From b53e0902991b43d1e9f32774849b5c87b4d4c178 Mon Sep 17 00:00:00 2001
From: Henry Wildermuth <hmwildermuth@gmail.com>
Date: Thu, 13 Feb 2025 14:21:50 -0800
Subject: [PATCH] Update URL validation to allow file and other nonstandard
schemas
---
.../mcp_simple_resource/server.py | 7 +++---
src/mcp/types.py | 24 ++++++++++++-------
2 files changed, 19 insertions(+), 12 deletions(-)
diff --git a/examples/servers/simple-resource/mcp_simple_resource/server.py b/examples/servers/simple-resource/mcp_simple_resource/server.py
index 11ba5692..0ec1d926 100644
--- a/examples/servers/simple-resource/mcp_simple_resource/server.py
+++ b/examples/servers/simple-resource/mcp_simple_resource/server.py
@@ -2,7 +2,7 @@
import click
import mcp.types as types
from mcp.server.lowlevel import Server
-from pydantic import AnyUrl
+from pydantic import FileUrl
SAMPLE_RESOURCES = {
"greeting": "Hello! This is a sample text resource.",
@@ -26,7 +26,7 @@ def main(port: int, transport: str) -> int:
async def list_resources() -> list[types.Resource]:
return [
types.Resource(
- uri=AnyUrl(f"file:///{name}.txt"),
+ uri=FileUrl(f"file:///{name}.txt"),
name=name,
description=f"A sample text resource named {name}",
mimeType="text/plain",
@@ -35,8 +35,7 @@ async def list_resources() -> list[types.Resource]:
]
@app.read_resource()
- async def read_resource(uri: AnyUrl) -> str | bytes:
- assert uri.path is not None
+ async def read_resource(uri: FileUrl) -> str | bytes:
name = uri.path.replace(".txt", "").lstrip("/")
if name not in SAMPLE_RESOURCES:
diff --git a/src/mcp/types.py b/src/mcp/types.py
index d1157aa6..7d867bd3 100644
--- a/src/mcp/types.py
+++ b/src/mcp/types.py
@@ -1,7 +1,15 @@
-from typing import Annotated, Any, Callable, Generic, Literal, TypeAlias, TypeVar
+from typing import (
+ Annotated,
+ Any,
+ Callable,
+ Generic,
+ Literal,
+ TypeAlias,
+ TypeVar,
+)
from pydantic import BaseModel, ConfigDict, Field, FileUrl, RootModel
-from pydantic.networks import AnyUrl
+from pydantic.networks import AnyUrl, UrlConstraints
"""
Model Context Protocol bindings for Python
@@ -353,7 +361,7 @@ class Annotations(BaseModel):
class Resource(BaseModel):
"""A known resource that the server is capable of reading."""
- uri: AnyUrl
+ uri: Annotated[AnyUrl, UrlConstraints(host_required=False)]
"""The URI of this resource."""
name: str
"""A human-readable name for this resource."""
@@ -415,7 +423,7 @@ class ListResourceTemplatesResult(PaginatedResult):
class ReadResourceRequestParams(RequestParams):
"""Parameters for reading a resource."""
- uri: AnyUrl
+ uri: Annotated[AnyUrl, UrlConstraints(host_required=False)]
"""
The URI of the resource to read. The URI can use any protocol; it is up to the
server how to interpret it.
@@ -433,7 +441,7 @@ class ReadResourceRequest(Request):
class ResourceContents(BaseModel):
"""The contents of a specific resource or sub-resource."""
- uri: AnyUrl
+ uri: Annotated[AnyUrl, UrlConstraints(host_required=False)]
"""The URI of this resource."""
mimeType: str | None = None
"""The MIME type of this resource, if known."""
@@ -476,7 +484,7 @@ class ResourceListChangedNotification(Notification):
class SubscribeRequestParams(RequestParams):
"""Parameters for subscribing to a resource."""
- uri: AnyUrl
+ uri: Annotated[AnyUrl, UrlConstraints(host_required=False)]
"""
The URI of the resource to subscribe to. The URI can use any protocol; it is up to
the server how to interpret it.
@@ -497,7 +505,7 @@ class SubscribeRequest(Request):
class UnsubscribeRequestParams(RequestParams):
"""Parameters for unsubscribing from a resource."""
- uri: AnyUrl
+ uri: Annotated[AnyUrl, UrlConstraints(host_required=False)]
"""The URI of the resource to unsubscribe from."""
model_config = ConfigDict(extra="allow")
@@ -515,7 +523,7 @@ class UnsubscribeRequest(Request):
class ResourceUpdatedNotificationParams(NotificationParams):
"""Parameters for resource update notifications."""
- uri: AnyUrl
+ uri: Annotated[AnyUrl, UrlConstraints(host_required=False)]
"""
The URI of the resource that has been updated. This might be a sub-resource of the
one that the client actually subscribed to.