Scenario Testing

1import pytest
2import scenario
3from kern.agent import Agent
4from kern.models.openai import OpenAIResponses
5
6# Configure Scenario defaults (model for user simulator and judge)
7scenario.configure(default_model="openai/gpt-4.1-mini")
8
9@pytest.mark.agent_test
10@pytest.mark.asyncio
11async def test_vegetarian_recipe_agent() -> None:
12    # 1. Define an AgentAdapter to wrap your agent
13    class VegetarianRecipeAgentAdapter(scenario.AgentAdapter):
14        agent: Agent
15
16        def __init__(self) -> None:
17            self.agent = Agent(
18                model=OpenAIResponses(id="gpt-5.2"),
19                markdown=True,
20                debug_mode=True,
21                instructions="You are a vegetarian recipe agent.",
22            )
23
24        async def call(self, input: scenario.AgentInput) -> scenario.AgentReturnTypes:
25            response = self.agent.run(
26                input=input.last_new_user_message_str(), # Pass only the last user message
27                session_id=input.thread_id, # Pass the thread id, this allows the agent to track history
28            )
29            return response.content
30
31    # 2. Run the scenario simulation
32    result = await scenario.run(
33        name="dinner recipe request",
34        description="User is looking for a vegetarian dinner idea.",
35        agents=[
36            VegetarianRecipeAgentAdapter(),
37            scenario.UserSimulatorAgent(),
38            scenario.JudgeAgent(
39                criteria=[
40                    "Agent should not ask more than two follow-up questions",
41                    "Agent should generate a recipe",
42                    "Recipe should include a list of ingredients",
43                    "Recipe should include step-by-step cooking instructions",
44                    "Recipe should be vegetarian and not include any sort of meat",
45                ]
46            ),
47        ],
48    )
49
50    # 3. Assert and inspect the result
51    assert result.success