test";
+import { fileURLToPath } from "node:url";
+
+const CACHE_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-swr-cache-8728-"));
+process.env.DATA_DIR = CACHE_DATA_DIR;
+
+const catalogCache = await import("../../src/app/api/v1/models/catalogCache.ts");
+const REPO_ROOT = fileURLToPath(new URL("../..", import.meta.url));
+const BLOCK_MS = 300;
+
+function listen(server: http.Server, socketPath: string): Promise<void> {
+  return new Promise((resolve, reject) => {
+    server.once("error", reject);
+    server.listen(socketPath, resolve);
+  });
+}
+
+function close(server: http.Server): Promise<void> {
+  return new Promise((resolve, reject) => {
+    server.close((error) => (error ? reject(error) : resolve()));
+  });
+}
+
+function fetchFromExternalClient(
+  socketPath: string
+): Promise<{ body: string; receivedAt: number }> {
+  const script = [
+    'import http from "node:http";',
+    "const chunks = [];",
+    "const request = http.request({ socketPath: process.argv[1], path: '/v1/models' }, (response) => {",
+    "  response.on('data', (chunk) => chunks.push(chunk));",
+    "  response.on('end', () => {",
+    "    const body = Buffer.concat(chunks).toString('utf8');",
+    "    process.stdout.write(JSON.stringify({ body, receivedAt: Date.now() }));",
+    "  });",
+    "});",
+    "request.on('error', (error) => { throw error; });",
+    "request.end();",
+  ].join("\n");
+  const child = spawn(process.execPath, ["--input-type=module", "-e", script, socketPath], {
+    stdio: ["ignore", "pipe", "pipe"],
+  });
+
+  return new Promise((resolve, reject) => {
+    let stdout = "";
+    let stderr = "";
+    child.stdout.on("data", (chunk) => {
+      stdout += String(chunk);
+    });
+    child.stderr.on("data", (chunk) => {
+      stderr += String(chunk);
+    });
+    child.once("error", reject);
+    child.once("exit", (code) => {
+      if (code !== 0) {
+        reject(new Error(`external fetch exited ${code}: ${stderr}`));
+        return;
+      }
+      resolve(JSON.parse(stdout));
+    });
+  });
+}
+
+function productionShapedSynchronousRefresh() {
+  const models = Array.from({ length: 4_000 }, (_, index) => ({
+    id: `provider/model-${index}`,
+    object: "model",
+    owned_by: "provider",
+    display_name: `Model ${index}`,
+  }));
+  const startedAt = Date.now();
+  do {
+    JSON.stringify({ object: "list", data: models });
+  } while (Date.now() - startedAt < BLOCK_MS);
+}
+
+test.after(() => {
+  fs.rmSync(CACHE_DATA_DIR, { recursive: true, force: true });
+});
+
+test("the /v1/models route wires Next after() as its response-flush-safe scheduler", () => {
+  const routeSource = fs.readFileSync(
+    path.join(REPO_ROOT, "src/app/api/v1/models/route.ts"),
+    "utf8"
+  );
+  const cacheSource = fs.readFileSync(
+    path.join(REPO_ROOT, "src/app/api/v1/models/catalogCache.ts"),
+    "utf8"
+  );
+  assert.match(routeSource, /import\s+\{\s*after\s*\}\s+from\s+["']next\/server["']/);
+  assert.match(routeSource, /scheduleBackgroundRefresh:\s*\(task\)\s*=>\s*after\(task\)/);
+  assert.match(cacheSource, /import\s+\{\s*after\s*\}\s+from\s+["']next\/server["']/);
+  assert.match(cacheSource, /function defaultBackgroundRefreshScheduler[\s\S]*?after\(task\)/);
+});
+
+test("an external client receives the stale body before synchronous refresh finishes blocking", async (t) => {
+  catalogCache.__resetCatalogBuilderRunsForTest();
+  const socketDir = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-swr-http-8728-"));
+  const socketPath = path.join(socketDir, "catalog.sock");
+
+  let buildCount = 0;
+  let responseFinishedAt = 0;
+  let refreshStartedAt = 0;
+  let refreshFinishedAt = 0;
+  let scheduledCount = 0;
+
+  const server = http.createServer(async (incoming, outgoing) => {
+    const url = `http://127.0.0.1${incoming.url || "/"}`;
+    const response = await catalogCache.resolveCachedCatalogResponse(
+      new Request(url),
+      { corsHeaders: {}, diagnosticHeaders: {} },
+      async () => {
+        buildCount++;
+        if (buildCount > 1) {
+          refreshStartedAt = Date.now();
+          productionShapedSynchronousRefresh();
+          refreshFinishedAt = Date.now();
+        }
+        return {
+          body: buildCount > 1 ? "new" : "old",
+          headers: { "content-type": "text/plain" },
+          status: 200,
+          cacheTTL: 60_000,
+        };
+      },
+      {
+        getStaleWhileRevalidateMs: () => Number.POSITIVE_INFINITY,
+        scheduleBackgroundRefresh: (task) => {
+          scheduledCount++;
+          outgoing.once("finish", () => {
+            responseFinishedAt = Date.now();
+            setImmediate(() => {
+              void task();
+            });
+          });
+        },
+      }
+    );
+
+    outgoing.writeHead(response.status, Object.fromEntries(response.headers.entries()));
