Raise the fastmcp floor to 4.0 and bound it below 5 (#374)

Author: lesnik512

docs/integrations/fastmcp.md

@@ -62,6 +62,11 @@ FastMcpConfig(
 Enabled, each message is logged with its `method`, `source` and `type`, plus `duration` in
 nanoseconds. A message that raises is logged at exception level and the exception is re-raised.
 
+lite-bootstrap 2.0 requires fastmcp 4, where this log sees every message a client sends. That
+includes notifications such as `notifications/initialized` and `notifications/cancelled`, the
+`server/discover` request of a modern connection, and requests that fail before reaching a handler.
+On fastmcp 3 it saw only routable requests.
+
 Set `health_checks_enabled=False` to omit the health route.
 
 ## Sentry

pyproject.toml

@@ -174,11 +174,10 @@ faststream-all = [
     "lite-bootstrap[sentry,otl,logging,faststream,faststream-metrics,pyroscope]"
 ]
 fastmcp = [
-    # >=3.0 for fastmcp.server.providers.Provider and FastMCP.add_provider()
-    # (FastMcpBootstrapper registers its teardown through them --
-    # docs/adr/0001-fastmcp-teardown-via-provider-lifespan.md).
-    "fastmcp>=3.0",
-    # fastmcp 3.0 pulls py-key-value-aio, which requires typing-extensions>=4.15.
+    # >=4.0 so one middleware dispatch model is supported: from 4.0 the access log's on_message sees
+    # every inbound message, notifications included. <5 until 5.x is tested.
+    "fastmcp>=4.0,<5",
+    # fastmcp 4.0 pulls py-key-value-aio 0.4.4, which requires typing-extensions>=4.15.
     "typing-extensions>=4.15",
 ]
 fastmcp-otl = [
@@ -188,7 +187,7 @@ fastmcp-otl = [
 fastmcp-metrics = [
     "lite-bootstrap[fastmcp]",
     "prometheus-client>=0.20",
-    # >=8.0.1 to share the fastapi-metrics floor; it requires starlette>=1.0, which fastmcp 3.0 already pulls.
+    # >=8.0.1 to share the fastapi-metrics floor; it requires starlette>=1.0, which fastmcp 4.0 already pulls.
     "prometheus-fastapi-instrumentator>=8.0.1",
 ]
 fastmcp-all = [

tests/test_fastmcp_bootstrap.py

@@ -131,6 +131,25 @@ async def call_next(received: MiddlewareContext[typing.Any]) -> dict[str, str]:
     assert isinstance(call_kwargs.kwargs["duration"], int)
 
 
+async def test_fastmcp_access_log_records_notifications(monkeypatch: pytest.MonkeyPatch) -> None:
+    fake_logger = MagicMock()
+    monkeypatch.setattr(fastmcp_bootstrapper, "fastmcp_access_logger", fake_logger)
+    bootstrapper = FastMcpBootstrapper(bootstrap_config=_make_test_config(logging_access_log_enabled=True))
+    application = bootstrapper.bootstrap()
+    try:
+        async with Client(application, mode="legacy") as client:
+            await client.list_tools()
+    finally:
+        bootstrapper.teardown()
+
+    logged = [(call.kwargs["mcp"]["method"], call.kwargs["mcp"]["type"]) for call in fake_logger.info.call_args_list]
+    assert logged == [
+        ("initialize", "request"),
+        ("notifications/initialized", "notification"),
+        ("tools/list", "request"),
+    ]
+
+
 async def test_fastmcp_logging_middleware_logs_exception(monkeypatch: pytest.MonkeyPatch) -> None:
     fake_logger = MagicMock()
     monkeypatch.setattr(