Merge pull request #2 from mrexodia/resources

Add support for MCP resources

Author: mrexodia

README.md

@@ -172,6 +172,26 @@ def divide(
     return numerator / denominator
 ```
 
+## Resources
+
+Expose read-only data via URI patterns. Resources are serialized as JSON.
+
+```python
+from typing import Annotated
+
+@mcp.resource("file://data.txt")
+def read_file() -> dict:
+    """Get information about data.txt"""
+    return {"name": "data.txt", "size": 1024}
+
+@mcp.resource("file://{filename}")
+def read_any_file(
+    filename: Annotated[str, "Name of file to read"]
+) -> dict:
+    """Get information about any file"""
+    return {"name": filename, "size": 2048}
+```
+
 ## Supported clients
 
 The following clients have been tested:

examples/mcp_example.py

@@ -78,6 +78,18 @@ def struct_get(
         for name in (names if isinstance(names, list) else [names])
     ]
 
+@mcp.resource("example://system_info")
+def system_info_resource() -> SystemInfo:
+    """Resource providing system information"""
+    return get_system_info()
+
+@mcp.resource("example://greeting/{name}")
+def greeting_resource(
+    name: Annotated[str, "Name to greet from resource"]
+) -> GreetingResponse:
+    """Resource providing greeting message"""
+    return greet(name)
+
 if __name__ == "__main__":
     parser = argparse.ArgumentParser(description="MCP Example Server")
     parser.add_argument("--stdio", action="store_true", help="Run MCP server over stdio")
@@ -87,8 +99,8 @@ def struct_get(
     else:
         print("Starting MCP Example Server...")
         print("\nAvailable tools:")
-        for name in mcp.tools.methods.keys():
-            func = mcp.tools.methods[name]
+        for name in mcp._tools.methods.keys():
+            func = mcp._tools.methods[name]
             print(f"  - {name}: {func.__doc__}")
 
         mcp.serve("127.0.0.1", 5001)
@@ -103,4 +115,3 @@ def struct_get(
         except KeyboardInterrupt:
             print("\n\nStopping server...")
             mcp.stop()
-            print("Server stopped.")

src/zeromcp/jsonrpc.py

@@ -2,7 +2,7 @@
 import types
 import inspect
 import traceback
-from typing import Any, Callable, get_type_hints, get_origin, get_args, Union, TypedDict, TypeAlias, NotRequired
+from typing import Any, Callable, get_type_hints, get_origin, get_args, Union, TypedDict, TypeAlias, NotRequired, is_typeddict
 
 JsonRpcId: TypeAlias = str | int | float | None
 JsonRpcParams: TypeAlias = dict[str, Any] | list[Any] | None
@@ -168,6 +168,10 @@ def _call(self, method: str, params: Any) -> Any:
                         arg_origin = get_origin(arg_type)
                         check_type = arg_origin if arg_origin is not None else arg_type
 
+                        # TypedDict cannot be used with isinstance - check for dict instead
+                        if is_typeddict(arg_type):
+                            check_type = dict
+
                         if isinstance(value, check_type):
                             type_matched = True
                             break
@@ -187,6 +191,16 @@ def _call(self, method: str, params: Any) -> Any:
                     validated_params[param_name] = value
                     continue
 
+                # Handle TypedDict (must check before basic types)
+                if is_typeddict(expected_type):
+                    if not isinstance(value, dict):
+                        raise JsonRpcException(
+                            -32602,
+                            f"Invalid params: {param_name} expected dict, got {type(value).__name__}"
+                        )
+                    validated_params[param_name] = value
+                    continue
+
                 # Handle basic types
                 if isinstance(expected_type, type):
                     # Allow int -> float conversion