+    outgoing.end(await response.text());
+  });
+
+  try {
+    await listen(server, socketPath);
+  } catch (error) {
+    if ((error as NodeJS.ErrnoException).code === "EPERM") {
+      t.skip("sandbox does not permit opening HTTP listener sockets");
+      fs.rmSync(socketDir, { recursive: true, force: true });
+      return;
+    }
+    throw error;
+  }
+  try {
+    assert.equal((await fetchFromExternalClient(socketPath)).body, "old");
+    catalogCache.__expireCatalogCacheForTest();
+
+    const stale = await fetchFromExternalClient(socketPath);
+    await catalogCache.__flushCatalogBackgroundRefreshForTest();
+
+    assert.equal(stale.body, "old");
+    assert.equal(scheduledCount, 1);
+    assert.ok(refreshStartedAt >= responseFinishedAt, "refresh must start after response finish");
+    assert.ok(
+      stale.receivedAt < refreshFinishedAt,
+      `external client received stale body at ${stale.receivedAt}, after refresh finished at ${refreshFinishedAt}`
+    );
+    assert.ok(
+      refreshFinishedAt - refreshStartedAt >= BLOCK_MS,
+      "refresh did not exercise the synchronous blocking window"
+    );
+  } finally {
+    await close(server);
+    fs.rmSync(socketDir, { recursive: true, force: true });
+    catalogCache.__resetCatalogBuilderRunsForTest();
+  }
+});
diff --git a/tests/unit/db-synced-model-catalog-invalidation-8728.test.ts b/tests/unit/db-synced-model-catalog-invalidation-8728.test.ts
new file mode 100644
index 0000000000..f013d530ff
--- /dev/null
+++ b/tests/unit/db-synced-model-catalog-invalidation-8728.test.ts
@@ -0,0 +1,166 @@
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import test from "node:test";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-db-model-cache-8728-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+process.env.DISABLE_SQLITE_AUTO_BACKUP = "true";
+
+const core = await import("../../src/lib/db/core.ts");
+const models = await import("../../src/lib/db/models.ts");
+const readCache = await import("../../src/lib/db/readCache.ts");
+
+function resetStorage() {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+}
+
+function catalogVersion() {
+  return readCache.getModelCatalogCacheVersion();
+}
+
+function totalChanges() {
+  return Number(
+    (
+      core.getDbInstance().prepare("SELECT total_changes() AS count").get() as {
+        count: number;
+      }
+    ).count
+  );
+}
+
+function seedSynced(providerId: string, connectionId: string, value: unknown) {
+  core
+    .getDbInstance()
+    .prepare("INSERT INTO key_value (namespace, key, value) VALUES ('syncedAvailableModels', ?, ?)")
+    .run(`${providerId}:${connectionId}`, JSON.stringify(value));
+}
+
+test.beforeEach(() => {
+  resetStorage();
+});
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+test("replace invalidates only for canonical persisted changes", async () => {
+  const initialVersion = catalogVersion();
+
+  await models.replaceSyncedAvailableModelsForConnection("openai", "a", [
+    {
+      id: "gpt-b",
+      name: " GPT B ",
+      source: "ignored",
+      supportedEndpoints: ["responses", "chat", "chat"],
+    },
+    { id: "gpt-a", name: "GPT A" },
+  ]);
+  assert.equal(catalogVersion(), initialVersion + 1);
+
+  const beforeIdenticalChanges = totalChanges();
+  const beforeIdenticalVersion = catalogVersion();
+  await models.replaceSyncedAvailableModelsForConnection("openai", "a", [
+    {
+      id: "gpt-b",
+      name: "GPT B",
+      source: "imported",
+      supportedEndpoints: ["chat", "responses"],
+    },
+    { id: "gpt-a", name: "GPT A", source: "imported" },
+  ]);
+  assert.equal(totalChanges(), beforeIdenticalChanges, "canonical equality must skip the DB write");
+  assert.equal(catalogVersion(), beforeIdenticalVersion, "canonical equality must not invalidate");
+
+  await models.replaceSyncedAvailableModelsForConnection("openai", "a", [
+    { id: "gpt-a", name: "GPT A" },
+    { id: "gpt-b", name: "GPT B", supportedEndpoints: ["chat", "responses"] },
+  ]);
+  assert.equal(catalogVersion(), beforeIdenticalVersion + 1, "ordering changes are persisted");
+
+  await models.replaceSyncedAvailableModelsForConnection("openai", "a", [
+    { id: "gpt-a", name: "GPT A renamed" },
+    { id: "gpt-b", name: "GPT B", supportedEndpoints: ["chat", "responses"] },
+  ]);
+  assert.equal(catalogVersion(), beforeIdenticalVersion + 2, "content changes are persisted");
+});
+
+test("replace handles empty and deleted-model normalization without phantom writes", async () => {
+  const startVersion = catalogVersion();
+  const startChanges = totalChanges();
+
+  await models.replaceSyncedAvailableModelsForConnection("openai", "absent", []);
+  assert.equal(totalChanges(), startChanges, "absent-to-empty replacement must be a no-op");
+  assert.equal(catalogVersion(), startVersion);
