perf(langchain): add benchmark command (#36641)

add benchmark in Makefile

libs/langchain_v1/Makefile

@@ -1,4 +1,4 @@
-.PHONY: all start_services stop_services coverage coverage_agents test test_fast extended_tests test_watch test_watch_extended integration_tests check_imports check_version lint format type lint_diff format_diff lint_package lint_tests help
+.PHONY: all start_services stop_services coverage coverage_agents test test_fast benchmark extended_tests test_watch test_watch_extended integration_tests check_imports check_version lint format type lint_diff format_diff lint_package lint_tests help
 
 # Default target executed when no arguments are given to make.
 all: help
@@ -46,6 +46,9 @@ test:
 test_fast:
 	LANGGRAPH_TEST_FAST=1 uv run --group test pytest -n auto $(PYTEST_EXTRA) --disable-socket --allow-unix-socket $(TEST_FILE)
 
+benchmark:
+	uv run --group test pytest tests/benchmarks/test_create_agent.py -m benchmark
+
 extended_tests:
 	make start_services && LANGGRAPH_TEST_FAST=0 uv run --group test pytest --disable-socket --allow-unix-socket --only-extended tests/unit_tests; \
 	EXIT_CODE=$$?; \
@@ -117,6 +120,7 @@ help:
 	@echo 'coverage_agents              - run middleware and agent tests with coverage report'
 	@echo 'test                         - run unit tests with all services'
 	@echo 'test_fast                    - run unit tests with in-memory services only'
+	@echo 'benchmark                    - run the create_agent benchmark quickly'
 	@echo 'tests                        - run unit tests (alias for "make test")'
 	@echo 'test TEST_FILE=<test_file>   - run all tests in file'
 	@echo 'extended_tests               - run only extended unit tests'

libs/langchain_v1/pyproject.toml

@@ -68,6 +68,7 @@ test = [
     "pytest-socket>=0.6.0,<1.0.0",
     "pytest-xdist<4.0.0,>=3.6.1",
     "pytest-mock",
+    "pytest-benchmark>=5.1.0,<6.0.0",
     "syrupy>=4.0.2,<6.0.0",
     "toml>=0.10.2,<1.0.0",
     "blockbuster>=1.5.26,<1.6.0",
@@ -189,6 +190,7 @@ markers = [
     "requires: mark tests as requiring a specific library",
     "scheduled: mark tests to run in scheduled testing",
     "compile: mark placeholder test used to compile integration tests without running them",
+    "benchmark: mark benchmark tests",
 ]
 asyncio_mode = "auto"
 filterwarnings = [

libs/langchain_v1/tests/benchmarks/test_create_agent.py

@@ -0,0 +1,14 @@
+import pytest
+from langchain_core.language_models.fake_chat_models import GenericFakeChatModel
+from langchain_core.messages import AIMessage
+from pytest_benchmark.fixture import BenchmarkFixture
+
+from langchain.agents import create_agent
+
+
+@pytest.mark.benchmark
+def test_create_agent_instantiation(benchmark: BenchmarkFixture) -> None:
+    def instantiate_agent() -> None:
+        create_agent(model=GenericFakeChatModel(messages=iter([AIMessage(content="ok")])))
+
+    benchmark(instantiate_agent)

libs/langchain_v1/uv.lock

@@ -1986,6 +1986,7 @@ test = [
     { name = "langchain-tests" },
     { name = "pytest" },
     { name = "pytest-asyncio" },
+    { name = "pytest-benchmark" },
     { name = "pytest-cov" },
     { name = "pytest-mock" },
     { name = "pytest-socket" },
@@ -2040,6 +2041,7 @@ test = [
     { name = "langchain-tests", editable = "../standard-tests" },
     { name = "pytest", specifier = ">=8.0.0,<10.0.0" },
     { name = "pytest-asyncio", specifier = ">=0.23.2,<2.0.0" },
+    { name = "pytest-benchmark", specifier = ">=5.1.0,<6.0.0" },
     { name = "pytest-cov", specifier = ">=4.0.0,<8.0.0" },
     { name = "pytest-mock" },
     { name = "pytest-socket", specifier = ">=0.6.0,<1.0.0" },