Evergreen Tools
|
← Back to AI Tools

AI Agent Payments

Let AI agents actually pay on your behalf: AP2, ACP, x402 and MPP turn authorisation, checkout and settlement into signed, auditable machine flows — the payment layer of 2026 agentic commerce

Tool Interface

Interactive tool will be available soon

Features

  • ✓ Turns user consent into verifiable signed credentials — Intent, Cart and Payment Mandates — so an agent can only spend within its mandate
  • ✓ Covers both rails: card-network agent tokens from Visa and Mastercard, plus x402 HTTP-native micropayments
  • ✓ Works with MCP and A2A so agents can pay per call while invoking tools and data sources
  • ✓ Enforces spend limits, merchant allowlists and human-confirmation thresholds, falling back to approval instead of hard failing
  • ✓ Leaves a fully auditable trail per transaction for reconciliation, fraud control, refunds and disputes

How to Use

  1. Pick your role first — Merchant Agent (machine-readable pricing), User Agent (pays on behalf of a user) or Payment Rail (settlement) — the integration point differs entirely
  2. Then pick protocols: AP2 and ACP for card and commerce flows, x402 and MPP for machine-to-machine and API micropayments. They are complementary, not mutually exclusive
  3. Run the full loop in sandbox — authorise, checkout, settle, refund, reconcile — and stress-test idempotency, timeouts and double charges
  4. Before launch, wire limits, allowlists, human confirmation and reconciliation alerts into your existing risk stack, and keep per-transaction mandate records for disputes

FAQ

What are AI agent payments?

A class of protocols and services that let AI agents complete payments on behalf of a user or an organisation. The hard problem is not calling a payments API — it is proving what an agent is allowed to spend, how much, and that the user actually consented. The core pattern is to encode consent as a signed mandate that constrains both the scope and the ceiling of the transaction, with every step verifiable and auditable.

Which agent payment protocols exist today?

Four main lines: Google's AP2 (Agent Payments Protocol), which uses signed Intent, Cart and Payment Mandates and launched with 60+ partners including Mastercard, PayPal and Coinbase; Stripe and OpenAI's ACP (Agentic Commerce Protocol), open-sourced under Apache 2.0 and live in ChatGPT Instant Checkout; Coinbase's x402 for HTTP-native micropayments between machines and APIs; and MPP (Machine Payments Protocol) from Stripe and Tempo, launched 18 March 2026, whose sessions model pre-authorises a spend limit. See the protocol tracker at https://agenticplug.ai/current-state-of-agentic-commerce and the comparison at https://www.crossmint.com/learn/agentic-payments-protocols-compared

Is it safe to let an agent spend money?

Safety comes from the mandate, not from trusting the model. AP2's central idea is that authorisation is a signed mandate — an agent acting outside it fails verification. In practice you stack four controls: per-transaction and periodic spend caps, merchant and category allowlists, mandatory human confirmation above a threshold, and per-transaction mandate records for reconciliation and disputes. Critically, isolate payments from the content the agent reads: a prompt-injected page must never be able to trigger a charge. Protocol details at https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol

x402 vs AP2 vs ACP vs MPP — which should I use?

Decide by what is being paid for. Buying physical or digital goods through card and commerce settlement points to AP2 or ACP. Having an agent pay per call for APIs, data feeds or compute fits x402, because it is HTTP-native and the server expresses price in the response. Giving an agent a budget it streams over a period — subscriptions, continuous calls — maps to MPP's sessions model. Most enterprises will support several rails rather than betting on one.

How much do I have to change to integrate?

It depends on which side you are on. As a merchant, the minimum viable version is exposing machine-readable catalogue, price and stock, then validating mandates before settlement — no need to rewrite your payment stack. As a user-agent builder, the work is a standalone authorisation, limits and confirmation module wired to each protocol's SDK. Most protocols ship sandboxes and reference implementations; start with a single low-value real transaction, then raise limits gradually.

What should I watch on compliance and risk in 2026?

Three things. Provability: every agent payment must reconstruct who authorised it, within what scope and when — that is the basis for disputes and refunds. Identity: agents need their own rotatable credentials, never a reused long-lived human key. Data boundaries: pages and documents an agent reads are untrusted input and need injection defences, or one malicious page can induce an out-of-scope purchase. In regulated sectors, fold agent payments into existing AML and reconciliation processes.