+
+  models.mergeModelCompatOverride("openai", "trashed", {
+    isDeleted: true,
+    isHidden: true,
+  });
+
+  const beforeDeletedAbsent = totalChanges();
+  const beforeDeletedVersion = catalogVersion();
+  await models.replaceSyncedAvailableModelsForConnection("openai", "absent", [
+    { id: "trashed", name: "Trashed" },
+  ]);
+  assert.equal(totalChanges(), beforeDeletedAbsent, "filtered deleted models must stay absent");
+  assert.equal(catalogVersion(), beforeDeletedVersion);
+
+  seedSynced("openai", "present", [{ id: "existing", name: "Existing" }]);
+  const beforeDeleteVersion = catalogVersion();
+  await models.replaceSyncedAvailableModelsForConnection("openai", "present", []);
+  assert.equal(catalogVersion(), beforeDeleteVersion + 1, "present-to-empty must invalidate");
+  assert.deepEqual(await models.getSyncedAvailableModelsForConnection("openai", "present"), []);
+});
+
+test("remove and connection/provider deletes invalidate only when rows actually change", async () => {
+  let version = catalogVersion();
+  assert.equal(await models.removeSyncedAvailableModel("openai", "missing"), false);
+  assert.equal(catalogVersion(), version);
+
+  seedSynced("openai", "a", [
+    { id: "gpt-a", name: "GPT A" },
+    { id: "gpt-b", name: "GPT B" },
+  ]);
+  assert.equal(await models.removeSyncedAvailableModel("openai", "gpt-a"), true);
+  assert.equal(catalogVersion(), ++version);
+  assert.equal(await models.removeSyncedAvailableModel("openai", "gpt-a"), false);
+  assert.equal(catalogVersion(), version);
+
+  await models.deleteSyncedAvailableModelsForConnection("openai", "missing");
+  assert.equal(catalogVersion(), version);
+  await models.deleteSyncedAvailableModelsForConnection("openai", "a");
+  assert.equal(catalogVersion(), ++version);
+
+  assert.equal(await models.deleteSyncedAvailableModelsForProvider("openai"), 0);
+  assert.equal(catalogVersion(), version);
+  seedSynced("openai", "b", [{ id: "gpt-b", name: "GPT B" }]);
+  seedSynced("openai", "c", [{ id: "gpt-c", name: "GPT C" }]);
+  assert.equal(await models.deleteSyncedAvailableModelsForProvider("openai"), 2);
+  assert.equal(catalogVersion(), ++version);
+});
+
+test("prune uses affected rows and the delegated provider delete invalidates exactly once", async () => {
+  seedSynced("openai", "keep", [{ id: "gpt-a", name: "GPT A" }]);
+  seedSynced("openai", "stale", [{ id: "gpt-b", name: "GPT B" }]);
+  let version = catalogVersion();
+
+  assert.equal(
+    await models.pruneStaleSyncedAvailableModelsForProvider("openai", ["keep", "stale"]),
+    0
+  );
+  assert.equal(catalogVersion(), version);
+
+  assert.equal(await models.pruneStaleSyncedAvailableModelsForProvider("openai", ["keep"]), 1);
+  assert.equal(catalogVersion(), ++version);
+
+  assert.equal(await models.pruneStaleSyncedAvailableModelsForProvider("openai", []), 1);
+  assert.equal(catalogVersion(), ++version, "delegated provider delete must invalidate once");
+
+  assert.equal(await models.pruneStaleSyncedAvailableModelsForProvider("openai", []), 0);
+  assert.equal(catalogVersion(), version);
+});
diff --git a/tests/unit/model-catalog-cache-swr-8728.test.ts b/tests/unit/model-catalog-cache-swr-8728.test.ts
new file mode 100644
index 0000000000..ffef72a217
--- /dev/null
+++ b/tests/unit/model-catalog-cache-swr-8728.test.ts
@@ -0,0 +1,203 @@
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import test from "node:test";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-catalog-cache-8728-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const readCache = await import("../../src/lib/db/readCache.ts");
+const catalogCache = await import("../../src/app/api/v1/models/catalogCache.ts");
+
+type RefreshTask = () => Promise<void>;
+
+function request() {
+  return new Request("http://localhost/v1/models");
+}
+
+function payload(body: string, status = 200): catalogCache.CatalogPayload {
+  return {
+    body,
+    headers: { "content-type": "application/json" },
+    status,
+    cacheTTL: 60_000,
+  };
+}
+
+function createPolicyQueue() {
+  const tasks: RefreshTask[] = [];
+  return {
+    policy: {
+      getStaleWhileRevalidateMs: () => Number.POSITIVE_INFINITY,
+      scheduleBackgroundRefresh: (task: RefreshTask) => {
+        tasks.push(task);
+      },
+    },
+    tasks,
+  };
+}
+
+async function resolve(
+  build: (request: Request) => Promise<catalogCache.CatalogPayload>,
+  policy = createPolicyQueue().policy
+) {
+  return catalogCache.resolveCachedCatalogResponse(
+    request(),
+    { corsHeaders: {}, diagnosticHeaders: {} },
+    build,
+    policy
+  );
+}
+
+test.beforeEach(() => {
+  catalogCache.__resetCatalogBuilderRunsForTest();
+});
+
+test.after(() => {
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+test("production SWR policy is unbounded and reset restores the default accessor", () => {
