Openclaw Research · March 2026

Agentic Payment Protocols

The complete landscape of how AI agents move money — protocols, wallets, identity layers, and settlement rails.

Major Protocols

140M+

Total Txns

60+

Partner Orgs

$3-5T

2030 TAM Est.

x402

Production

Coinbase + Cloudflare → x402 Foundation

Revives HTTP 402 "Payment Required" for instant stablecoin payments. The settlement layer — no accounts, no API keys, no checkout flows. One HTTP round-trip: request → 402 → pay → resource.

Txn Volume

119M+ (Base alone)

Settlement

USDC on Base, Solana, Stellar

Latency

~400ms (Solana), ~2s (Base)

Tx Cost

$0.00025 – $0.01

V2 (Dec 2025)

Sessions, multi-chain, discovery

Backers

Google, Visa, Vercel, Cloudflare

MPP

New · Mar 2026

Stripe + Tempo (Paradigm) · Visa design partner

Machine Payments Protocol. "OAuth for payments" — agents authorize once via a session, then stream micropayments. Dual-rail: stablecoins on Tempo chain + fiat via Stripe (cards, BNPL, SPTs).

Session Model

Pre-fund → stream payments

Settlement

Tempo L1 (USDC) + Stripe fiat

Fiat Support

Cards, wallets, BNPL via SPT

Extensions

Visa cards, Lightning (Lightspark)

SDK

mppx/server (Node.js)

Status

Mainnet live, early access

AP2

Early Adoption

Google Cloud · 60+ partners incl. Mastercard, PayPal, Amex

Agent Payments Protocol. The trust & authorization layer — cryptographically signed Mandates (Intent, Cart, Payment) using W3C Verifiable Credentials. Extends A2A protocol.

Core Primitive

Mandate (ECDSA-signed JSON-LD)

Mandate Types

Intent / Cart / Payment

Crypto Ext.

A2A x402 extension

Fiat Support

Card networks via partners

Identity

W3C Verifiable Credentials

Consumer Product

None yet

ACP

Pivoting

OpenAI + Stripe · Apache 2.0

Agentic Commerce Protocol. Standardizes checkout flows between AI agents and merchants. Merchant remains MoR. Uses Shared Payment Tokens — agents never see raw card data.

Focus

E-commerce checkout

Settlement

Fiat via Stripe infra

Security

Scoped Payment Tokens (SPT)

Buyer Model

Human always present

Platform

ChatGPT → app-based model

Fee

4% per transaction

KYAPay / Skyfire

Production

Skyfire · a16z CSS + Coinbase Ventures

Identity + payments network for agents. KYA (Know Your Agent) protocol: JWT-based agent identity verification, OAuth2/OIDC compatible. Bridges crypto micropayments with Visa card rails.

Identity

KYA JWT tokens (agent + human)

Payment Tokens

PAY / KYA+PAY combo JWTs

Funding

CC, ACH, Wire, USDC

Visa Integration

Intelligent Commerce demo

Guardrails

JIT decisioning, spend limits

Partners

F5, Visa, Cequence, Tars

Dimension	x402 ●	MPP ●	AP2 ●	ACP ●	KYAPay ●
Primary Layer	Settlement (HTTP-native)	Settlement + Sessions	Authorization & Trust	Checkout Flow	Identity + Payments
Backed By	Coinbase, Cloudflare, Google, Visa	Stripe, Tempo/Paradigm, Visa	Google + 60 partners	OpenAI + Stripe	Skyfire (a16z, CB Ventures)
HTTP Mechanism	402 challenge→pay→retry	402 challenge→session→stream	Mandate signing (A2A ext.)	Checkout API / SPT flow	JWT auth + PAY token
Crypto Settlement	✓ Native Base Solana Stellar	✓ Native Tempo	✓ via x402 ext.	✗ Fiat only	✓ USDC
Fiat Support	Deferred (planned)	✓ Cards, BNPL, wallets	✓ Full card network	✓ Stripe native	✓ CC, ACH, Wire
Agent Identity	ERC-8004 (emerging)	None built-in	W3C VCs, Mandates	Scoped tokens only	KYA protocol (full)
Micropayments	Designed for it	Session streaming	Not core focus	Not supported	<$5 native
Agent-to-Agent	Native A2A payments	Agent sessions	A2A protocol ext.	Human must be present	Agent marketplace
MCP Integration	x402-MCP server	Via Stripe MCP	MCP extension	Via Stripe MCP	MCP-compatible
Wallet Infra	Coinbase Agentic Wallets (TEE)	Privy / Stripe wallets	MetaMask, Crossmint	N/A (Stripe handles)	Skyfire managed wallets
Spend Guardrails	Wallet-level limits	Session pre-auth limits	Mandate conditions	Merchant accept/reject	JIT decisioning + SMS
Open Source	Yes	Yes	Yes (spec)	Apache 2.0	KYA protocol open
Production Traction	★★★★★ 140M+ txns	★★★☆☆ Week 1	★★☆☆☆ No product	★★☆☆☆ Pivoted	★★★★☆ Visa+F5
Best For	API micropayments, M2M, crawl fees	Dual-rail fiat+crypto	Enterprise trust, audit trails	E-commerce checkout	Agent identity + shopping

