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LiteMCP

LiteMCP is an ASGI-compatible Model Context Protocol (MCP) server built on FastAPI. It provides a decorator-based API for registering tools, prompts, and resources.

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Class Definition

from agentor.mcp.server import LiteMCP

class LiteMCP(MCPAPIRouter)
Inherits from MCPAPIRouter and adds ASGI compatibility with FastAPI.

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Constructor

app = LiteMCP(**kwargs)
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**kwargs
dict
Additional arguments passed to MCPAPIRouter. Common options:
  • name (str): Server name (default: “agentor-mcp-server”)
  • version (str): Server version (default: “0.1.0”)
  • instructions (str): Instructions for using the server
  • prefix (str): URL prefix for MCP endpoints (default: “/mcp”)
  • website_url (str): Server website URL
  • icons (List[Icon]): Server icons
  • dependencies (List[Callable]): FastAPI dependencies

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Methods

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serve()

Run the server with uvicorn. 
app.serve(
    host="0.0.0.0",
    port=8000,
    enable_cors=True,
    **uvicorn_kwargs
)
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host
str
default:"0.0.0.0"
Host to bind the server to
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port
int
default:"8000"
Port to bind the server to
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enable_cors
bool
default:"true"
Whether to enable CORS middleware with permissive settings
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**uvicorn_kwargs
dict
Additional arguments passed to uvicorn.run(), such as:
  • reload (bool): Enable auto-reload
  • log_level (str): Logging level (“debug”, “info”, “warning”, “error”)
  • workers (int): Number of worker processes

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run()

Deprecated. Use serve() instead. 
app.run(*args, **kwargs)

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Decorators

LiteMCP inherits all decorators from MCPAPIRouter:
  • @app.tool() - Register a tool
  • @app.prompt() - Register a prompt
  • @app.resource() - Register a resource
  • @app.method() - Register a custom MCP method handler
See MCPAPIRouter for detailed decorator documentation.

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ASGI Interface

LiteMCP implements the ASGI interface via __call__, making it compatible with any ASGI server: 
async def __call__(scope: dict, receive: Any, send: Any) -> None
This allows you to use LiteMCP with uvicorn CLI: 
uvicorn mymodule:app --host 0.0.0.0 --port 8000 --reload

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Example Usage

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Basic Server

from agentor.mcp.server import LiteMCP

# Create the ASGI app
app = LiteMCP(
    name="my-mcp-server",
    version="1.0.0",
    instructions="A simple MCP server example",
)

# Register a tool
@app.tool(description="Get weather for a location")
def get_weather(location: str) -> str:
    """Get current weather for a location"""
    return f"Weather in {location}: Sunny, 72°F"

# Register a prompt
@app.prompt(description="Generate a greeting")
def greeting(name: str, style: str = "formal") -> str:
    """Generate a personalized greeting"""
    if style == "formal":
        return f"Good day, {name}. How may I assist you today?"
    else:
        return f"Hey {name}! What's up?"

# Register a resource
@app.resource(
    uri="config://settings",
    name="Settings",
    mime_type="application/json"
)
def get_settings(uri: str) -> str:
    """Get application settings"""
    return '{"theme": "dark", "language": "en"}'

if __name__ == "__main__":
    # Run with default settings
    app.serve()

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Running with Different Methods

# Method 1: Direct run (simplest)
app.serve()

# Method 2: Run with custom uvicorn settings
app.serve(reload=True, log_level="debug")

# Method 3: Use with uvicorn CLI
# $ uvicorn mymodule:app --host 0.0.0.0 --port 8000 --reload

# Method 4: Programmatic uvicorn
import uvicorn
uvicorn.run(app, host="0.0.0.0", port=8000)

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Custom Configuration

from mcp.types import Icon

app = LiteMCP(
    name="weather-mcp-server",
    version="2.0.0",
    instructions="Provides weather information and forecasts",
    prefix="/api/mcp",
    website_url="https://example.com",
    icons=[Icon(url="https://example.com/icon.png", type="image/png")],
)

# Run with CORS disabled and custom port
app.serve(host="127.0.0.1", port=9000, enable_cors=False)

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See Also

Last modified on March 4, 2026