+  assert.equal(catalogCache.CATALOG_STALE_WHILE_REVALIDATE_MS, Number.POSITIVE_INFINITY);
+  assert.equal(catalogCache.getCatalogStaleWhileRevalidateMs(), Number.POSITIVE_INFINITY);
+
+  catalogCache.__setCatalogStaleWhileRevalidateAccessorForTest(() => 0);
+  assert.equal(catalogCache.getCatalogStaleWhileRevalidateMs(), 0);
+
+  catalogCache.__resetCatalogBuilderRunsForTest();
+  assert.equal(catalogCache.getCatalogStaleWhileRevalidateMs(), Number.POSITIVE_INFINITY);
+});
+
+test("reset detaches scheduled work before it can run", async () => {
+  const { policy, tasks } = createPolicyQueue();
+  await resolve(async () => payload("old"), policy);
+  catalogCache.__expireCatalogCacheForTest();
+  await resolve(async () => payload("detached"), policy);
+  assert.equal(tasks.length, 1);
+
+  catalogCache.__resetCatalogBuilderRunsForTest();
+  await tasks[0]();
+
+  assert.equal(catalogCache.__getCatalogBuilderRunsForTest(), 0);
+});
+
+test("ordinary TTL expiry serves the last success indefinitely and schedules one refresh per key", async () => {
+  const { policy, tasks } = createPolicyQueue();
+  const initial = await resolve(async () => payload("old"), policy);
+  assert.equal(await initial.text(), "old");
+  catalogCache.__expireCatalogCacheForTest(7 * 24 * 60 * 60 * 1000);
+
+  const staleResponses = await Promise.all(
+    Array.from({ length: 5 }, () => resolve(async () => payload("new"), policy))
+  );
+
+  assert.deepEqual(
+    await Promise.all(staleResponses.map((response) => response.text())),
+    Array(5).fill("old")
+  );
+  assert.equal(tasks.length, 1, "concurrent stale reads must schedule exactly one refresh");
+  assert.equal(catalogCache.__getCatalogBuilderRunsForTest(), 1);
+
+  await tasks[0]();
+
+  const refreshed = await resolve(async () => payload("unexpected"), policy);
+  assert.equal(await refreshed.text(), "new");
+  assert.equal(catalogCache.__getCatalogBuilderRunsForTest(), 2);
+});
+
+test("unsuccessful cold payloads are returned but never cached", async () => {
+  const first = await resolve(async () => payload("temporary failure", 503));
+  assert.equal(first.status, 503);
+  assert.equal(await first.text(), "temporary failure");
+
+  const second = await resolve(async () => payload("recovered"));
+  assert.equal(second.status, 200);
+  assert.equal(await second.text(), "recovered");
+  assert.equal(catalogCache.__getCatalogBuilderRunsForTest(), 2);
+});
+
+test("failed background refresh retains the prior successful snapshot and permits retry", async (t) => {
+  t.mock.method(console, "error", () => {});
+  const { policy, tasks } = createPolicyQueue();
+  assert.equal(await (await resolve(async () => payload("old"), policy)).text(), "old");
+  catalogCache.__expireCatalogCacheForTest();
+
+  assert.equal(
+    await (
+      await resolve(async () => {
+        throw new Error("temporary failure");
+      }, policy)
+    ).text(),
+    "old"
+  );
+  await tasks.shift()!();
+
+  assert.equal(
+    await (await resolve(async () => payload("temporary failure", 503), policy)).text(),
+    "old"
+  );
+  assert.equal(tasks.length, 1, "a failed refresh must release single-flight state for retry");
+  await tasks.shift()!();
+
+  assert.equal(await (await resolve(async () => payload("new"), policy)).text(), "old");
+  assert.equal(tasks.length, 1, "an unsuccessful payload must also permit another refresh");
+  await tasks.shift()!();
+
+  assert.equal(await (await resolve(async () => payload("unused"), policy)).text(), "new");
+});
+
+test("hard invalidation drops snapshots, detaches old work, and guards old-generation writeback", async () => {
+  let resolveOld!: (value: catalogCache.CatalogPayload) => void;
+  const oldPayload = new Promise<catalogCache.CatalogPayload>((resolvePromise) => {
+    resolveOld = resolvePromise;
+  });
+  let currentBuildStarted = false;
+  let resolveCurrent!: (value: catalogCache.CatalogPayload) => void;
+  const currentPayload = new Promise<catalogCache.CatalogPayload>((resolvePromise) => {
+    resolveCurrent = resolvePromise;
+  });
+
+  const oldRequest = resolve(async () => oldPayload);
+  await Promise.resolve();
+
+  readCache.invalidateModelCatalogCache();
+  const currentRequest = resolve(async () => {
+    currentBuildStarted = true;
+    return currentPayload;
+  });
+  await Promise.resolve();
+
+  assert.equal(currentBuildStarted, true, "the first post-write read must start a current build");
+
+  resolveCurrent(payload("current"));
+  assert.equal(await (await currentRequest).text(), "current");
+
+  resolveOld(payload("old"));
+  assert.equal(await (await oldRequest).text(), "old");
+
+  const cached = await resolve(async () => payload("unexpected"));
+  assert.equal(await cached.text(), "current", "old completion must not overwrite current cache");
