diff --git a/gui/main.py b/gui/main.py
index 998aa27..8510de7 100644
--- a/gui/main.py
+++ b/gui/main.py
@@ -18,28 +18,52 @@
 import customtkinter as ctk
 
 from crab import Experiment
-from crab.agents.backend_models import OpenAIModel
+from crab.agents.backend_models import OpenAIModel, ClaudeModel, GeminiModel
 from crab.agents.policies import SingleAgentPolicy
 from gui.utils import get_benchmark
 
 warnings.filterwarnings("ignore")
 
+AVAILABLE_MODELS = {
+    "gpt-4o": ("OpenAIModel", "gpt-4o"),
+    "gpt-4turbo": ("OpenAIModel", "gpt-4-turbo"),
+    "gemini": ("GeminiModel", "gemini-1.5-pro-latest"),
+    "claude": ("ClaudeModel", "claude-3-opus-20240229"),
+}
+
+def get_model_instance(model_key: str):
+    if model_key not in AVAILABLE_MODELS:
+        raise ValueError(f"Model {model_key} not supported")
+    
+    model_config = AVAILABLE_MODELS[model_key]
+    model_class_name = model_config[0]
+    model_name = model_config[1]
+
+    if model_class_name == "OpenAIModel":
+        return OpenAIModel(model=model_name, history_messages_len=2)
+    elif model_class_name == "GeminiModel":
+        return GeminiModel(model=model_name, history_messages_len=2)
+    elif model_class_name == "ClaudeModel":
+        return ClaudeModel(model=model_name, history_messages_len=2)
 
 def assign_task():
     task_description = input_entry.get()
     input_entry.delete(0, "end")
     display_message(task_description)
 
+    model = get_model_instance(selected_model.get())
+    agent_policy = SingleAgentPolicy(model_backend=model)
+
     task_id = str(uuid4())
     benchmark = get_benchmark(task_id, task_description)
-    expeirment = Experiment(
+    experiment = Experiment(
         benchmark=benchmark,
         task_id=task_id,
         agent_policy=agent_policy,
         log_dir=log_dir,
     )
     # TODO: redirect the output to the GUI
-    expeirment.start_benchmark()
+    experiment.start_benchmark()
 
 
 def display_message(message, sender="user"):
@@ -56,9 +80,7 @@ def display_message(message, sender="user"):
 
 
 if __name__ == "__main__":
-    # TODO: make this choosable by the user
-    model = OpenAIModel(model="gpt-4o", history_messages_len=2)
-    agent_policy = SingleAgentPolicy(model_backend=model)
+    # TODO: Handle JSON decode error from environment action endpoint and display model response in GUI
     log_dir = (Path(__file__).parent / "logs").resolve()
 
     ctk.set_appearance_mode("System")
@@ -68,6 +90,20 @@ def display_message(message, sender="user"):
     app.title("CRAB")
     app.geometry("400x500")
 
+    model_frame = ctk.CTkFrame(app)
+    model_frame.pack(pady=10, padx=10, fill="x")
+
+    model_label = ctk.CTkLabel(model_frame, text="Select Model:")
+    model_label.pack(side="left", padx=(0, 10))
+
+    selected_model = ctk.StringVar(value="gpt-4o")
+    model_dropdown = ctk.CTkOptionMenu(
+        model_frame,
+        values=list(AVAILABLE_MODELS.keys()),
+        variable=selected_model,
+    )
+    model_dropdown.pack(side="left", fill="x", expand=True)
+
     chat_display_frame = ctk.CTkFrame(app, width=380, height=380)
     chat_display_frame.pack(pady=10)
     chat_display = ctk.CTkTextbox(