diff --git a/changelog.d/fixes/11089-chat-routing-synced-inventory.md b/changelog.d/fixes/11089-chat-routing-synced-inventory.md
new file mode 100644
index 0000000000..922b96a659
--- /dev/null
+++ b/changelog.d/fixes/11089-chat-routing-synced-inventory.md
@@ -0,0 +1 @@
+- **fix(resilience):** filter chat connection selection by each connection's *synced* model inventory on multi-host self-hosted providers (`ollama-local`, `lm-studio`, `vllm`, …), so a request for a model only one host advertises is pinned to that host instead of failing over onto a host that never had it ([#11089](https://github.com/diegosouzapw/OmniRoute/issues/11089))
diff --git a/config/quality/file-size-baseline.json b/config/quality/file-size-baseline.json
index 28accfeae5..0a3239ea7f 100644
--- a/config/quality/file-size-baseline.json
+++ b/config/quality/file-size-baseline.json
@@ -432,7 +432,8 @@
     "src/shared/components/analytics/charts.tsx": 1346,
     "src/shared/services/cliRuntime.ts": 1459,
     "src/sse/handlers/chat.ts": 2493,
-    "src/sse/services/auth.ts": 3260,
+    "src/sse/services/auth.ts": 3337,
+    "_rebaseline_2026_08_23_11186_synced_inventory_routing": "PR #11186 (pacocartones) own growth: src/sse/services/auth.ts 3260->3337 (+77, loadAdvertisedModelsForSelfHostedConnections + the modelNotAdvertised candidate-filter predicate — pins chat routing to the connection whose synced inventory actually advertises the model, fixing spurious model-not-found on multi-host self-hosted setups; at the existing credential-selection chokepoint, not extractable without splitting the selection flow). Covered by tests/unit/chat-routing-synced-inventory-11089.test.ts. Owner pre-authorized baseline bumps 2026-08-22.",
     "tests/unit/account-fallback-service.test.ts": 2044,
     "tests/unit/provider-validation-specialty.test.ts": 3880,
     "open-sse/executors/hyperagent.ts": 1334,
diff --git a/src/domain/connectionModelRules.ts b/src/domain/connectionModelRules.ts
index 316ade72d8..7831bbc84b 100644
--- a/src/domain/connectionModelRules.ts
+++ b/src/domain/connectionModelRules.ts
@@ -80,3 +80,26 @@ export function hasEligibleConnectionForModel(
     (connection) => !isModelExcludedByConnection(modelId, connection?.providerSpecificData)
   );
 }
+
+/**
+ * #11089: does this connection's *synced* inventory advertise the model?
+ *
+ * Unlike `excludedModels` (a manually maintained denylist) this reads the
+ * per-connection catalog written by model discovery, so a multi-host local
+ * provider never routes a model to a host that never had it. Ids are matched
+ * with the same candidate semantics as the denylist (provider prefix and the
+ * `[1m]` extended-context suffix are tolerated), but never as wildcard
+ * patterns — a synced id is a literal.
+ *
+ * Fails OPEN on an empty inventory: a host that has not been synced yet is
+ * "unknown", not "does not have it".
+ */
+export function isModelAdvertisedByConnection(
+  modelId: unknown,
+  advertisedModelIds: ReadonlySet<string> | null | undefined
+): boolean {
+  if (!advertisedModelIds || advertisedModelIds.size === 0) return true;
+  if (typeof modelId !== "string" || modelId.trim().length === 0) return true;
+
+  return getModelMatchCandidates(modelId).some((candidate) => advertisedModelIds.has(candidate));
+}
diff --git a/src/sse/services/auth.ts b/src/sse/services/auth.ts
index 35304a05e6..5d3d885178 100644
--- a/src/sse/services/auth.ts
+++ b/src/sse/services/auth.ts
@@ -106,8 +106,17 @@ import {
   resolveProviderId,
   NOAUTH_PROVIDERS,
   WEB_COOKIE_PROVIDERS,
+  isSelfHostedChatProvider,
 } from "@/shared/constants/providers";
-import { isModelExcludedByConnection } from "@/domain/connectionModelRules";
+import {
+  isModelExcludedByConnection,
+  isModelAdvertisedByConnection,
+} from "@/domain/connectionModelRules";
+import {
+  getSyncedAvailableModelsByConnection,
+  SYNCED_AVAILABLE_MODELS_MALFORMED,
+  type SyncedAvailableModelsByConnection,
+} from "@/lib/db/models";
 import { isFreeModel } from "@/shared/utils/freeModels";
 import {
   applySessionAffinityPin,
@@ -1160,6 +1169,54 @@ function materializeConnection(
   };
 }
 
+/**
+ * #11089: load the per-connection synced model inventory for self-hosted chat
+ * providers so connection selection can drop hosts that never advertised the
+ * requested model.
