diff --git a/packages/backend/src/routes/ai/chat.ts b/packages/backend/src/routes/ai/chat.ts
index be9b2e3..2df3241 100644
--- a/packages/backend/src/routes/ai/chat.ts
+++ b/packages/backend/src/routes/ai/chat.ts
@@ -10,7 +10,7 @@ export default async function aiChat(req: AuthedRequest) {
     const parsed = parseQueryParams(url, ChatRequestSchema);
     if ("error" in parsed) return parsed.error;
 
-    const { orgId, projectId, message } = parsed.data;
+    const { orgId, projectId, message, model } = parsed.data;
 
     const user = await getUserById(req.userId);
     if (!user) {
@@ -20,7 +20,7 @@ export default async function aiChat(req: AuthedRequest) {
     const context = await buildContext(orgId, projectId, user);
 
     const fullPrompt = `${SYSTEM_PROMPT}\n\n${context}\n\n<user_query>${message}</user_query>`;
-    const response = await callAI(fullPrompt);
+    const response = await callAI(fullPrompt, model);
 
     return Response.json(response);
 }
diff --git a/packages/frontend/src/lib/query/hooks/chat.ts b/packages/frontend/src/lib/query/hooks/chat.ts
index 4bb162c..83eaa93 100644
--- a/packages/frontend/src/lib/query/hooks/chat.ts
+++ b/packages/frontend/src/lib/query/hooks/chat.ts
@@ -2,7 +2,7 @@ import type { ChatRequest, ChatResponse, ModelsResponse } from "@sprint/shared";
 import { useMutation } from "@tanstack/react-query";
 import { apiClient } from "@/lib/server";
 
-export function useChatMutation() {
+export function useChat() {
   return useMutation<ChatResponse, Error, ChatRequest>({
     mutationKey: ["ai", "chat"],
     mutationFn: async (input) => {
diff --git a/packages/shared/src/api-schemas.ts b/packages/shared/src/api-schemas.ts
index 6c37e6f..a2c7e39 100644
--- a/packages/shared/src/api-schemas.ts
+++ b/packages/shared/src/api-schemas.ts
@@ -671,6 +671,7 @@ export const ChatRequestSchema = z.object({
     orgId: z.coerce.number().int().positive("orgId must be a positive integer"),
     projectId: z.coerce.number().int().positive("projectId must be a positive integer"),
     message: z.string().min(1, "Message is required"),
+    model: z.string().min(1, "Model is required"),
 });
 
 export type ChatRequest = z.infer<typeof ChatRequestSchema>;