From ec74c0293d6cfb40d7f8ee37fdc16455bd68a0e1 Mon Sep 17 00:00:00 2001
From: Jeremiah Lowin <153965+jlowin@users.noreply.github.com>
Date: Mon, 2 Dec 2024 12:47:36 -0500
Subject: [PATCH 1/2] Remove BaseURL reference and use AnyURL

---
 src/fastmcp/resources/base.py | 29 +++++++++--------------------
 1 file changed, 9 insertions(+), 20 deletions(-)

diff --git a/src/fastmcp/resources/base.py b/src/fastmcp/resources/base.py
index bde9b38..11f9029 100644
--- a/src/fastmcp/resources/base.py
+++ b/src/fastmcp/resources/base.py
@@ -1,34 +1,16 @@
 """Base classes and interfaces for FastMCP resources."""
 
 import abc
-from typing import Annotated, Union
+from typing import Union
 
 from pydantic import (
     AnyUrl,
     BaseModel,
-    BeforeValidator,
     ConfigDict,
     Field,
-    FileUrl,
     ValidationInfo,
     field_validator,
 )
-from pydantic.networks import _BaseUrl  # TODO: remove this once pydantic is updated
-
-
-def maybe_cast_str_to_any_url(x) -> AnyUrl:
-    if isinstance(x, FileUrl):
-        return x
-    elif isinstance(x, AnyUrl):
-        return x
-    elif isinstance(x, str):
-        if x.startswith("file://"):
-            return FileUrl(x)
-        return AnyUrl(x)
-    raise ValueError(f"Expected str or AnyUrl, got {type(x)}")
-
-
-LaxAnyUrl = Annotated[_BaseUrl | str, BeforeValidator(maybe_cast_str_to_any_url)]
 
 
 class Resource(BaseModel, abc.ABC):
@@ -36,7 +18,8 @@ class Resource(BaseModel, abc.ABC):
 
     model_config = ConfigDict(validate_default=True)
 
-    uri: LaxAnyUrl = Field(default=..., description="URI of the resource")
+    # uri: Annotated[AnyUrl, BeforeValidator(maybe_cast_str_to_any_url)] = Field(
+    uri: AnyUrl = Field(default=..., description="URI of the resource")
     name: str | None = Field(description="Name of the resource", default=None)
     description: str | None = Field(
         description="Description of the resource", default=None
@@ -47,6 +30,12 @@ class Resource(BaseModel, abc.ABC):
         pattern=r"^[a-zA-Z0-9]+/[a-zA-Z0-9\-+.]+$",
     )
 
+    @field_validator("uri", mode="before")
+    def validate_uri(cls, uri: AnyUrl | str) -> AnyUrl:
+        if isinstance(uri, str):
+            return AnyUrl(uri)
+        return uri
+
     @field_validator("name", mode="before")
     @classmethod
     def set_default_name(cls, name: str | None, info: ValidationInfo) -> str:

From 73b06f81d3d0de3e4f81c0f62a08aca5f13b11d8 Mon Sep 17 00:00:00 2001
From: Jeremiah Lowin <153965+jlowin@users.noreply.github.com>
Date: Mon, 2 Dec 2024 12:55:20 -0500
Subject: [PATCH 2/2] Use FileURL where possible

---
 src/fastmcp/resources/base.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/fastmcp/resources/base.py b/src/fastmcp/resources/base.py
index 11f9029..28b0834 100644
--- a/src/fastmcp/resources/base.py
+++ b/src/fastmcp/resources/base.py
@@ -8,6 +8,7 @@
     BaseModel,
     ConfigDict,
     Field,
+    FileUrl,
     ValidationInfo,
     field_validator,
 )
@@ -33,6 +34,9 @@ class Resource(BaseModel, abc.ABC):
     @field_validator("uri", mode="before")
     def validate_uri(cls, uri: AnyUrl | str) -> AnyUrl:
         if isinstance(uri, str):
+            # AnyUrl doesn't support triple-slashes, but files do ("file:///absolute/path")
+            if uri.startswith("file://"):
+                return FileUrl(uri)
             return AnyUrl(uri)
         return uri