ACP Custom Extension Authoring

Before writing code

Fetch live docs:

1. Web-search site:github.com agentic-commerce-protocol rfcs extensions for the extensions framework RFC
2. Web-search site:github.com agentic-commerce-protocol examples for extension examples
3. Fetch https://developers.openai.com/commerce/specs/checkout/ for how extensions integrate with checkout
4. Study the built-in discount extension as a reference: web-search site:github.com agentic-commerce-protocol rfcs discount_extension

Conceptual Architecture

What Extensions Are

Extensions are composable, optional add-ons that augment ACP's core capabilities. They allow the protocol to grow without bloating the core spec — new features are added as extensions with independent lifecycles.

Extension Properties