fix(modality-bridge): harden audio catalog and response header

src/app/(dashboard)/dashboard/settings/components/modalityBridge/ModalityBridgeAudioTab.tsx

@@ -114,6 +114,7 @@ export default function ModalityBridgeAudioTab() {
           placeholder={t("modalityBridgeAudioModelAuto")}
           allowEmpty
           modelFilter={isSttModel}
+          modelSource="catalog"
           onChange={(value) => void update({ modalityBridgeAudioModel: value })}
           className="text-sm"
         />

src/app/api/models/catalog/route.ts

@@ -38,6 +38,7 @@ export async function GET(request: Request) {
         id: model.id,
         name: model.name || model.root || model.id,
         type: model.type || "chat",
+        ...(typeof model.subtype === "string" ? { subtype: model.subtype } : {}),
         custom: model.custom === true,
         ...(model.free === true ? { free: true } : {}),
         ...(model.capabilities ? { capabilities: model.capabilities } : {}),

src/lib/guardrails/modalityBridge/bridgeStats.ts

@@ -48,6 +48,12 @@ interface GuardrailMetaEntry {
   meta?: Record<string, unknown> | null;
 }
 
+function headerModelToken(value: unknown): string {
+  return String(value ?? "unknown")
+    .slice(0, 200)
+    .replace(/[^A-Za-z0-9._~/-]/g, "_");
+}
+
 /** Response header value for a describe-bridged request; null when untouched. */
 export function buildModalityBridgeHeader(results: GuardrailMetaEntry[]): string | null {
   const segments: string[] = [];
@@ -59,7 +65,7 @@ export function buildModalityBridgeHeader(results: GuardrailMetaEntry[]): string
       !meta.rerouted
     ) {
       segments.push(
-        `image->text;model=${String(meta.visionModel ?? "unknown")};parts=${meta.imagesProcessed}`
+        `image->text;model=${headerModelToken(meta.visionModel)};parts=${meta.imagesProcessed}`
       );
     }
     if (
@@ -68,7 +74,7 @@ export function buildModalityBridgeHeader(results: GuardrailMetaEntry[]): string
       !meta.rerouted
     ) {
       segments.push(
-        `audio->text;model=${String(meta.sttModel ?? "unknown")};parts=${meta.clipsProcessed}`
+        `audio->text;model=${headerModelToken(meta.sttModel)};parts=${meta.clipsProcessed}`
       );
     }
   }

src/shared/components/ModelSelectField.tsx

@@ -25,6 +25,8 @@ export interface ModelSelectFieldProps {
   allowEmpty?: boolean;
   /** Optional catalog predicate, e.g. restrict the picker to STT models. */
   modelFilter?: (model: ApiModel) => boolean;
+  /** Model API to read. The unified catalog includes specialty audio/video surfaces. */
+  modelSource?: "available" | "catalog";
   className?: string;
 }
 
@@ -33,6 +35,35 @@ interface FetchState {
   options: { value: string; label: string }[];
 }
 
+function asRecord(value: unknown): Record<string, unknown> | null {
+  return value && typeof value === "object" ? (value as Record<string, unknown>) : null;
+}
+
+function readCatalogModels(value: unknown): ApiModel[] {
+  const catalog = asRecord(asRecord(value)?.catalog);
+  if (!catalog) return [];
+
+  const models: ApiModel[] = [];
+  for (const [provider, rawBucket] of Object.entries(catalog)) {
+    const bucket = asRecord(rawBucket);
+    if (!Array.isArray(bucket?.models)) continue;
+    for (const rawModel of bucket.models) {
+      const model = asRecord(rawModel);
+      const id = typeof model?.id === "string" ? model.id : "";
+      if (!id) continue;
+      const providerPrefix = `${provider}/`;
+      models.push({
+        provider,
+        model: id.startsWith(providerPrefix) ? id.slice(providerPrefix.length) : id,
+        fullModel: id.startsWith(providerPrefix) ? id : `${providerPrefix}${id}`,
+        type: typeof model?.type === "string" ? model.type : undefined,
+        subtype: typeof model?.subtype === "string" ? model.subtype : undefined,
+      });
+    }
+  }
+  return models;
+}
+
 /**
  * hidePaid-aware model picker (#6540). Loads options from `GET /api/models`
  * (already filters by `hidePaidModels`) instead of a static catalog. Falls
@@ -51,17 +82,24 @@ export default function ModelSelectField({
   allowCustom = true,
   allowEmpty = false,
   modelFilter,
+  modelSource = "available",
   className,
 }: ModelSelectFieldProps) {
   const [state, setState] = useState<FetchState>({ status: "loading", options: [] });
 
