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Factory System

The factory system provides a centralized, reflection-based approach to creating instances of both Target and ResponseGenerator from configuration.

Overview​

The new factory system is located in src/mcp_kit/factory.py and replaces the previous manual factory methods with a more generic, reflection-based approach.

Core Components​

create_object_from_config()​

The generic factory function that can create any object type from configuration using reflection.

Parameters:

  • config: Configuration object with a 'type' field
  • get_class_name: Function that converts type string to class name
  • get_module_name: Function that converts type string to module name
  • object_type_name: Name of object type for error messages

create_target_from_config()​

Factory function specifically for creating Target instances.

Example:

from src.mcp_kit.factory import create_target_from_config

config = {
    "type": "mcp",
    "name": "example-server",
    "url": "http://localhost:8080/mcp"
}
target = create_target_from_config(config)

create_response_generator_from_config()​

Factory function specifically for creating ResponseGenerator instances.

Example:

from src.mcp_kit.factory import create_response_generator_from_config

config = {
    "type": "llm",
    "model": "gpt-4"
}
generator = create_response_generator_from_config(config)

Naming Conventions​

Targets​

  • Configuration type: "mcp" → Class: McpTarget → Module: src.mcp_kit.targets.mcp_target
  • Configuration type: "oas" → Class: OasTarget → Module: src.mcp_kit.targets.oas_target
  • Configuration type: "mocked" → Class: MockedTarget → Module: src.mcp_kit.targets.mocked_target

Response Generators​

  • Configuration type: "random" → Class: RandomResponseGenerator → Module: src.mcp_kit.generators
  • Configuration type: "llm" → Class: LLMResponseGenerator → Module: src.mcp_kit.generators

Benefits​

  1. Eliminates Manual Factories: No need to manually update factory methods when adding new types
  2. Consistent Error Messages: Standardized error handling across all object types
  3. Type Safety: Proper type hints and runtime checking
  4. Extensibility: Easy to add new object types without modifying existing factory code
  5. Reduced Circular Imports: Centralized factory prevents circular import issues

Migration​

The refactoring maintains backward compatibility:

  • All existing from_config() methods continue to work
  • Import paths have been updated from src.mcp_kit.targets.factory to src.mcp_kit.factory
  • Error messages have been standardized but tests have been updated accordingly

Adding New Types​

To add a new target type:

  1. Create the class following the naming convention (e.g., NewTarget)
  2. Implement the from_config() class method
  3. Place it in the appropriate module (e.g., src.mcp_kit.targets.new_target)
  4. The factory will automatically discover and instantiate it

To add a new generator type:

  1. Create the class following the naming convention (e.g., NewResponseGenerator)
  2. Implement the from_config() class method
  3. Place it in src.mcp_kit.generators
  4. The factory will automatically discover and instantiate it