+  assert.equal(catalogCache.__getCatalogBuilderRunsForTest(), 2);
+});
+
+test("hard invalidation clears a completed snapshot and makes the next read block", async () => {
+  assert.equal(await (await resolve(async () => payload("old"))).text(), "old");
+  readCache.invalidateModelCatalogCache();
+
+  let resolveCurrent!: (value: catalogCache.CatalogPayload) => void;
+  const currentPayload = new Promise<catalogCache.CatalogPayload>((resolvePromise) => {
+    resolveCurrent = resolvePromise;
+  });
+  let settled = false;
+  const next = resolve(async () => currentPayload).then((response) => {
+    settled = true;
+    return response;
+  });
+
+  await Promise.resolve();
+  assert.equal(settled, false, "post-write reads may block and must not serve the old snapshot");
+
+  resolveCurrent(payload("current"));
+  assert.equal(await (await next).text(), "current");
+});
diff --git a/tests/unit/model-catalog-policy-invalidation-8728.test.ts b/tests/unit/model-catalog-policy-invalidation-8728.test.ts
new file mode 100644
index 0000000000..4c9c7e2744
--- /dev/null
+++ b/tests/unit/model-catalog-policy-invalidation-8728.test.ts
@@ -0,0 +1,178 @@
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import test from "node:test";
+
+const TEST_DATA_DIR = fs.mkdtempSync(
+  path.join(os.tmpdir(), "omniroute-model-catalog-policy-8728-"),
+);
+process.env.DATA_DIR = TEST_DATA_DIR;
+process.env.DISABLE_SQLITE_AUTO_BACKUP = "true";
+process.env.API_KEY_SECRET = process.env.API_KEY_SECRET || "model-catalog-policy-invalidation-8728";
+
+const core = await import("../../src/lib/db/core.ts");
+const readCache = await import("../../src/lib/db/readCache.ts");
+const apiKeys = await import("../../src/lib/db/apiKeys.ts");
+const apiKeyGroups = await import("../../src/lib/db/apiKeyGroups.ts");
+const models = await import("../../src/lib/db/models.ts");
+const quotaPools = await import("../../src/lib/db/quotaPools.ts");
+const quotaGroups = await import("../../src/lib/db/quotaGroups.ts");
+
+async function resetStorage() {
+  core.resetDbInstance();
+  apiKeys.resetApiKeyState();
+
+  for (let attempt = 0; attempt < 10; attempt++) {
+    try {
+      if (fs.existsSync(TEST_DATA_DIR)) {
+        fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+      }
+      break;
+    } catch (error: unknown) {
+      const err = error as NodeJS.ErrnoException;
+      if ((err?.code === "EBUSY" || err?.code === "EPERM") && attempt < 9) {
+        await new Promise((resolve) => setTimeout(resolve, 50 * (attempt + 1)));
+      } else {
+        throw error;
+      }
+    }
+  }
+
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+}
+
+function catalogVersion() {
+  return readCache.getModelCatalogCacheVersion();
+}
+
+test.beforeEach(async () => {
+  await resetStorage();
+});
+
+test.after(() => {
+  core.resetDbInstance();
+  apiKeys.resetApiKeyState();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+test("updateApiKeyPermissions increments only on catalog-affecting fields", async () => {
+  const created = await apiKeys.createApiKey("Cache Policy Key", "machine-cpi-1");
+  let version = catalogVersion();
+
+  assert.equal(await apiKeys.updateApiKeyPermissions(created.id, { isActive: false }), true);
+  assert.equal(catalogVersion(), version, "isActive does not invalidate model-catalog cache");
+
+  assert.equal(await apiKeys.updateApiKeyPermissions(created.id, {}), false);
+  assert.equal(catalogVersion(), version, "no-op update does not invalidate model-catalog cache");
+
+  await apiKeys.updateApiKeyPermissions(created.id, { allowedModels: ["openai/*"] });
+  assert.equal(catalogVersion(), ++version);
+
+  await apiKeys.updateApiKeyPermissions(created.id, { blockedModels: ["openai/sandbox/*"] });
+  assert.equal(catalogVersion(), ++version);
+
+  await apiKeys.updateApiKeyPermissions(created.id, { allowedQuotas: ["q-1", "q-2"] });
+  assert.equal(catalogVersion(), ++version);
+
+  await apiKeys.updateApiKeyPermissions(created.id, { disableNonPublicModels: true });
+  assert.equal(catalogVersion(), ++version);
+});
+
+test("isModelAllowedForKey cache recomputes when group permissions change", async () => {
+  const key = await apiKeys.createApiKey("Group Visibility Key", "machine-cpi-2");
+  const modelId = "openai/gpt-4o-mini";
+  await apiKeys.updateApiKeyPermissions(key.id, { allowedModels: ["openai/*"] });
+
+  assert.equal(await apiKeys.isModelAllowedForKey(key.key, modelId), true);
+
+  const group = apiKeyGroups.createKeyGroup("Model deny", "denies openai");
+  apiKeyGroups.addGroupPermission(group.id, "openai/*", "deny");
+  assert.equal(apiKeyGroups.addKeyToGroup(key.id, group.id), true);
+
+  assert.equal(await apiKeys.isModelAllowedForKey(key.key, modelId), false);
+  assert.ok(catalogVersion() > 0, "group visibility change increments model catalog generation");