+ *
+ * Scoped to SELF_HOSTED_CHAT_PROVIDER_IDS: those are the providers where one
+ * provider id fans out to several independent hosts with genuinely different
+ * inventories. Hosted providers share one catalog per provider, so filtering
+ * there would only add a DB read.
+ *
+ * Returns an empty map (= no filtering) when there is no model to match, when
+ * no candidate is self-hosted, or when the persisted rows are malformed — a
+ * partial read must never silently shrink the pool.
+ */
+async function loadAdvertisedModelsForSelfHostedConnections(
+  connections: ProviderConnectionView[],
+  requestedModel: string | null
+): Promise<Map<string, Set<string>>> {
+  const advertised = new Map<string, Set<string>>();
+  if (!requestedModel) return advertised;
+
+  const selfHostedProviders = new Set(
+    connections
+      .map((c) => c.provider)
+      .filter((p): p is string => typeof p === "string" && isSelfHostedChatProvider(p))
+  );
+  if (selfHostedProviders.size === 0) return advertised;
+
+  await Promise.all(
+    [...selfHostedProviders].map(async (providerId) => {
+      let byConnection: SyncedAvailableModelsByConnection;
+      try {
+        byConnection = await getSyncedAvailableModelsByConnection(providerId);
+      } catch {
+        return;
+      }
+      // Malformed persisted rows: fail open for the whole provider.
+      if (byConnection[SYNCED_AVAILABLE_MODELS_MALFORMED]) return;
+      for (const [connectionId, models] of Object.entries(byConnection)) {
+        if (!Array.isArray(models) || models.length === 0) continue;
+        advertised.set(connectionId, new Set(models.map((m) => m.id)));
+      }
+    })
+  );
+
+  return advertised;
+}
+
 /**
  * Get provider credentials from localDb
  * Filters out unavailable accounts and returns the selected account based on strategy
@@ -1435,6 +1492,14 @@ export async function getProviderCredentials(
     let modelLockedCount = 0;
     let familyLockedCount = 0;
     const connectionFilterStatus = new Map<string, string>();
+    // #11089: multi-host self-hosted providers keep a per-connection synced
+    // inventory. Without it, a request can be routed to a host that never had
+    // the model, producing a spurious model-not-found instead of pinning to
+    // the host that does. Empty map = no inventory known = no filtering.
