"""
Entry point for running mcp-test-mcp as a module.
This module is executed when running:
python -m mcp_test_mcp
or when using the installed console script:
mcp-test-mcp
Supports multiple transports via CLI arguments and environment variables:
- stdio (default): Standard input/output for Claude Desktop/Code integration
- streamable-http: HTTP transport for web deployments
- sse: Server-Sent Events (legacy, for backward compatibility)
Examples:
mcp-test-mcp # default: stdio
mcp-test-mcp --transport stdio # explicit stdio
mcp-test-mcp --transport streamable-http # HTTP server
mcp-test-mcp --transport streamable-http --host 0.0.0.0 --port 8080
mcp-test-mcp --transport sse --port 9000 # legacy SSE
Environment Variables (CLI args take precedence):
MCP_TEST_TRANSPORT: Transport type (stdio, streamable-http, sse)
MCP_TEST_HOST: Host for HTTP transports (default: 127.0.0.1)
MCP_TEST_PORT: Port for HTTP transports (default: 8000)
"""
import argparse
import os
import sys
from typing import Optional
# Valid transport types
VALID_TRANSPORTS = ("stdio", "streamable-http", "sse")
# Default values
DEFAULT_TRANSPORT = "stdio"
DEFAULT_HOST = "127.0.0.1"
DEFAULT_PORT = 8000
def get_config_value(
cli_value: Optional[str],
env_var: str,
default: str,
) -> str:
"""Get configuration value with priority: CLI > env var > default.
Args:
cli_value: Value from command line argument (None if not provided)
env_var: Environment variable name to check
default: Default value if neither CLI nor env var is set
Returns:
The resolved configuration value
"""
if cli_value is not None:
return cli_value
env_value = os.environ.get(env_var)
if env_value is not None:
return env_value
return default
def get_port_value(
cli_value: Optional[int],
env_var: str,
default: int,
) -> int:
"""Get port configuration with priority: CLI > env var > default.
Args:
cli_value: Value from command line argument (None if not provided)
env_var: Environment variable name to check
default: Default value if neither CLI nor env var is set
Returns:
The resolved port value
"""
if cli_value is not None:
return cli_value
env_value = os.environ.get(env_var)
if env_value is not None:
try:
return int(env_value)
except ValueError:
print(
f"Warning: Invalid {env_var} value '{env_value}', using default {default}",
file=sys.stderr,
)
return default
return default
def parse_args(args: Optional[list[str]] = None) -> argparse.Namespace:
"""Parse command line arguments.
Args:
args: List of arguments to parse (defaults to sys.argv[1:])
Returns:
Parsed arguments namespace
"""
parser = argparse.ArgumentParser(
prog="mcp-test-mcp",
description="MCP testing server for testing other MCP servers",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog="""
Environment Variables:
MCP_TEST_TRANSPORT Transport type (stdio, streamable-http, sse)
MCP_TEST_HOST Host for HTTP transports (default: 127.0.0.1)
MCP_TEST_PORT Port for HTTP transports (default: 8000)
Priority: CLI arguments > environment variables > defaults
Examples:
%(prog)s # Use stdio transport (default)
%(prog)s --transport streamable-http # HTTP server on 127.0.0.1:8000
%(prog)s --transport streamable-http --host 0.0.0.0 --port 8080
%(prog)s --transport sse --port 9000 # Legacy SSE transport
""",
)
parser.add_argument(
"--transport",
"-t",
choices=VALID_TRANSPORTS,
default=None,
help="Transport protocol to use (default: stdio, or MCP_TEST_TRANSPORT env var)",
)
parser.add_argument(
"--host",
"-H",
default=None,
help="Host to bind for HTTP transports (default: 127.0.0.1, or MCP_TEST_HOST env var)",
)
parser.add_argument(
"--port",
"-p",
type=int,
default=None,
help="Port to bind for HTTP transports (default: 8000, or MCP_TEST_PORT env var)",
)
return parser.parse_args(args)
def resolve_config(args: argparse.Namespace) -> dict:
"""Resolve final configuration from CLI args and environment variables.
Args:
args: Parsed command line arguments
Returns:
Dictionary with resolved transport, host, and port values
"""
transport = get_config_value(args.transport, "MCP_TEST_TRANSPORT", DEFAULT_TRANSPORT)
# Validate transport
if transport not in VALID_TRANSPORTS:
valid_opts = ", ".join(VALID_TRANSPORTS)
print(
f"Error: Invalid transport '{transport}'. Must be one of: {valid_opts}",
file=sys.stderr,
)
sys.exit(1)
host = get_config_value(args.host, "MCP_TEST_HOST", DEFAULT_HOST)
port = get_port_value(args.port, "MCP_TEST_PORT", DEFAULT_PORT)
return {
"transport": transport,
"host": host,
"port": port,
}
def main(args: Optional[list[str]] = None) -> None:
"""Main entry point for the MCP server.
Args:
args: Optional list of arguments (for testing). Defaults to sys.argv[1:].
"""
parsed_args = parse_args(args)
config = resolve_config(parsed_args)
# Import mcp here to avoid import-time side effects
# This ensures logging is properly configured before server starts
from mcp_test_mcp.server import mcp
transport = config["transport"]
if transport == "stdio":
# STDIO transport - default for Claude Desktop/Code
mcp.run()
elif transport == "streamable-http":
# Streamable HTTP transport - FastMCP uses "http" internally
mcp.run(transport="http", host=config["host"], port=config["port"])
elif transport == "sse":
# Legacy SSE transport
mcp.run(transport="sse", host=config["host"], port=config["port"])
if __name__ == "__main__":
main()
