feat(deps): upgrade fastmcp from 2.x to 3.x

Upgrade fastmcp dependency from >=2.14.4,<3 to >=3.3.1,<4.
Remove standalone mcp dependency (transitive via fastmcp 3.x).

In FastMCP 3.x, @mcp.tool returns the original function instead of
a FunctionTool wrapper. Update tests to call search_documents()
directly instead of search_documents.fn(), and replace FunctionTool
isinstance checks with plain callable/coroutine assertions.

Signed-off-by: Major Hayden <major@redhat.com>

Author: major

CHANGELOG.md

@@ -24,6 +24,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Changed
 
+- Upgraded fastmcp from 2.x to 3.x (`>=3.3.1, <4`)
+- Removed standalone `mcp` dependency (pulled in transitively by fastmcp 3.x)
+- Updated smoke tests to match FastMCP 3.x decorator behavior (`@mcp.tool` now returns the original function)
 - CI workflow: extended ruff check and format to cover `src/`, `tests/`, and `demos/`
 - Makefile: `lint` target now runs `ruff check --fix` (was `ruff check`)
 - pytest: added `--cov=docs2db_mcp --cov-report=term-missing` to default options

pyproject.toml

@@ -31,8 +31,7 @@ classifiers = [
 ]
 
 dependencies = [
-    "fastmcp >=2.14.4, <3",
-    "mcp >=1.27.1",
+    "fastmcp >=3.3.1, <4",
     "docs2db-api",
     "pydantic >=2.13.4",
     "pydantic-settings >=2.14.1",

tests/test_search_documents.py

@@ -8,7 +8,7 @@ async def test_valid_query_returns_chunks(self, mock_engine, sample_documents):
         from docs2db_mcp.tools.search_documents import search_documents
 
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query="RHEL 9 security features")
+            result = await search_documents(query="RHEL 9 security features")
 
         assert "chunks" in result
         assert "query_used" in result
@@ -21,7 +21,7 @@ async def test_chunk_structure(self, mock_engine):
         from docs2db_mcp.tools.search_documents import search_documents
 
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query="RHEL packages")
+            result = await search_documents(query="RHEL packages")
 
         assert result["num_results"] > 0
         chunk = result["chunks"][0]
@@ -35,7 +35,7 @@ async def test_chunk_data_maps_correctly(self, mock_engine, sample_documents):
         from docs2db_mcp.tools.search_documents import search_documents
 
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query="RHEL security")
+            result = await search_documents(query="RHEL security")
 
         first_chunk = result["chunks"][0]
         first_doc = sample_documents[0]
@@ -48,7 +48,7 @@ async def test_engine_called_with_correct_params(self, mock_engine):
 
         mock_get_engine = AsyncMock(return_value=mock_engine)
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=mock_get_engine):
-            await search_documents.fn(
+            await search_documents(
                 query="test query",
                 max_chunks=10,
                 similarity_threshold=0.8,
@@ -67,7 +67,7 @@ async def test_default_params_forwarded(self, mock_engine):
 
         mock_get_engine = AsyncMock(return_value=mock_engine)
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=mock_get_engine):
-            await search_documents.fn(query="test")
+            await search_documents(query="test")
 
         mock_engine.search_documents.assert_called_once_with(
             query="test",
@@ -81,15 +81,15 @@ async def test_query_used_is_original_query(self, mock_engine):
 
         original_query = "How to configure firewalld in RHEL?"
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query=original_query)
+            result = await search_documents(query=original_query)
 
         assert result["query_used"] == original_query
 
     async def test_multiple_chunks_order_preserved(self, mock_engine, sample_documents):
         from docs2db_mcp.tools.search_documents import search_documents
 
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query="RHEL documentation")
+            result = await search_documents(query="RHEL documentation")
 
         assert result["num_results"] == len(sample_documents)
         for chunk, doc in zip(result["chunks"], sample_documents, strict=True):
@@ -106,7 +106,7 @@ async def test_empty_results_returns_zero_chunks(self):
         mock_engine.search_documents = AsyncMock(return_value=empty_result)
 