+    const advertisedModelsByConnection = await loadAdvertisedModelsForSelfHostedConnections(
+      connections,
+      requestedModel
+    );
     // Filter out unavailable accounts and excluded connection
     let availableConnections = connections.filter((c) => {
       if (excludedConnectionIds.has(c.id)) {
@@ -1445,6 +1510,13 @@ export async function getProviderCredentials(
         connectionFilterStatus.set(c.id, "modelExcluded");
         return false;
       }
+      if (
+        requestedModel &&
+        !isModelAdvertisedByConnection(requestedModel, advertisedModelsByConnection.get(c.id))
+      ) {
+        connectionFilterStatus.set(c.id, "modelNotAdvertised");
+        return false;
+      }
       if (!allowSuppressedConnections) {
         if (!allowRateLimitedConnections && isAccountUnavailable(c.rateLimitedUntil)) {
           connectionFilterStatus.set(c.id, "rateLimited");
@@ -1510,6 +1582,7 @@ export async function getProviderCredentials(
       const codexScopeLimited = status === "codexScopeLimited";
       const modelLocked = status === "modelLocked";
       const modelExcluded = status === "modelExcluded";
+      const modelNotAdvertised = status === "modelNotAdvertised";
       if (excluded || rateLimited) {
         log.debug(
           "AUTH",
@@ -1520,6 +1593,11 @@ export async function getProviderCredentials(
           "AUTH",
           `  → ${c.id?.slice(0, 8)} | excluded by per-account model rule for ${requestedModel}`
         );
+      } else if (modelNotAdvertised) {
+        log.debug(
+          "AUTH",
+          `  → ${c.id?.slice(0, 8)} | synced inventory does not advertise ${requestedModel}`
+        );
       } else if (terminalStatus) {
         log.debug(
           "AUTH",
diff --git a/tests/unit/chat-routing-synced-inventory-11089.test.ts b/tests/unit/chat-routing-synced-inventory-11089.test.ts
new file mode 100644
index 0000000000..441b14893b
--- /dev/null
+++ b/tests/unit/chat-routing-synced-inventory-11089.test.ts
@@ -0,0 +1,184 @@
+/**
+ * tests/unit/chat-routing-synced-inventory-11089.test.ts
+ *
+ * #11089 — Chat routing ignores per-connection model inventory on multi-host
+ * local providers.
+ *
+ * One self-hosted provider (`ollama-local`) with TWO connections pointing at
+ * different hosts and DISJOINT synced inventories:
+ *
+ *   studio (priority 1) → gemma3:4b, flux2-klein:9b
+ *   jetson (priority 2) → gemma3:4b
+ *
+ * `getProviderCredentials` only ever consulted the manual `excludedModels`
+ * denylist, never the synced inventory persisted per connection, so a request
+ * for `flux2-klein:9b` could land on jetson — a host that never had the model.
+ *
+ * Cases:
+ * 1. Model advertised by only one connection → the other is never selected.
+ * 2. Higher-priority host cooling → must NOT preemptively fall to a host that
+ *    lacks the model.
+ * 3. The advertising connection stays selectable.
+ * 4. Model advertised by both → both remain eligible (no over-filtering).
+ * 5. Provider with NO synced inventory at all → fail open, selection unchanged.
+ */
+
+import test from "node:test";
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+
+const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-chat-synced-11089-"));
+process.env.DATA_DIR = TEST_DATA_DIR;
+
+const core = await import("../../src/lib/db/core.ts");
+const providersDb = await import("../../src/lib/db/providers.ts");
+const modelsDb = await import("../../src/lib/db/models.ts");
+const auth = await import("../../src/sse/services/auth.ts");
+
+const PROVIDER = "ollama-local";
+
+async function resetStorage() {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+  fs.mkdirSync(TEST_DATA_DIR, { recursive: true });
+}
+
+test.after(() => {
+  core.resetDbInstance();
+  fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true });
+});
+
+async function createConnection(data: Record<string, unknown>): Promise<string> {
+  const created = (await providersDb.createProviderConnection(data)) as { id: string };
+  return created.id;
+}
+
+/** The connection id the selector handed back, or null if it returned no account. */
+function selectedConnectionId(selected: unknown): string | null {
+  if (!selected || typeof selected !== "object") return null;
+  const id = (selected as { connectionId?: unknown }).connectionId;
+  return typeof id === "string" ? id : null;
+}
+
+/** Create the two-host ollama-local topology from the issue report. */
+async function seedTwoHosts(options: { studioRateLimitedUntil?: string } = {}) {
+  const studioId = await createConnection({
+    provider: PROVIDER,
+    authType: "none",
+    name: "Mac Studio",
+    baseUrl: "http://studio.lan:11434/v1",
+    priority: 1,
+    isActive: true,
+  });
+  const jetsonId = await createConnection({
+    provider: PROVIDER,
+    authType: "none",
+    name: "Jetson",
+    baseUrl: "http://jetson.lan:11434/v1",
+    priority: 2,
+    isActive: true,
+  });
+
+  await modelsDb.replaceSyncedAvailableModelsForConnection(PROVIDER, studioId, [
+    { id: "gemma3:4b", name: "gemma3:4b" },
+    { id: "flux2-klein:9b", name: "flux2-klein:9b" },
+  ]);
+  await modelsDb.replaceSyncedAvailableModelsForConnection(PROVIDER, jetsonId, [
+    { id: "gemma3:4b", name: "gemma3:4b" },
+  ]);
+
+  if (options.studioRateLimitedUntil) {
+    await providersDb.updateProviderConnection(studioId, {
+      rateLimitedUntil: options.studioRateLimitedUntil,
+    });
+  }
+
+  return { studioId, jetsonId };
+}
+
+test("#11089 selects only the host whose synced inventory advertises the model", async () => {
+  await resetStorage();
+  const { studioId, jetsonId } = await seedTwoHosts();
+
+  // Exclude studio to force the selector to look elsewhere. Jetson does not
+  // advertise flux2-klein:9b, so it must NOT be handed back.
