I Built a Validator for a Protocol That Didn't Exist 8 Weeks Ago

In January 2026, Google and Shopify announced the Universal Commerce Protocol (UCP) at NRF - an open standard that lets AI agents like ChatGPT, Gemini, and Copilot discover products, browse catalogs, and complete purchases on e-commerce stores. Within hours, I knew there'd be a tooling gap. Merchants would need to validate their UCP profiles. Developers would need to test their implementations. And nobody was building it yet. So I did. Here's what 8 weeks of building on an emerging standard actually looks like. Week 1: Racing the Spec The UCP spec was published alongside the announcement. I read the whole thing that weekend. The core concept is elegant: serve a JSON manifest at /.well-known/ucp that tells AI agents what your store can do. { "version" : "2026-01-11" , "capabilities" : [ { "name" : "checkout" , "version" : "1.0" } ], "payment_handlers" : [ { "type" : "stripe" } ] } The first validator was 200 lines of TypeScript. Parse JSON, check required fields, validate URLs. Ship it.