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query="nonexistent topic")
+            result = await search_documents(query="nonexistent topic")
 
         assert result["chunks"] == []
         assert result["num_results"] == 0
@@ -122,7 +122,7 @@ async def test_empty_results_preserves_query(self):
 
         query = "obscure topic that returns nothing"
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query=query)
+            result = await search_documents(query=query)
 
         assert result["query_used"] == query
 
@@ -133,7 +133,7 @@ async def test_connection_error_returns_error_dict(self):
 
         mock_get_engine = AsyncMock(side_effect=ConnectionError("Database unreachable"))
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=mock_get_engine):
-            result = await search_documents.fn(query="test query")
+            result = await search_documents(query="test query")
 
         assert "error" in result
         assert result["chunks"] == []
@@ -145,7 +145,7 @@ async def test_search_error_returns_error_dict(self, mock_engine):
 
         mock_engine.search_documents = AsyncMock(side_effect=RuntimeError("Search failed"))
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query="test query")
+            result = await search_documents(query="test query")
 
         assert "error" in result
         assert result["chunks"] == []
@@ -158,7 +158,7 @@ async def test_error_preserves_original_query(self):
         mock_get_engine = AsyncMock(side_effect=Exception("Unexpected error"))
         original_query = "RHEL 10 features"
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=mock_get_engine):
-            result = await search_documents.fn(query=original_query)
+            result = await search_documents(query=original_query)
 
         assert result["query_used"] == original_query
 
@@ -167,7 +167,7 @@ async def test_timeout_error_handled_gracefully(self):
 
         mock_get_engine = AsyncMock(side_effect=TimeoutError())
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=mock_get_engine):
-            result = await search_documents.fn(query="slow query")
+            result = await search_documents(query="slow query")
 
         assert "error" in result
         assert result["chunks"] == []
@@ -178,7 +178,7 @@ async def test_generic_exception_handled_gracefully(self):
 
         mock_get_engine = AsyncMock(side_effect=Exception("Something went wrong"))
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=mock_get_engine):
-            result = await search_documents.fn(query="test")
+            result = await search_documents(query="test")
 
         assert "error" in result
         assert "Something went wrong" in result["error"]
@@ -199,7 +199,7 @@ async def test_optional_fields_default_to_none(self):
         mock_engine.search_documents = AsyncMock(return_value=mock_result)
 
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query="minimal test")
+            result = await search_documents(query="minimal test")
 
         chunk = result["chunks"][0]
         assert chunk["text"] == "Minimal document chunk"
@@ -212,7 +212,7 @@ async def test_similarity_is_float(self, mock_engine):
         from docs2db_mcp.tools.search_documents import search_documents
 
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query="test")
+            result = await search_documents(query="test")
 
         for chunk in result["chunks"]:
             assert isinstance(chunk["similarity"], float)
@@ -221,14 +221,14 @@ async def test_rerank_score_preserved(self, mock_engine, sample_documents):
         from docs2db_mcp.tools.search_documents import search_documents
 
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query="test")
+            result = await search_documents(query="test")
 
         assert result["chunks"][0]["rerank_score"] == sample_documents[0]["rerank_score"]
 
     async def test_vector_similarity_preserved(self, mock_engine, sample_documents):
         from docs2db_mcp.tools.search_documents import search_documents
 
         with patch("docs2db_mcp.tools.search_documents.get_engine", new=AsyncMock(return_value=mock_engine)):
-            result = await search_documents.fn(query="test")
+            result = await search_documents(query="test")
 
         assert result["chunks"][0]["vector_similarity"] == sample_documents[0]["vector_similarity"]

tests/test_smoke.py

@@ -45,17 +45,15 @@ def test_shutdown_engine_is_async(self):
         assert asyncio.iscoroutinefunction(shutdown_engine)
 
     def test_search_documents_tool_exists(self):
-        from fastmcp.tools.tool import FunctionTool
-
         from docs2db_mcp.tools import search_documents
 
-        assert isinstance(search_documents, FunctionTool)
-        assert search_documents.name == "search_documents"
+        assert callable(search_documents)
+        assert search_documents.__name__ == "search_documents"
 
     def test_search_documents_fn_is_async(self):
         from docs2db_mcp.tools import search_documents
 
-        assert asyncio.iscoroutinefunction(search_documents.fn)
+        assert asyncio.iscoroutinefunction(search_documents)
 
 
 class TestConfigDefaults:
@@ -143,10 +141,8 @@ def test_mcp_server_is_configured(self):
         assert mcp is not None
 
     def test_search_documents_registered(self):
-        from fastmcp.tools.tool import FunctionTool
-
         from docs2db_mcp.tools import search_documents
 
-        assert isinstance(search_documents, FunctionTool)
-        assert search_documents.name == "search_documents"
-        assert search_documents.enabled
+        assert callable(search_documents)
+        assert search_documents.__name__ == "search_documents"
+        assert asyncio.iscoroutinefunction(search_documents)