fix deprecation warnings

README.md

@@ -113,7 +113,7 @@ For development, install with:
 git clone https://github.com/jlowin/fastmcp.git
 cd fastmcp
 # Install with dev dependencies
-uv sync --dev
+uv sync
 ```
 
 ## Quickstart
@@ -589,7 +589,7 @@ Contributions make the open-source community vibrant! We welcome improvements an
 #### Setup
 
 1.  Clone: `git clone https://github.com/jlowin/fastmcp.git && cd fastmcp`
-2.  Install Env & Dependencies: `uv venv && uv sync --dev` (Activate the `.venv` after creation)
+2.  Install Env & Dependencies: `uv venv && uv sync` (Activate the `.venv` after creation)
 
 #### Testing
 

pyproject.toml

@@ -16,12 +16,6 @@ requires-python = ">=3.10"
 readme = "README.md"
 license = { text = "Apache-2.0" }
 
-[project.scripts]
-fastmcp = "fastmcp.cli:app"
-
-[project.optional-dependencies]
-
-
 [dependency-groups]
 dev = [
     "pre-commit",
@@ -36,23 +30,32 @@ dev = [
     "pdbpp>=0.10.3",
     "dirty-equals>=0.9.0",
 ]
+
+[project.scripts]
+fastmcp = "fastmcp.cli:app"
+
 [build-system]
-requires = ["hatchling>=1.21.0", "hatch-vcs>=0.4.0"]
+requires = ["hatchling", "uv-dynamic-versioning>=0.7.0"]
 build-backend = "hatchling.build"
 
+[tool.hatch.version]
+source = "uv-dynamic-versioning"
+
+[tool.uv-dynamic-versioning]
+vcs = "git"
+style = "pep440"
+bump = true
+fallback-version = "0.0.0"
+
 [tool.uv]
-# no default groups
-default-groups = []
+# uncomment to omit `dev` default group
+# default-groups = []
 
 [tool.pytest.ini_options]
 asyncio_mode = "auto"
 asyncio_default_fixture_loop_scope = "session"
-filterwarnings = [
-    "ignore:Accessing the 'model_fields' attribute on the instance is deprecated:DeprecationWarning",
-]
+filterwarnings = []
 
-[tool.hatch.version]
-source = "vcs"
 
 [tool.pyright]
 include = ["src", "tests"]
@@ -67,7 +70,7 @@ venvPath = "."
 venv = ".venv"
 
 [tool.ruff.lint]
-extend-select = ["I"]
+extend-select = ["I", "UP"]
 
 [tool.ruff.lint.per-file-ignores]
 "__init__.py" = ["F401", "I001", "RUF013"]

src/fastmcp/utilities/func_metadata.py

@@ -27,7 +27,7 @@ class ArgModelBase(BaseModel):
         That is, sub-models etc are not dumped - they are kept as pydantic models.
         """
         kwargs: dict[str, Any] = {}
-        for field_name in self.model_fields.keys():
+        for field_name in self.__class__.model_fields.keys():
             kwargs[field_name] = getattr(self, field_name)
         return kwargs
 

src/fastmcp/utilities/openapi.py

@@ -1,6 +1,6 @@
 import json
 import logging
-from typing import Any, Literal, Union, cast
+from typing import Any, Literal, cast
 
 # Using the recommended library: openapi-pydantic
 from openapi_pydantic import (
@@ -92,7 +92,7 @@ __all__ = [
 
 
 def _resolve_ref(
-    item: Union[Reference, Schema, Parameter, RequestBody, Any], openapi: OpenAPI
+    item: Reference | Schema | Parameter | RequestBody | Any, openapi: OpenAPI
 ) -> Any:
     """Resolves a potential Reference object to its target definition (no changes needed here)."""
     if isinstance(item, Reference):
@@ -110,7 +110,7 @@ def _resolve_ref(
                 elif isinstance(target, BaseModel):
                     # Use model_extra for fields not explicitly defined (like components types)
                     # Check class fields first, then model_extra
-                    if part in target.model_fields:  # Access class attribute here
+                    if part in target.__class__.model_fields:
                         target = getattr(target, part, None)
                     elif target.model_extra and part in target.model_extra:
                         target = target.model_extra[part]
@@ -141,7 +141,7 @@ def _resolve_ref(
 
 
 def _extract_schema_as_dict(
-    schema_obj: Union[Schema, Reference], openapi: OpenAPI
+    schema_obj: Schema | Reference, openapi: OpenAPI
 ) -> JsonSchema:
     """Resolves a schema/reference and returns it as a dictionary."""
     resolved_schema = _resolve_ref(schema_obj, openapi)
@@ -177,8 +177,8 @@ def _convert_to_parameter_location(param_in: str) -> ParameterLocation:
 
 
 def _extract_parameters(
-    operation_params: list[Union[Parameter, Reference]] | None,
-    path_item_params: list[Union[Parameter, Reference]] | None,
+    operation_params: list[Parameter | Reference] | None,
+    path_item_params: list[Parameter | Reference] | None,
     openapi: OpenAPI,
 ) -> list[ParameterInfo]:
     """Extracts and resolves parameters using corrected attribute names."""

uv.lock

@@ -1,4 +1,5 @@
 version = 1
+revision = 1
 requires-python = ">=3.10"
 
 [[package]]
@@ -127,7 +128,7 @@ name = "click"
 version = "8.1.8"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
-    { name = "colorama", marker = "platform_system == 'Windows'" },
+    { name = "colorama", marker = "sys_platform == 'win32'" },
 ]
 sdist = { url = "https://files.pythonhosted.org/packages/b9/2e/0090cbf739cee7d23781ad4b89a9894a41538e4fcf4c31dcdd705b78eb8b/click-8.1.8.tar.gz", hash = "sha256:ed53c9d8990d83c2a27deae68e4ee337473f6330c040a31d4225c9574d16096a", size = 226593 }
 wheels = [
@@ -230,7 +231,7 @@ name = "fancycompleter"
 version = "0.9.1"
 source = { registry = "https://pypi.org/simple" }
 dependencies = [
-    { name = "pyreadline", marker = "platform_system == 'Windows'" },
+    { name = "pyreadline", marker = "sys_platform == 'win32'" },
     { name = "pyrepl" },
 ]
 sdist = { url = "https://files.pythonhosted.org/packages/a9/95/649d135442d8ecf8af5c7e235550c628056423c96c4bc6787348bdae9248/fancycompleter-0.9.1.tar.gz", hash = "sha256:09e0feb8ae242abdfd7ef2ba55069a46f011814a80fe5476be48f51b00247272", size = 10866 }
@@ -254,7 +255,6 @@ wheels = [
 
 [[package]]
 name = "fastmcp"
-version = "0.4.2.dev40+g8720a78.d20250410"
 source = { editable = "." }
 dependencies = [
     { name = "dotenv" },