+});
+
+test("isModelAllowedForKey cache recomputes after custom model visibility changes", async () => {
+  const key = await apiKeys.createApiKey("Custom Visibility Key", "machine-cpi-3");
+  await apiKeys.updateApiKeyPermissions(key.id, {
+    allowedModels: ["openai/*"],
+    disableNonPublicModels: true,
+  });
+
+  const modelId = "openai/catalog-cache-repro";
+  await models.addCustomModel(
+    "openai",
+    "catalog-cache-repro",
+    "Catalog cache repro",
+    "manual",
+    "chat-completions",
+    ["chat"],
+  );
+
+  assert.equal(await apiKeys.isModelAllowedForKey(key.key, modelId), true);
+
+  models.setModelIsHidden("openai", "catalog-cache-repro", true);
+  assert.equal(await apiKeys.isModelAllowedForKey(key.key, modelId), false);
+});
+
+test("API-key group membership only invalidates model catalog on real membership mutations", async () => {
+  const key = await apiKeys.createApiKey("Group Membership Key", "machine-cpi-5");
+  const group = apiKeyGroups.createKeyGroup("Model deny", "denies openai");
+  let version = catalogVersion();
+
+  assert.equal(apiKeyGroups.addKeyToGroup(key.id, group.id), true);
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  assert.equal(apiKeyGroups.addKeyToGroup(key.id, group.id), true);
+  assert.equal(catalogVersion(), version);
+
+  assert.equal(apiKeyGroups.removeKeyFromGroup(key.id, group.id), true);
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  assert.equal(apiKeyGroups.removeKeyFromGroup(key.id, group.id), false);
+  assert.equal(catalogVersion(), version);
+});
+
+test("quota pools and quota-group renames signal model-catalog invalidation as expected", async () => {
+  let version = catalogVersion();
+  const pool = quotaPools.createPool({
+    connectionId: "conn-quota",
+    name: "Quota Pool",
+    groupId: "group-demo",
+  });
+  assert.equal(catalogVersion(), version + 1);
+
+  const group = quotaGroups.createGroup("Quota Group");
+  assert.equal(catalogVersion(), version + 1, "creating quota groups does not invalidate catalog");
+
+  version = catalogVersion();
+  const renamed = quotaGroups.renameGroup(group.id, "Renamed Quota Group");
+  assert.equal(renamed, true);
+  assert.equal(catalogVersion(), version + 1, "quota-group rename invalidates catalog");
+
+  version = catalogVersion();
+  assert.notEqual(quotaPools.updatePool(pool.id, { name: "Quota Pool Updated" }), null);
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  assert.equal(quotaPools.deletePool(pool.id), true);
+  assert.equal(catalogVersion(), version + 1);
+});
+
+test("deletePool clears primed key metadata after allowed_quotas rewrite", async () => {
+  const pool = quotaPools.createPool({ connectionId: "conn-meta", name: "Meta Pool" });
+  const key = await apiKeys.createApiKey("Pool Metadata Key", "machine-cpi-4");
+
+  await apiKeys.updateApiKeyPermissions(key.id, { allowedQuotas: [pool.id] });
+  const before = await apiKeys.getApiKeyMetadata(key.key);
+  assert.deepEqual(before?.allowedQuotas, [pool.id]);
+
+  assert.equal(quotaPools.deletePool(pool.id), true);
+
+  const after = await apiKeys.getApiKeyMetadata(key.key);
+  assert.deepEqual(after?.allowedQuotas, [], "allowed_quotas cache must reflect direct rewrite");
+});
diff --git a/tests/unit/model-catalog-source-invalidation-8728.test.ts b/tests/unit/model-catalog-source-invalidation-8728.test.ts
new file mode 100644
index 0000000000..50dfa86eff
--- /dev/null
+++ b/tests/unit/model-catalog-source-invalidation-8728.test.ts
@@ -0,0 +1,214 @@
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import test from "node:test";
+
+const TEST_DATA_DIR = fs.mkdtempSync(
+  path.join(os.tmpdir(), "omniroute-model-catalog-sources-8728-"),
+);
+process.env.DATA_DIR = TEST_DATA_DIR;
+process.env.DISABLE_SQLITE_AUTO_BACKUP = "true";
+
+const core = await import("../../src/lib/db/core.ts");
+const models = await import("../../src/lib/db/models.ts");
+const aliases = await import("../../src/lib/db/models/aliases.ts");
+const compat = await import("../../src/lib/db/models/compat.ts");
+const ccAliases = await import("../../src/lib/db/ccDiscoveryAliases.ts");
+const featureFlags = await import("../../src/lib/db/featureFlags.ts");
+const readCache = await import("../../src/lib/db/readCache.ts");
+const openRouterCatalog = await import("../../src/lib/catalog/openrouterCatalog.ts");
+
+function resetStorage() {
+  core.resetDbInstance();
+  if (fs.existsSync(TEST_DATA_DIR)) {
+    fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+  }
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+}
+
+function catalogVersion() {
+  return readCache.getModelCatalogCacheVersion();
+}
+
+const REAL_FETCH = globalThis.fetch;
+
+function installMockOpenRouterFetch(payload: { data: Array<Record<string, unknown>> }): void {