   useEffect(() => {
     let cancelled = false;
-    fetch("/api/models")
+    const endpoint = modelSource === "catalog" ? "/api/models/catalog" : "/api/models";
+    fetch(endpoint)
       .then((res) => (res.ok ? res.json() : Promise.reject(new Error("fetch failed"))))
       .then((data) => {
         if (cancelled) return;
-        const models: ApiModel[] = Array.isArray(data?.models) ? data.models : [];
+        const models: ApiModel[] =
+          modelSource === "catalog"
+            ? readCatalogModels(data)
+            : Array.isArray(data?.models)
+              ? data.models
+              : [];
         const filteredModels = modelFilter ? models.filter(modelFilter) : models;
         const options = filteredModels.map((m) => {
           const full = m.fullModel || `${m.provider}/${m.model}`;
@@ -75,7 +113,7 @@ export default function ModelSelectField({
     return () => {
       cancelled = true;
     };
-  }, [modelFilter]);
+  }, [modelFilter, modelSource]);
 
   if (state.status === "error" && allowCustom) {
     return (

tests/unit/guardrails/audioBridge.test.ts

@@ -264,4 +264,16 @@ test("audio transparency header is emitted only for transformed clips", () => {
     ]),
     null
   );
+  assert.equal(
+    buildModalityBridgeHeader([
+      {
+        guardrail: "audio-bridge",
+        meta: {
+          clipsProcessed: 1,
+          sttModel: "deepgram/nova-3\r\nx-injected: yes",
+        },
+      },
+    ]),
+    "audio->text;model=deepgram/nova-3__x-injected__yes;parts=1"
+  );
 });

tests/unit/model-alias-route.test.ts

@@ -11,6 +11,7 @@ process.env.JWT_SECRET = process.env.JWT_SECRET || "model-alias-route-jwt";
 
 const core = await import("../../src/lib/db/core.ts");
 const modelsDb = await import("../../src/lib/db/models.ts");
+const providersDb = await import("../../src/lib/db/providers.ts");
 const localDb = await import("../../src/lib/localDb.ts");
 const route = await import("../../src/app/api/models/alias/route.ts");
 const catalogRoute = await import("../../src/app/api/models/catalog/route.ts");
@@ -86,6 +87,15 @@ test("model alias route requires a dashboard session when management auth is ena
 });
 
 test("api models catalog route reuses the unified catalog diagnostics headers", async () => {
+  await providersDb.createProviderConnection({
+    provider: "deepgram",
+    authType: "apikey",
+    name: "deepgram-audio-catalog",
+    apiKey: "dg-test",
+    isActive: true,
+    testStatus: "active",
+  });
+  v1Catalog.__resetCatalogBuilderRunsForTest();
   const response = await catalogRoute.GET(
     new Request("http://localhost/api/models/catalog", {
       headers: { "x-request-id": "req-model-catalog-1" },
@@ -98,6 +108,11 @@ test("api models catalog route reuses the unified catalog diagnostics headers",
   assert.match(response.headers.get("X-Model-Catalog-Version") || "", /^model-metadata-v1:/);
   assert.equal(typeof body.catalog, "object");
   assert.equal(typeof body.catalogVersion, "string");
+  const nova = body.catalog.deepgram.models.find(
+    (model: { id?: string }) => model.id === "deepgram/nova-3"
+  );
+  assert.equal(nova.type, "audio");
+  assert.equal(nova.subtype, "transcription");
 });
 
 test("v1 models catalog emits diagnostics headers alongside the OpenAI-compatible list", async () => {

tests/unit/ui/modality-bridge-audio-tab.test.tsx

@@ -28,20 +28,24 @@ describe("ModalityBridgeAudioTab", () => {
     (globalThis as { IS_REACT_ACT_ENVIRONMENT?: boolean }).IS_REACT_ACT_ENVIRONMENT = true;
     fetchMock = vi.fn(async (input: RequestInfo | URL, init?: RequestInit) => {
       const url = String(input);
-      if (url.includes("/api/models")) {
+      if (url.includes("/api/models/catalog")) {
         return Response.json({
-          models: [
-            {
-              provider: "deepgram",
-              model: "nova-3",
-              type: "audio",
-              subtype: "transcription",
+          catalog: {
+            deepgram: {
+              provider: "Deepgram",
+              models: [
+                { id: "deepgram/nova-3", type: "audio", subtype: "transcription" },
+                { id: "deepgram/aura", type: "audio", subtype: "speech" },
+              ],
             },
-            { provider: "deepgram", model: "aura", type: "audio", subtype: "speech" },
-            { provider: "openai", model: "gpt-5.6" },
-          ],
+            openai: {
+              provider: "OpenAI",
+              models: [{ id: "openai/gpt-5.6", type: "chat" }],
+            },
+          },
         });
       }
+      if (url.includes("/api/models")) return Response.json({ models: [] });
       if (url.includes("/api/modality-bridge/stats")) {
         return Response.json({
           vision: { bridged: 0, cacheHits: 0, failures: 0, lastUsedAt: null },
@@ -99,6 +103,7 @@ describe("ModalityBridgeAudioTab", () => {
 
   it("shows only transcription models and exposes selectable Auto", async () => {
     const el = await render();
+    expect(fetchMock).toHaveBeenCalledWith("/api/models/catalog");
     await waitFor(
       () =>
         Array.from(el.querySelectorAll("option")).some(