Standards

The agent-native protocols companies in this registry implement. Each explainer is plain, and every standard lists the companies that tag it in an offering.

x402

Steward: x402

x402 is an HTTP-native payment protocol that uses the 402 Payment Required response to let clients, including AI agents, pay for APIs and digital resources before retrying a request.

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Agentic Commerce Protocol

Steward: OpenAI and Stripe

ACP is an open protocol for commerce flows among buyers, AI agents, and businesses, with a focus on checkout configuration, order control, payment credentials, and merchant of record relationships.

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Agent Payments Protocol

Steward: Google

AP2 is an open agent payments protocol that uses verifiable digital credentials and mandates to bind user intent, checkout details, and payment authorization for agent-led transactions.

No companies in the registry tag this standard yet.
Read the spec ↗

Know Your Agent

Steward: Ankit Agarwal, Craig DeWitt, David Senecal, and Michael B. Jones

KYA is a protocol for identifying an AI agent, the platform it runs on, and the user it represents, so online businesses can authenticate agent traffic and understand delegated intent.

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Machine Payments Protocol

Steward: Stripe

MPP is a machine-to-machine payment protocol for paid internet resources where a server returns an HTTP 402 response with payment details, the client authorizes payment, and the request is retried with proof.

No companies in the registry tag this standard yet.
Read the spec ↗

Trusted Agent Protocol

Steward: Visa

TAP is a proposed protocol for helping retailers distinguish legitimate AI shopping agents from malicious automation while supporting agentic commerce with existing merchant systems.

No companies in the registry tag this standard yet.