# Payments & Settlement

> how agents authorize and move value

_7 of 28 · [all The Agent Protocol Atlas](/protocols)_

- [x402](/protocols/payments/x402) — Revives the dormant HTTP 402 status code so an agent can pay for a resource inline — request, get 402 with terms, pay in stablecoin, retry.
- [AP2](/protocols/payments/ap2) — Payment-agnostic settlement inside the A2A task lifecycle — handles cards, bank transfers and crypto through one mandate-based framework.
- [ACP (Agentic Commerce)](/protocols/payments/acp-commerce) — Lets an agent complete a purchase inside the conversation — the checkout that powers ChatGPT's Instant Checkout.
- [UCP](/protocols/payments/ucp) — An open standard for interoperability between commerce entities so AI agents can discover products, fill carts, and complete purchases — orchestrating A2A, AP2 and MCP across the commerce journey.
- [MPP](/protocols/payments/mpp) — Stripe and Tempo's open standard for billing AI agents over HTTP — agents discover prices, pay, subscribe and reconcile across stablecoins, cards and BNPL, with cryptographic receipts.
- [Kite](/protocols/payments/kite) — A payments-and-identity layer for the agent economy: verifiable agent identities (Agent Passport), cryptographically enforced spending constraints, and stablecoin rails, integrating x402, AP2 and MCP.
- [Visa TAP](/protocols/payments/visa-tap) — An open specification that signs an AI agent's identity into HTTP request headers so any merchant can cryptographically verify the agent is legitimate before agent-driven checkout.