PAP vs ACP: Personal Agent Protocol vs OpenAI’s ACP
ACP solves paying. PAP solves getting in the door. The odd detail: Bret Taylor, who leads PAP at Sierra, chairs OpenAI’s board, and OpenAI still isn’t part of PAP.
| PAP | ACP | |
|---|---|---|
| Question it answers | May this agent act on this account? | How does the agent pay without seeing the card? |
| Created by | Sierra and Meta | OpenAI and Stripe |
| Spec status | Not published | Published |
| Payments | Future extension | Core: shared payment token |
| In production | No reported deployments | ChatGPT Instant Checkout |
| First public | Oct 6, 2026 | Sep 29, 2025 |
What each one does
Stripe and OpenAI released ACP on September 29, 2025. It powers Instant Checkout in ChatGPT. The key piece is a shared payment token, scoped to one merchant and one amount, so the agent can pay without ever holding the card number.
PAP doesn’t do payments yet. Its announced v0.1 model is an OAuth session with read-only or write access. "Payments extensions could let a personal agent complete a purchase without sharing credit card information," Sierra wrote, which reads a lot like what ACP’s token already does.
Where they meet
Stripe is the bridge. It co-wrote ACP and is a PAP launch partner. Its head of payments, Kevin Miller, said Stripe is contributing so businesses get "a standard way to recognize their customers’ agents".
Taylor told CNBC he’d be "really disappointed" if competitors didn’t use PAP. Whether that means OpenAI joins, or PAP’s payment extension leans on ACP-style tokens, is open.
Quick answers
Is OpenAI part of PAP?
No, as of October 8, 2026. Bret Taylor said he expects OpenAI and Anthropic to take part eventually.
Does PAP use Stripe’s shared payment tokens?
Nothing published says so. Payments are a future PAP extension with no details yet.
Can a business support both ACP and PAP?
Nothing in either announcement prevents it. They cover different steps of the same purchase.
Other comparisons
- All agent protocols in one table
- PAP vs MCP (Model Context Protocol)
- PAP vs A2A (Agent2Agent)
- PAP vs UCP (Universal Commerce Protocol)
- PAP vs TAP (Trusted Agent Protocol)
- PAP vs PACT (Personal Agent Consent & Trust Protocol)
Sources
- Introducing Personal Agent Protocol · Sierra (Bret Taylor, Clay Bavor), Oct 6, 2026 · primary source
- Stripe powers Instant Checkout in ChatGPT and releases Agentic Commerce Protocol codeveloped with OpenAI · Stripe, Sep 29, 2025 · primary source
- Meta joins with group of companies to tame 'chaos' of doing business with AI bots · CNBC, Oct 6, 2026
- Meta's Personal Agent Protocol Signs Walmart Before It Has a Spec · BERI
pap.md is independent and not affiliated with Sierra, Meta or any PAP partner. Facts here come from the sources listed on each page.