fix(byok): skip Vercel BYOK for Kilo-exclusive models (#3001)

* feat(byok): exclude Kilo-exclusive models from user BYOK

Kilo-exclusive models must always be served through Kilo's own providers
and never through a user's BYOK key. This change:

- Adds isKiloExclusiveModel helper
- Skips BYOK lookup (direct and Vercel) in getProvider for Kilo-exclusive models
- Filters Kilo-exclusive models out of the listSupportedModels response
  used by the BYOK selection screen

* refactor(byok): only skip Vercel BYOK for Kilo-exclusive models

Direct BYOK is unaffected — it targets dedicated OpenAI-compatible
providers by model ID prefix and does not overlap with Kilo-exclusive
models. Expanded the comment to explain why Vercel is incompatible:
the Vercel AI Gateway speaks upstream-native API shapes, whereas
Kilo-exclusive models live behind generic OpenAI-compatible endpoints
with our own request/response transforms.

* refactor(byok): move Kilo-exclusive check into checkVercelBYOK

Pushes the filter down to where it belongs and clarifies that the core
incompatibility is reasoning: the Vercel AI Gateway normalizes reasoning
to upstream-native shapes, whereas Kilo-exclusive models go through
generic OpenAI-compatible endpoints with transforms we apply ourselves.

* fix(byok): exclude disabled models from isKiloExclusiveModel

Matches the convention used by findKiloExclusiveModel and
isKiloExclusiveFreeModel: disabled exclusive models shouldn't be treated
as Kilo-exclusive for routing/filtering purposes.

* docs(byok): drop 'transforms we apply ourselves' from comment

---------

Co-authored-by: kiloconnect[bot] <240665456+kiloconnect[bot]@users.noreply.github.com>

Author: kilo-code-bot[bot]

apps/web/src/lib/ai-gateway/models.ts

@@ -82,6 +82,10 @@ export function isKiloExclusiveFreeModel(model: string): boolean {
   );
 }
 
+export function isKiloExclusiveModel(model: string): boolean {
+  return kiloExclusiveModels.some(m => m.public_id === model && m.status !== 'disabled');
+}
+
 export const kiloExclusiveModels = [
   gemma_4_26b_a4b_it_free_model,
   minimax_m25_free_model,

apps/web/src/lib/ai-gateway/providers/get-provider.ts

@@ -1,6 +1,6 @@
 import type { GatewayRequest } from '@/lib/ai-gateway/providers/openrouter/types';
 import { shouldRouteToVercel } from '@/lib/ai-gateway/providers/vercel';
-import { kiloExclusiveModels } from '@/lib/ai-gateway/models';
+import { isKiloExclusiveModel, kiloExclusiveModels } from '@/lib/ai-gateway/models';
 import {
   getBYOKforOrganization,
   getBYOKforUser,
@@ -132,6 +132,13 @@ async function checkVercelBYOK(
   organizationId: string | undefined
 ): Promise<BYOKResult[] | null> {
   if (isAnonymousContext(user)) return null;
+  // Kilo-exclusive models are not routable through Vercel BYOK. Reasoning in particular
+  // breaks: the Vercel AI Gateway normalizes reasoning to each provider's upstream-native
+  // shape, whereas our Kilo-exclusive models are served through generic OpenAI-compatible
+  // endpoints (Martian, direct Alibaba, etc.) where that normalization doesn't apply and the
+  // response ends up corrupted. Skip the Vercel BYOK lookup entirely and let the caller fall
+  // through to the model's declared gateway.
+  if (isKiloExclusiveModel(requestedModel)) return null;
   const modelProviders = await getModelUserByokProviders(requestedModel);
   if (modelProviders.length === 0) return null;
   return organizationId

apps/web/src/routers/byok-router.ts

@@ -34,6 +34,7 @@ import { decryptByokRow } from '@/lib/ai-gateway/byok';
 import type { GatewayProviderOptions } from '@ai-sdk/gateway';
 import { mapModelIdToVercel } from '@/lib/ai-gateway/providers/vercel/mapModelIdToVercel';
 import { isCodestralModel } from '@/lib/ai-gateway/providers/mistral';
+import { isKiloExclusiveModel } from '@/lib/ai-gateway/models';
 import DIRECT_BYOK_PROVIDERS from '@/lib/ai-gateway/providers/direct-byok/direct-byok-definitions';
 import {
   createAiSdkProvider,
@@ -106,6 +107,7 @@ async function fetchSupportedModels(): Promise<Record<string, string[]>> {
   result['codestral'] = ['Codestral (mistralai/codestral-2508)'];
 
   for (const openRouterModel of Object.values(openRouterModelMetadata)) {
+    if (isKiloExclusiveModel(openRouterModel.id)) continue;
     const vercelModel = vercelModelMetadata[mapModelIdToVercel(openRouterModel.id, false)];
     if (!vercelModel) continue;
     if (isCodestralModel(vercelModel.id)) continue;