diff --git a/apps/gui/src/app/config/page.tsx b/apps/gui/src/app/config/page.tsx
index f87ce26..7be8fd1 100644
--- a/apps/gui/src/app/config/page.tsx
+++ b/apps/gui/src/app/config/page.tsx
@@ -31,6 +31,7 @@ export default function ConfigPage() {
   const [editName, setEditName] = useState("");
   const [editProvider, setEditProvider] = useState("google-genai");
   const [editKey, setEditKey] = useState("");
+  const [editModel, setEditModel] = useState("gemini-2.5-flash");
   const [editIsActive, setEditIsActive] = useState(false);
 
   useEffect(() => {
@@ -38,6 +39,7 @@ export default function ConfigPage() {
       setEditName("");
       setEditProvider("google-genai");
       setEditKey("");
+      setEditModel("gemini-2.5-flash");
       setEditIsActive(false);
     } else {
       const inst = instances.find((i) => i.id === selectedInstanceId);
@@ -45,6 +47,7 @@ export default function ConfigPage() {
         setEditName(inst.name);
         setEditProvider(inst.providerName);
         setEditKey("");
+        setEditModel(inst.modelName || "gemini-2.5-flash");
         setEditIsActive(inst.isActive);
       }
     }
@@ -104,13 +107,13 @@ export default function ConfigPage() {
           setLoading(false);
           return;
         }
-        const created = await createProviderInstance(editName, editProvider, editKey);
+        const created = await createProviderInstance(editName, editProvider, editKey, editModel || undefined);
         if (editIsActive) {
           await setActiveProviderInstance(created.id);
         }
         setSelectedInstanceId(created.id);
       } else {
-        await updateProviderInstance(selectedInstanceId, editName, editProvider, editKey || undefined);
+        await updateProviderInstance(selectedInstanceId, editName, editProvider, editKey || undefined, editModel || undefined);
         if (editIsActive) {
           await setActiveProviderInstance(selectedInstanceId);
         }
@@ -251,6 +254,17 @@ export default function ConfigPage() {
                       />
                     </div>
 
+                    <div className="form-group">
+                      <label htmlFor="formModel">Model Name</label>
+                      <input
+                        id="formModel"
+                        type="text"
+                        value={editModel}
+                        onChange={(e) => setEditModel(e.target.value)}
+                        placeholder="e.g. gemini-2.5-flash, gemini-2.5-pro"
+                      />
+                    </div>
+
                     <div className="form-group checkbox-group">
                       <input
                         id="formActive"
diff --git a/apps/gui/src/app/play/actions.ts b/apps/gui/src/app/play/actions.ts
index 47c464c..a746bb1 100644
--- a/apps/gui/src/app/play/actions.ts
+++ b/apps/gui/src/app/play/actions.ts
@@ -242,8 +242,9 @@ export async function createProviderInstance(
   name: string,
   providerName: string,
   apiKey: string,
+  modelName?: string,
 ): Promise<LLMProviderInstance> {
-  return ProviderManager.create(name, providerName, apiKey);
+  return ProviderManager.create(name, providerName, apiKey, modelName);
 }
 
 export async function deleteProviderInstance(id: string): Promise<void> {
@@ -259,8 +260,9 @@ export async function updateProviderInstance(
   name: string,
   providerName: string,
   apiKey?: string,
+  modelName?: string,
 ): Promise<void> {
-  ProviderManager.update(id, name, providerName, apiKey);
+  ProviderManager.update(id, name, providerName, apiKey, modelName);
 }
 
 export async function getProviderMappings(): Promise<Record<string, string>> {
diff --git a/apps/gui/src/lib/provider-manager.ts b/apps/gui/src/lib/provider-manager.ts
index 9eac049..54e441c 100644
--- a/apps/gui/src/lib/provider-manager.ts
+++ b/apps/gui/src/lib/provider-manager.ts
@@ -19,9 +19,16 @@ function getSettingsDb() {
       name TEXT NOT NULL,
       providerName TEXT NOT NULL,
       apiKey TEXT NOT NULL,
-      isActive INTEGER NOT NULL DEFAULT 0
+      isActive INTEGER NOT NULL DEFAULT 0,
+      modelName TEXT
     )
   `).run();
+
+  try {
+    db.prepare(`ALTER TABLE provider_instances ADD COLUMN modelName TEXT`).run();
+  } catch {
+    // ignore
+  }
   
   return db;
 }
@@ -36,6 +43,7 @@ export class ProviderManager {
         providerName: string;
         apiKey: string;
         isActive: number;
+        modelName?: string;
       }[];
       return rows.map((r) => ({
         id: r.id,
@@ -43,13 +51,14 @@ export class ProviderManager {
         providerName: r.providerName,
         apiKey: r.apiKey,
         isActive: r.isActive === 1,
+        modelName: r.modelName || undefined,
       }));
     } finally {
       db.close();
     }
   }
 