+  globalThis.fetch = (async () =>
+    new Response(JSON.stringify(payload), {
+      status: 200,
+      headers: { "content-type": "application/json" },
+    })) as typeof fetch;
+}
+
+function installFailingOpenRouterFetch(): void {
+  globalThis.fetch = (async () => {
+    throw new Error("simulated openrouter failure");
+  }) as typeof fetch;
+}
+
+function restoreRealFetch(): void {
+  globalThis.fetch = REAL_FETCH;
+}
+
+test.beforeEach(() => {
+  resetStorage();
+});
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+  restoreRealFetch();
+});
+
+test("custom-model source writes invalidate model-catalog cache version; no-op writes do not", async () => {
+  let version = catalogVersion();
+
+  await models.addCustomModel("openai", "manual-one");
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  const duplicate = await models.addCustomModel("openai", "manual-one");
+  assert.equal(duplicate.id, "manual-one");
+  assert.equal(catalogVersion(), version);
+
+  await models.replaceCustomModels("openai", [
+    { id: "manual-one", source: "manual", apiFormat: "chat-completions" },
+    { id: "imported-one", source: "auto-sync", apiFormat: "chat-completions" },
+  ]);
+  version = version + 1;
+  assert.equal(catalogVersion(), version);
+
+  const removedIds = await models.deleteImportedCustomModels("openai");
+  assert.deepEqual(removedIds, ["imported-one"]);
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  const removedExisting = await models.removeCustomModel("openai", "manual-one");
+  assert.equal(removedExisting, true);
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  const removedMissing = await models.removeCustomModel("openai", "missing");
+  assert.equal(removedMissing, false);
+  assert.equal(catalogVersion(), version);
+
+  const updatedMissing = await models.updateCustomModel("openai", "missing", {
+    modelName: "Missing",
+  });
+  assert.equal(updatedMissing, null);
+  assert.equal(catalogVersion(), version);
+
+  const noImported = await models.deleteImportedCustomModels("openai");
+  assert.deepEqual(noImported, []);
+  assert.equal(catalogVersion(), version);
+
+  await models.addCustomModel("openai", "manual-two", "manual two");
+  version = catalogVersion();
+  const updateResult = await models.updateCustomModel("openai", "manual-two", {
+    modelName: "Manual Two",
+  });
+  assert.notEqual(updateResult, null);
+  assert.equal(catalogVersion(), version + 1);
+
+  const noTarget = await models.updateCustomModel("openai", "missing", { modelName: "Missing" });
+  assert.equal(noTarget, null);
+  assert.equal(catalogVersion(), version + 1);
+});
+
+test("model alias and compat writes invalidate model-catalog cache version", async () => {
+  let version = catalogVersion();
+
+  await aliases.setModelAlias("alias-alpha", "openai/manual-one");
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  await aliases.deleteModelAlias("alias-alpha");
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  compat.writeCompatList("openai", [
+    {
+      id: "manual-two",
+      normalizeToolCallId: true,
+    },
+  ]);
+  assert.equal(catalogVersion(), version + 1);
+});
+
+test("Claude Code discovery alias setters invalidate on both write and inherit/delete", () => {
+  let version = catalogVersion();
+
+  ccAliases.setCcAliasProviderSetting("openai", "on");
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  ccAliases.setCcAliasProviderSetting("openai", null);
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  ccAliases.setCcAliasModelSetting("openai", "gpt-4", "on");
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  ccAliases.setCcAliasModelSetting("openai", "gpt-4", null);
+  assert.equal(catalogVersion(), version + 1);
+});
+
+test("feature flag writes invalidate catalog version only for catalog-relevant overrides", async () => {
+  const unrelatedBefore = catalogVersion();
+  featureFlags.setFeatureFlagOverride("ARENA_ELO_SYNC_ENABLED", "true");
+  assert.equal(catalogVersion(), unrelatedBefore);
+
+  let version = catalogVersion();
+  featureFlags.setFeatureFlagOverride("MODEL_CATALOG_INCLUDE_NAMES", "false");
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  featureFlags.setFeatureFlagOverride("MODELS_CATALOG_PREFIX_MODE", "alias");
+  assert.equal(catalogVersion(), version + 1);
+
+  version = catalogVersion();
+  featureFlags.setFeatureFlagOverride("EXPOSE_CC_DISCOVERY_ALIASES", "true");
+  assert.equal(catalogVersion(), version + 1);
+
+  const relevantKeyBeforeRemove = catalogVersion();
+  featureFlags.removeFeatureFlagOverride("MODEL_CATALOG_INCLUDE_NAMES");
+  assert.equal(catalogVersion(), relevantKeyBeforeRemove + 1);
+
+  featureFlags.setFeatureFlagOverride("MODELS_CATALOG_PREFIX_MODE", "dual");
+  const irrelevantClearVersion = catalogVersion();
+  featureFlags.setFeatureFlagOverride("ARENA_ELO_SYNC_ENABLED", "true");
