server.py•4.93 kB
import asyncio
from mcp.server.models import InitializationOptions
import mcp.types as types
from mcp.server import NotificationOptions, Server
from pydantic import AnyUrl
import mcp.server.stdio
# Store notes as a simple key-value dict to demonstrate state management
notes: dict[str, str] = {}
server = Server("mcp-server-on-raspi")
@server.list_resources()
async def handle_list_resources() -> list[types.Resource]:
"""
List available note resources.
Each note is exposed as a resource with a custom note:// URI scheme.
"""
return [
types.Resource(
uri=AnyUrl(f"note://internal/{name}"),
name=f"Note: {name}",
description=f"A simple note named {name}",
mimeType="text/plain",
)
for name in notes
]
@server.read_resource()
async def handle_read_resource(uri: AnyUrl) -> str:
"""
Read a specific note's content by its URI.
The note name is extracted from the URI host component.
"""
if uri.scheme != "note":
raise ValueError(f"Unsupported URI scheme: {uri.scheme}")
name = uri.path
if name is not None:
name = name.lstrip("/")
return notes[name]
raise ValueError(f"Note not found: {name}")
@server.list_prompts()
async def handle_list_prompts() -> list[types.Prompt]:
"""
List available prompts.
Each prompt can have optional arguments to customize its behavior.
"""
return [
types.Prompt(
name="summarize-notes",
description="Creates a summary of all notes",
arguments=[
types.PromptArgument(
name="style",
description="Style of the summary (brief/detailed)",
required=False,
)
],
)
]
@server.get_prompt()
async def handle_get_prompt(
name: str, arguments: dict[str, str] | None
) -> types.GetPromptResult:
"""
Generate a prompt by combining arguments with server state.
The prompt includes all current notes and can be customized via arguments.
"""
if name != "summarize-notes":
raise ValueError(f"Unknown prompt: {name}")
style = (arguments or {}).get("style", "brief")
detail_prompt = " Give extensive details." if style == "detailed" else ""
return types.GetPromptResult(
description="Summarize the current notes",
messages=[
types.PromptMessage(
role="user",
content=types.TextContent(
type="text",
text=f"Here are the current notes to summarize:{detail_prompt}\n\n"
+ "\n".join(
f"- {name}: {content}"
for name, content in notes.items()
),
),
)
],
)
@server.list_tools()
async def handle_list_tools() -> list[types.Tool]:
"""
List available tools.
Each tool specifies its arguments using JSON Schema validation.
"""
return [
types.Tool(
name="add-note",
description="Add a new note",
inputSchema={
"type": "object",
"properties": {
"name": {"type": "string"},
"content": {"type": "string"},
},
"required": ["name", "content"],
},
)
]
@server.call_tool()
async def handle_call_tool(
name: str, arguments: dict | None
) -> list[types.TextContent | types.ImageContent | types.EmbeddedResource]:
"""
Handle tool execution requests.
Tools can modify server state and notify clients of changes.
"""
if name != "add-note":
raise ValueError(f"Unknown tool: {name}")
if not arguments:
raise ValueError("Missing arguments")
note_name = arguments.get("name")
content = arguments.get("content")
if not note_name or not content:
raise ValueError("Missing name or content")
# Update server state
notes[note_name] = content
# Notify clients that resources have changed
await server.request_context.session.send_resource_list_changed()
return [
types.TextContent(
type="text",
text=f"Added note '{note_name}' with content: {content}",
)
]
async def main():
# Run the server using stdin/stdout streams
async with mcp.server.stdio.stdio_server() as (read_stream, write_stream):
await server.run(
read_stream,
write_stream,
InitializationOptions(
server_name="mcp-server-on-raspi",
server_version="0.1.0",
capabilities=server.get_capabilities(
notification_options=NotificationOptions(),
experimental_capabilities={},
),
),
)