🦾 Agentic Commerce

Shared Payment Token (SPT)

spt · shared payment token · delegated payment token · stripe shared payment token · delegated payments spec · agent payment token

Definition

A Shared Payment Token is Stripe's single-use payment token in the ACP protocol, which an AI agent uses to initiate payment without access to the shopper's real payment credentials.

The problem SPT solves

When an AI agent — one built into ChatGPT, say, or a voice assistant — makes a purchase on a user’s
behalf, one question decides everything: how do you give the agent the ability to pay without giving
it real payment credentials?

The classic options are both bad. Either the agent stores card data, which is a security risk, or
the user is sent back to a payment form by hand, which destroys the autonomy. The Shared Payment
Token is the compromise: the user authorises a token once, with defined limits, and the agent uses
it for one specific transaction.

How the mechanism works

1. The user authorises the AI application in Stripe
2. Stripe issues an SPT with constraints (amount, validity, category)
3. The AI agent passes the SPT to the merchant through ACP
4. The merchant initiates the charge through the Stripe API
5. Neither the agent nor the merchant ever sees the card data

The token is single-use: once spent, it is void. If the transaction does not happen inside the
validity window, the token expires on its own.

SPT and adjacent concepts

Concept	Who controls it	Scope
SPT	Stripe	One transaction between agent and merchant
Payment Mandate	The user or the AI application	Pre-set limits across all of the agent’s operations
Delegated Payments Spec	Any PSP	The standard for non-Stripe providers

Status and adoption

As of 2025 the SPT is a relatively new primitive, introduced by Stripe together with Anthropic and
OpenAI as part of pushing the ACP protocol forward. Commercial adoption outside those companies’
ecosystems is still limited, and in markets where local payment service providers have not announced
ACP support the standard has little practical relevance yet. The broader idea of delegated payments,
however, will grow as agentic commerce spreads.

Frequently asked questions

How does an SPT differ from an ordinary payment token?

An ordinary payment token is tied to one specific merchant and stored in that merchant's system. An SPT is a cross-platform token created by Stripe and handed to the AI application; it is valid for a single transaction and can be used in any store connected to ACP through Stripe.

What happens if the merchant does not use Stripe?

Stripe published the Delegated Payments Spec, an open specification that lets any payment processor implement an equivalent delegated payment mechanism. Merchants outside Stripe can join through a PSP that supports that specification.

Who controls the limits and permissions when an SPT is used?

The shopper sets the limits on the side of the AI application or the payment provider. This is close to the payment mandate concept — pre-set constraints such as a maximum amount, a product category and a validity window, inside which the agent can act autonomously.