+  featureFlags.clearAllFeatureFlagOverrides();
+  assert.equal(catalogVersion(), irrelevantClearVersion + 1);
+
+  const clearNoRelevantBefore = catalogVersion();
+  featureFlags.clearAllFeatureFlagOverrides();
+  assert.equal(catalogVersion(), clearNoRelevantBefore);
+});
+
+test("refreshOpenRouterCatalog invalidates only on success", async () => {
+  installMockOpenRouterFetch({ data: [{ id: "openrouter/fake", source: "test" }] });
+  try {
+    const beforeGet = catalogVersion();
+    await openRouterCatalog.getOpenRouterCatalog();
+    assert.equal(
+      catalogVersion(),
+      beforeGet,
+      "ordinary get should not invalidate the model-catalog cache",
+    );
+
+    const beforeRefreshSuccess = catalogVersion();
+    const success = await openRouterCatalog.refreshOpenRouterCatalog();
+    assert.equal(success.ok, true);
+    assert.equal(catalogVersion(), beforeRefreshSuccess + 1);
+
+    installFailingOpenRouterFetch();
+    const beforeRefreshFailure = catalogVersion();
+    const failed = await openRouterCatalog.refreshOpenRouterCatalog();
+    assert.equal(failed.ok, false);
+    assert.equal(catalogVersion(), beforeRefreshFailure, "failed refresh should not invalidate");
+  } finally {
+    restoreRealFetch();
+  }
+});
diff --git a/tests/unit/quota-exclusive-catalog-short-circuit.test.ts b/tests/unit/quota-exclusive-catalog-short-circuit.test.ts
index c3710a1cff..f6b786d643 100644
--- a/tests/unit/quota-exclusive-catalog-short-circuit.test.ts
+++ b/tests/unit/quota-exclusive-catalog-short-circuit.test.ts
@@ -134,9 +134,8 @@ await test("chave quota-exclusive não constrói o catálogo completo", async (t
     process.env.EXPOSE_CC_DISCOVERY_ALIASES = "1";
     // A chave do cache é `prefix|isCodex|apiKey|configuredOnly` — um query param
     // qualquer NÃO a invalida, então a resposta do subteste anterior seria servida.
-    v1ModelsCatalog.__expireCatalogCacheForTest(
-      v1ModelsCatalog.CATALOG_STALE_WHILE_REVALIDATE_MS + 1000
-    );
+    v1ModelsCatalog.__setCatalogStaleWhileRevalidateMsForTest(0);
+    v1ModelsCatalog.__expireCatalogCacheForTest(1);
     try {
       const res = await v1ModelsCatalog.getUnifiedModelsResponse(
         new Request("http://localhost/api/v1/models", {
@@ -152,6 +151,9 @@ await test("chave quota-exclusive não constrói o catálogo completo", async (t
           `ids=${JSON.stringify(body.data.map((m) => m.id).slice(0, 6))}`
       );
     } finally {
+      v1ModelsCatalog.__setCatalogStaleWhileRevalidateMsForTest(
+        v1ModelsCatalog.CATALOG_STALE_WHILE_REVALIDATE_MS
+      );
       if (prev === undefined) delete process.env.EXPOSE_CC_DISCOVERY_ALIASES;
       else process.env.EXPOSE_CC_DISCOVERY_ALIASES = prev;
     }
diff --git a/tests/unit/v1-models-discovery-conformance.test.ts b/tests/unit/v1-models-discovery-conformance.test.ts
index e1ab778003..9941d18ca5 100644
--- a/tests/unit/v1-models-discovery-conformance.test.ts
+++ b/tests/unit/v1-models-discovery-conformance.test.ts
@@ -108,27 +108,29 @@ test("3. stale-first: an expired 200 entry within the staleness window is served
   );
 });
 
-test("4. beyond the staleness window, the response waits for a fresh build again", async () => {
+test("4. an ordinary TTL expiry remains stale-first regardless of snapshot age", async () => {
   const makeRequest = () => new Request("http://localhost/v1/models");
 
   const res1 = await v1ModelsCatalog.getUnifiedModelsResponse(makeRequest());
   assert.equal(res1.status, 200);
+  const body1 = await res1.text();
   const runsAfterFirst = v1ModelsCatalog.__getCatalogBuilderRunsForTest();
   assert.equal(runsAfterFirst, 1);
 
-  // Push the entry's age past CATALOG_STALE_WHILE_REVALIDATE_MS.
-  v1ModelsCatalog.__expireCatalogCacheForTest(
-    v1ModelsCatalog.CATALOG_STALE_WHILE_REVALIDATE_MS + 5_000
-  );
+  // Age well past the historical 30-second bound. Ordinary expiry must not turn a
+  // refresh failure into a client-visible cold-build wait.
+  v1ModelsCatalog.__expireCatalogCacheForTest(24 * 60 * 60 * 1000);
 
   const res2 = await v1ModelsCatalog.getUnifiedModelsResponse(makeRequest());
   assert.equal(res2.status, 200);
+  assert.equal(await res2.text(), body1);
   assert.equal(
     v1ModelsCatalog.__getCatalogBuilderRunsForTest(),
-    runsAfterFirst + 1,
-    "past the staleness window, the builder must run again BEFORE the response is returned " +
-      "(a refresh that keeps failing must not pin a stale catalog forever)"
+    runsAfterFirst,
+    "ordinary TTL expiry must return the last successful snapshot before refreshing"
   );
+  await v1ModelsCatalog.__flushCatalogBackgroundRefreshForTest();
+  assert.equal(v1ModelsCatalog.__getCatalogBuilderRunsForTest(), runsAfterFirst + 1);
 });
 
 test("5. a cached non-200 entry is never served as stale", async () => {