feat: pytest support

README.md

@@ -78,6 +78,9 @@ uv run ${test_file} \
     --conformance_input=test_data/flower_shop/conformance_input.json \
     --fixture_config=test_data/flower_shop/test_fixtures.json
 done
+
+# Or, if you prefer:
+SERVER_URL=http://localhost:${MERCHANT_SERVER_PORT} SIMULATION_SECRET=${SIMULATION_SECRET} uv run pytest
 ```
 
 ### Customizing Test Fixtures

conftest.py

@@ -0,0 +1,20 @@
+#   Copyright 2026 UCP Authors
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+"""Configuration file for pytest."""
+
+from integration_test_utils import FLAGS
+
+
+FLAGS(["pytest"])

integration_test_utils.py

@@ -17,6 +17,7 @@
 import csv
 import json
 import logging
+import os
 from pathlib import Path
 import threading
 import time
@@ -57,10 +58,12 @@ class UnifiedUpdate(CheckoutUpdateRequest):
 
 FLAGS = flags.FLAGS
 try:
-  flags.DEFINE_string("server_url", None, "Base URL of the server")
+  flags.DEFINE_string(
+    "server_url", os.getenv("SERVER_URL"), "Base URL of the server"
+  )
   flags.DEFINE_string(
     "simulation_secret",
-    str(uuid.uuid4()),
+    os.getenv("SIMULATION_SECRET", str(uuid.uuid4())),
     "Secret for simulation endpoints",
   )
   flags.DEFINE_integer(

pyproject.toml

@@ -15,6 +15,7 @@ dependencies = [
     "fastapi>=0.109.0",
     "uvicorn[standard]>=0.38.0",
     "ruff>=0.14.11",
+    "pytest>=8.0.0",
 ]
 
 [dependency-groups]