The Agent Payments Stack

Last updated: March 25, 2026

How AI agents will move $600M this year

AI agents settled $43 million across 140 million transactions in just nine months. Every major payment network is now racing to build the rails. The week of March 17-23, 2026 alone saw Mastercard's $1.8B acquisition of BVNK, Stripe's Tempo mainnet launch, and MoonPay's Open Wallet Standard release.

This is no longer speculative infrastructure. 98.6% of agent payments settle in USDC, and annualized volume is approaching $600M.

The stack has six layers

The agent payments stack has crystallized into six distinct layers, each answering a different question in the payment flow:

• Settlement (L0) answers where transactions land. Base leads with 119M x402 transactions. Solana leads in dollar volume share. Everything else is positioning.
• Wallet and key management (L1) answers where keys live. The market has split into full-stack agent wallets (Coinbase, MoonPay OWS, Crossmint) and signing primitives (Turnkey, Lit, Safe). A wave of acquisitions (Stripe bought Privy, Fireblocks bought Dynamic, Arbitrum bought ZeroDev) is consolidating this layer fast.
• Routing and abstraction (L2) answers which chain, which token, which rail. The biggest trend: convergence of crypto and card rails through a single abstraction. Mastercard's $1.8B BVNK acquisition and Stripe's $1.1B Bridge acquisition are the clearest signals.
• Payment protocol (L3) answers how the payment flow works. Three paradigms are crystallizing: x402 (crypto-native HTTP payments), Tempo MPP (multi-rail sessions), and Google AP2 (payment-agnostic authorization). They are designed to interoperate.
• Governance and policy (L4) answers whether an agent may spend, and how much. The "Brex for agents" category has gone from concept to reality. Ramp and Brex now offer agent card products. Crypto-native alternatives like Skyfire and Sponge provide stablecoin-based controls.
• Application (L5) answers what gets bought and why. DeFi trading agents are the most mature category. Agent economy platforms (Virtuals, ElizaOS, Olas) are the most hyped. Services agents pay for (compute, data, creative assets) represent the longest tail.

Five companies are trying to own the whole stack

Coinbase is the most vertically integrated, controlling settlement (Base), wallets (AgentKit), protocol (x402), identity (ERC-8004), and onramp/offramp. Stripe matches that span through Tempo (settlement), Privy (wallets), MPP + ACP (protocol), Bridge (routing), and SPTs (governance). Circle controls the monetary base layer: 98.6% of agent payments settle in their stablecoin. Google plays the standards layer with AP2 and A2A. MoonPay bet on open standards with OWS.

Three bets shaping the stack

The first bet is settlement rails. Coinbase's x402 argues the future is crypto-native HTTP payments on Base and Solana. Stripe's MPP argues agents need multi-rail access settling on Tempo. These are not mutually exclusive, but they represent different visions of where value accrues.

The second bet is identity and authorization. Google's AP2 mandates, Visa's Trusted Agent Protocol, ERC-8004's on-chain registries, and Skyfire's KYA all compete to answer "should this agent be trusted to spend?" The winner captures the governance chokepoint.

The third bet is vertical versus horizontal. Coinbase and Stripe are building full stacks, while Skyfire, ATXP, and MoonPay bet that open standards and middleware layers will capture value between the giants.

The clearest near-term signal is consolidation. Five acquisitions exceeding $100M occurred in the past year. The convergence of traditional payments (Visa, Mastercard, Stripe) with crypto-native infrastructure (Coinbase, Circle, Cloudflare) is compressing timelines. The rails being laid today will determine who collects tolls on agentic commerce for the next decade.