ACP vs UCP
Last verified 2026-06-10Short answer: ACP and UCP are two agentic commerce standards attached to major agent surfaces. ACP, the Agentic Commerce Protocol (OpenAI and Stripe, 29 September 2025), powered the original Instant Checkout in ChatGPT; on 24 March 2026 OpenAI announced a focus on product discovery and merchant checkout; current purchases complete on the merchant side or inside a ChatGPT app. UCP, the Universal Commerce Protocol (launched by Google on 11 January 2026 and co-developed with Shopify, Etsy, Wayfair, Target and Walmart), is broader: it standardizes the full shopping journey, from discovery and checkout to post-purchase support. At launch, Google said UCP would soon power checkout on AI Mode and the Gemini app, with the retailer remaining seller of record. Both are open source under Apache 2.0, both are MCP-compatible, and a merchant can support both.
| Criterion | ACP | UCP |
|---|---|---|
| Author / steward | OpenAI and Stripe | Google and Shopify (+ Etsy, Wayfair, Target, Walmart) |
| Announced | 29 Sep 2025 | 11 Jan 2026 |
| Open-source status | Open source, Apache 2.0 | Open source, Apache 2.0 |
| What it is | Agent checkout / commerce protocol | Full-journey agentic commerce standard |
| Scope | Completing a purchase between buyer, agent and merchant | Discovery, checkout and post-purchase support |
| Payment type | Card and existing processors (Stripe SPT) | Payment Token Exchange; Google Pay at launch (PayPal announced) |
| Transport | HTTP (OpenAPI); MCP since 2026-04-17 | Transport-agnostic: REST, MCP or A2A |
| Primary surface | Product discovery in ChatGPT (Instant Checkout retired Mar 2026) | Google AI Mode and the Gemini app |
| Merchant position | Merchant remains merchant of record | Retailer remains seller of record |
| Notable adoption | OpenAI, Stripe, Etsy, Shopify (coming) | Google, Shopify, Etsy, Wayfair, Target, Walmart; 20+ endorsers |
Table last verified .