feat(v1beta): use stored token limits and metadata in Gemini models endpoint

src/app/api/v1beta/models/route.ts

@@ -1,5 +1,6 @@
 import { CORS_ORIGIN } from "@/shared/utils/cors";
 import { PROVIDER_MODELS } from "@/shared/constants/models";
+import { getAllCustomModels } from "@/lib/db/models";
 
 /**
  * Handle CORS preflight
@@ -16,13 +17,13 @@ export async function OPTIONS() {
 
 /**
  * GET /v1beta/models - Gemini compatible models list
- * Returns models in Gemini API format
+ * Returns models in Gemini API format with real token limits when available.
  */
 export async function GET() {
   try {
-    // Collect all models from all providers
     const models = [];
 
+    // Built-in models (hardcoded defaults)
     for (const [provider, providerModels] of Object.entries(PROVIDER_MODELS)) {
       for (const model of providerModels) {
         models.push({
@@ -36,8 +37,34 @@ export async function GET() {
       }
     }
 
+    // Custom models (use stored metadata from provider APIs)
+    try {
+      const customModelsMap = (await getAllCustomModels()) as Record<string, unknown>;
+      for (const [providerId, rawModels] of Object.entries(customModelsMap)) {
+        if (!Array.isArray(rawModels)) continue;
+        for (const model of rawModels) {
+          if (!model || typeof model !== "object" || typeof (model as any).id !== "string") continue;
+          const m = model as Record<string, unknown>;
+          if (m.isHidden === true) continue;
+          models.push({
+            name: `models/${providerId}/${m.id}`,
+            displayName: m.name || m.id,
+            ...(typeof m.description === "string" ? { description: m.description } : {}),
+            supportedGenerationMethods: ["generateContent"],
+            inputTokenLimit:
+              typeof m.inputTokenLimit === "number" ? m.inputTokenLimit : 128000,
+            outputTokenLimit:
+              typeof m.outputTokenLimit === "number" ? m.outputTokenLimit : 8192,
+            ...(m.supportsThinking === true ? { thinking: true } : {}),
+          });
+        }
+      }
+    } catch {
+      // Custom models are optional — skip on error
+    }
+
     return Response.json({ models });
-  } catch (error) {
+  } catch (error: any) {
     console.log("Error fetching models:", error);
     return Response.json({ error: { message: error.message } }, { status: 500 });
   }