backward-compatible-frozen-extension

What problem does it solve?

You need to extend a frozen dataclass or Pydantic model without changing the existing interface or breaking downstream code, preserving backward compatibility.

Core Features & Use Cases

• Optional new fields with defaults to maintain compatibility, enabling richer data without modifying existing constructors.
• Parallel paths: old code paths and new, extended data paths can co-exist.
• Branching orchestrator logic to selectively utilize new fields when available.

Quick Start

Add a new optional field with a default to a frozen dataclass or Pydantic model and adjust the constructors to remain backward-compatible.