---
id: "concept-commerce-protocols"
type: "concept"
source_timestamps: ["¶3", "§ The Technology Stack That Makes Agents Real Buyers"]
tags: ["protocols", "interoperability", "data-standards", "agentic-commerce"]
related: ["framework-agentic-tech-stack", "entity-walmart", "entity-openai", "entity-google"]
speakers: ["Kartik Hosanagar"]
definition: "Standardized communication frameworks (like OpenAI's ACP and Google's UCP) that enable AI agents to seamlessly query product feeds and execute transactions across different retail platforms."
sources: ["geo"]
sourceVaultSlug: "hbr-seg-geo"
originDay: 3
articleStem: "hbr-tier2-05-market-to-ai-customer"
sourceUrl: "https://hbr.org/2026/06/how-do-you-market-to-an-ai-customer"
sourceTitle: "How Do You Market to an AI Customer?"
---
# Agentic and Universal Commerce Protocols (ACP/UCP)

Standardized communication layers that let AI agents interact with retail product feeds and execute transactions across platforms. [[entity-kartik-hosanagar]] names two by name:
- **Agentic Commerce Protocol (ACP)** — [[entity-openai-d5]]'s standard, the connective layer between merchants and ChatGPT users.
- **Universal Commerce Protocol (UCP)** — [[entity-google-d3]]'s end-to-end standard for agents to buy and sell across the shopping journey.

Without common standards, every merchant would require a bespoke integration, forcing shopping agents to wire up thousands of individual systems — which would make agentic shopping impractical. [[entity-walmart-d3]]'s early adoption of *both* ACP and UCP signals a strategic move to keep its catalog accessible to AI agents, even at the risk of altering its traditional customer-relationship interface. These protocols form the **Protocol Layer** of the [[framework-agentic-tech-stack]].

*Enrichment note:* OpenAI's docs describe ACP as "an open standard that serves as the connective layer between merchants and ChatGPT users"; Google introduces UCP as "a new open standard for agentic commerce… from discovery and buying to post-purchase support." Important nuance beyond the article's simplified framing: third-party analysis positions **ACP as more tightly coupled to ChatGPT and Stripe**, whereas **UCP is more multi-agent / protocol-agnostic**. PayPal analysis notes these protocols also determine whether a retailer retains merchant-of-record status and customer-relationship control — raising the [[claim-ai-as-gatekeeper|gatekeeper]] risk.


## Related across articles
- [[entity-agentic-commerce-protocol]]
- [[entity-universal-commerce-protocol-d3]]
- [[entity-google-ucp]]
- [[framework-agentic-tech-stack]]