+  const selected = await auth.getProviderCredentials(PROVIDER, studioId, null, "flux2-klein:9b");
+
+  assert.notEqual(
+    selectedConnectionId(selected),
+    jetsonId,
+    "jetson never synced flux2-klein:9b and must not be selected for it"
+  );
+});
+
+test("#11089 does not preemptively fail over to a host lacking the model when the owner is cooling", async () => {
+  await resetStorage();
+  const coolingUntil = new Date(Date.now() + 10 * 60 * 1000).toISOString();
+  const { jetsonId } = await seedTwoHosts({ studioRateLimitedUntil: coolingUntil });
+
+  const selected = await auth.getProviderCredentials(PROVIDER, null, null, "flux2-klein:9b");
+
+  assert.notEqual(
+    selectedConnectionId(selected),
+    jetsonId,
+    "a cooling studio must surface a cooldown, not silently route to a host without the model"
+  );
+});
+
+test("#11089 keeps the connection that does advertise the model selectable", async () => {
+  await resetStorage();
+  const { studioId } = await seedTwoHosts();
+
+  const selected = await auth.getProviderCredentials(PROVIDER, null, null, "flux2-klein:9b");
+
+  assert.equal(
+    selectedConnectionId(selected),
+    studioId,
+    "studio advertises flux2-klein:9b and must be selected"
+  );
+});
+
+test("#11089 a model advertised by every host leaves both connections eligible", async () => {
+  await resetStorage();
+  const { studioId, jetsonId } = await seedTwoHosts();
+
+  const first = await auth.getProviderCredentials(PROVIDER, null, null, "gemma3:4b");
+  assert.equal(
+    selectedConnectionId(first),
+    studioId,
+    "fill-first prefers priority 1 for a shared model"
+  );
+
+  // Excluding studio (the normal account-fallback path) must still reach jetson,
+  // because jetson genuinely advertises gemma3:4b.
+  const second = await auth.getProviderCredentials(PROVIDER, studioId, null, "gemma3:4b");
+  assert.equal(
+    selectedConnectionId(second),
+    jetsonId,
+    "jetson advertises gemma3:4b and must remain a valid failover"
+  );
+});
+
+test("#11089 fails open when the provider has no synced inventory at all", async () => {
+  await resetStorage();
+
+  const connectionId = await createConnection({
+    provider: PROVIDER,
+    authType: "none",
+    baseUrl: "http://127.0.0.1:11434/v1",
+    priority: 1,
+    isActive: true,
+  });
+
+  // No replaceSyncedAvailableModelsForConnection call: discovery never ran.
+  // Routing must behave exactly as before rather than filtering everything out.
+  const selected = await auth.getProviderCredentials(PROVIDER, null, null, "never-synced-model");
+
+  assert.equal(
+    selectedConnectionId(selected),
+    connectionId,
+    "an unsynced provider must not be filtered to zero candidates"
+  );
+});