ACP sits between an agent's intent and a merchant's checkout chair, translating the messy world of identity, trust, and settlement into programmable APIs. Born from collaboration between OpenAI and Stripe, the Agentic Commerce Protocol aims to replicate the reliability of card networks without the brittle redirects or iframe gymnastics. Its thesis: when agents know exactly what proof of identity and funds a merchant expects, both sides can transact at human speed without human friction.
From handshake to checkout
A complete ACP session starts with the agent describing its purchase intent: who it represents, what it wants to buy, the price ceiling, and any policy context. The merchant replies with required credentials--perhaps a verifiable KYA claim, a payment capability token, or additional detail about the SKU. Facilitators broker this exchange, confirm funding sources, and return an authorization envelope that the agent can present to finalize the order. Each step is explicit, versioned, and traceable.
Three layers of ACP
For teams evaluating ACP, it helps to decompose the spec into three reinforcing layers.
- Identity envelopes: DIDs and verifiable credentials establish who the agent is acting for and what attestations back it.
- Policy checks: Structured requirements outline risk thresholds, shipping constraints, and consent prompts before money moves.
- Payment fulfilment: Rail-agnostic execution lets facilitators settle via cards, ACH, stablecoins, or marketplace balances.
Merchant integration path
On the merchant side, ACP integration feels like building a modern checkout API. You expose a discovery endpoint, define the credentials you accept, map items to agent-friendly descriptors, and plug in your payment service providers. Crucially, you can mix rails: tokenized cards, ACH, stablecoins, or marketplace balances. ACP does not dictate the settlement instrument; it standardizes how requirements are conveyed so facilitators like Agnic Pay can orchestrate the rails you already trust.
Why open matters
Openness is the differentiator. Proprietary agent programs risk locking merchants into single marketplaces or assistants. ACP's use of JSON schemas, DID methods, and open policy vocabularies makes the protocol portable. Merchants can support multiple assistant platforms with a single integration, and agents can roam without re-onboarding each store. That interoperability unlocks competition around service quality rather than gatekeeping.
What ACP unlocks next
The next stage is richer metadata: delivery commitments for physical goods, traceable carbon disclosures, or post-purchase service hooks. Because ACP is extensible, industries can define sector-specific modules without fragmenting the base spec. Expect to see consortiums publish schemas for digital media, SaaS seats, or travel inventory. The more merchants lean into ACP's structured negotiation, the more confidently they can let autonomous agents keep the checkout lights on.