-  static create(name: string, providerName: string, apiKey: string): LLMProviderInstance {
+  static create(name: string, providerName: string, apiKey: string, modelName?: string): LLMProviderInstance {
     const db = getSettingsDb();
     try {
       const id = "provider-" + Date.now();
@@ -57,11 +66,11 @@ export class ProviderManager {
       const isActive = activeCount.count === 0 ? 1 : 0;
       
       db.prepare(`
-        INSERT INTO provider_instances (id, name, providerName, apiKey, isActive)
-        VALUES (?, ?, ?, ?, ?)
-      `).run(id, name, providerName, apiKey, isActive);
+        INSERT INTO provider_instances (id, name, providerName, apiKey, isActive, modelName)
+        VALUES (?, ?, ?, ?, ?, ?)
+      `).run(id, name, providerName, apiKey, isActive, modelName || null);
       
-      return { id, name, providerName, apiKey, isActive: isActive === 1 };
+      return { id, name, providerName, apiKey, isActive: isActive === 1, modelName };
     } finally {
       db.close();
     }
@@ -94,21 +103,21 @@ export class ProviderManager {
     }
   }
 
-  static update(id: string, name: string, providerName: string, apiKey?: string): void {
+  static update(id: string, name: string, providerName: string, apiKey?: string, modelName?: string): void {
     const db = getSettingsDb();
     try {
       if (apiKey && apiKey.trim()) {
         db.prepare(`
           UPDATE provider_instances
-          SET name = ?, providerName = ?, apiKey = ?
+          SET name = ?, providerName = ?, apiKey = ?, modelName = ?
           WHERE id = ?
-        `).run(name, providerName, apiKey, id);
+        `).run(name, providerName, apiKey, modelName || null, id);
       } else {
         db.prepare(`
           UPDATE provider_instances
-          SET name = ?, providerName = ?
+          SET name = ?, providerName = ?, modelName = ?
           WHERE id = ?
-        `).run(name, providerName, id);
+        `).run(name, providerName, modelName || null, id);
       }
     } finally {
       db.close();
@@ -124,6 +133,7 @@ export class ProviderManager {
         providerName: string;
         apiKey: string;
         isActive: number;
+        modelName?: string;
       } | undefined;
       if (!row) return null;
       return {
@@ -132,6 +142,7 @@ export class ProviderManager {
         providerName: row.providerName,
         apiKey: row.apiKey,
         isActive: true,
+        modelName: row.modelName || undefined,
       };
     } finally {
       db.close();
diff --git a/packages/llm/src/llm.ts b/packages/llm/src/llm.ts
index 7c2550a..8e65d2c 100644
--- a/packages/llm/src/llm.ts
+++ b/packages/llm/src/llm.ts
@@ -43,4 +43,5 @@ export interface LLMProviderInstance {
   providerName: string;
   apiKey: string;
   isActive: boolean;
+  modelName?: string;
 }
diff --git a/packages/llm/src/providers/google-genai.ts b/packages/llm/src/providers/google-genai.ts
index 94faef9..83bff43 100644
--- a/packages/llm/src/providers/google-genai.ts
+++ b/packages/llm/src/providers/google-genai.ts
@@ -8,14 +8,14 @@ export class GeminiProvider implements ILLMProvider {
   private model: ChatGoogleGenerativeAI;
   lastCalls: LLMCallRecord[] = [];
 
-  constructor(apiKey?: string) {
+  constructor(apiKey?: string, modelName?: string) {
     const key = apiKey || llmConfig.GOOGLE_API_KEY;
     if (!key) {
       throw new Error("GOOGLE_API_KEY is required to initialize GeminiProvider");
     }
     this.model = new ChatGoogleGenerativeAI({
       apiKey: key,
-      model: "gemini-2.5-flash",
+      model: modelName || "gemini-2.5-flash",
     });
   }