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ProxyMCP Configuration System

This document describes how to use the ProxyMCP.from_config() factory method to create ProxyMCP instances from configuration files.

Overview​

The configuration system uses a clean, modular architecture where each object type is responsible for creating itself from configuration. The factory method supports creating instances with any type currently supported in src/mcp_kit/:

Architecture​

This design follows the single responsibility principle, where each target is responsible for understanding its own configuration format.

Configuration Format​

Configuration files support both standard YAML or JSON formats.

Using Target Factory Methods Directly​

You can also create targets directly using their individual factory methods:

from omegaconf import OmegaConf
from src.mcp_kit.factory import create_target_from_config

# Create targets directly
config = OmegaConf.load("config.yaml")

# Direct target creation
target = create_target_from_config(config.target)

# Then wrap in ProxyMCP
proxy = ProxyMCP(mcp_target)

Example Configuration Files​

Example configuration files are available in examples/proxy_configs/:

  • mcp_target.yaml - Simple MCP target
  • oas_target.yaml - OpenAPI specification target
  • mocked_random_target.yaml - Mocked target with random responses
  • mocked_llm_target.yaml - Mocked target with LLM responses
  • multiplex_target.yaml - Multiplex target combining multiple servers
  • mcp_target.json - JSON format example

Error Handling​

The factory method will raise ValueError for:

  • Unknown target types
  • Unknown response generator types
  • Missing required configuration fields

Testing​

Unit tests are available for both the high-level ProxyMCP factory and individual target factories:

ProxyMCP factory tests:

uv run pytest tests/test_proxy_config.py::TestProxyMCPFromConfig -v

Individual target factory tests:

uv run pytest tests/test_target_from_config.py::TestTargetFromConfig -v

Run all configuration tests:

uv run pytest tests/test_proxy_config.py tests/test_target_from_config.py -v

The test suite covers:

  • All target types and their factory methods
  • Error handling for invalid configurations
  • Nested target configurations (e.g., mocked targets with mocked base targets)
  • Both YAML and JSON configuration formats
  • Edge cases like minimal configurations and default values

Future Enhancements​

The configuration system is designed to be easily extensible for future features like:

  • Multiple proxy instances from a single configuration file
  • Environment variable substitution
  • Configuration validation schemas
  • Dynamic configuration reloading