The Agentic Payments Stack

These protocols aren't competitors — they're layers. A complete system uses multiple.

Agent Identity

Who is this agent? Who authorized it?

KYA / KYAPayAP2 MandatesVisa TAPERC-8004MC Agentic Tokens

Authorization

What can this agent spend?

AP2 Intent MandatesMPP Sessionsx402 Wallet LimitsSkyfire JITACP SPTs

Commerce / Checkout

Cart, catalog, merchant interaction

ACP (OpenAI)Shopify UCPA2A ProtocolAgent CheckoutMCP (Anthropic)

Payment Protocol

How payment flows between agents

x402 (HTTP 402)MPP (HTTP 402)ATP (Circuit & Chisel)KYAPay JWTs

Wallet Infra

Agent-owned wallets, key mgmt

Coinbase AgentKitPrivyCrossmintTurnkeyThirdwebSafeZeroDev

Settlement Rails

Where value actually moves

Base (119M txns)Solana (38.6M)Tempo L1EthereumStellarVisa/MC railsLightning

Monetary Base

What agents transact in

USDC (98.6% of agent txns)USDTPATH USD (Tempo)Fiat (USD/EUR)

Openclaw Verdict: What to Build With

Practical recommendations for an AI trading bot arena platform

For Openclaw Bot Arena

x402 + Coinbase Agentic Wallets

Primary choice. Every bot in the arena needs a wallet. Coinbase Agentic Wallets provide TEE-secured non-custodial wallets with built-in OFAC compliance. x402 handles all M2M payments — bots paying for data feeds, compute, other bots' signals. 140M+ txns prove it works at scale. USDC on Base gives you sub-second finality at near-zero cost.

For Fiat On/Off Ramp

MPP as secondary rail

Watch closely. MPP's session model is elegant — agents pre-authorize a budget, then stream micropayments without per-txn overhead. The Stripe integration means users can fund arena participation with credit cards. Tempo is 10 days old but Stripe's distribution is unmatched.

For Trust / Enterprise

AP2 Mandates for high-stakes

Not yet, but monitor. When Openclaw runs institutional competitions, AP2's cryptographic mandates give you the audit trail compliance teams need. The Intent Mandate pattern — "buy up to $X if condition Y" — maps perfectly to bounded agent strategy authorization.

For Agent Identity

KYA + on-chain reputation

Combine Skyfire's KYA with ERC-8004. In a bot arena, identity = reputation. KYA JWTs give agents verifiable identity linked to their human operators. ERC-8004 gives on-chain agent registries. Together: every bot has a provable track record and trust score.

Skip for Now

ACP (OpenAI/Stripe)

Wrong fit. ACP is built for human-present e-commerce checkout. Openclaw is agent-autonomous M2M. ACP requires a human in the loop, charges 4%, and OpenAI already pivoted away from its flagship implementation.

Architecture Pattern

The Winning Stack

Layer it: KYA for identity → x402 for settlement → Coinbase Agentic Wallets for key management → Base for on-chain → AP2 mandates when you go enterprise. USDC is the unit of account — 98.6% of agent payments already settle in Circle stablecoins.