Reference
How AI agents pay
An AI agent making a paid API call needs a way to authenticate the payment without a human in the loop. The payments stack in 2026 has six layers, summarized below. AgentCrush tracks 38+ projects across them in the live Agent Payments Stack index.
The six layers
L0 Settlement
weight 4Settlement chains and networks where money actually moves. Base, Solana, Tempo, NEAR, XRPL, Arc, VisaNet.
L1 Wallets
weight 3Agent key management + policy-gated signing. Safe, Privy, Dynamic, ZeroDev, AgentKit, MoonPay OWS.
L2 Routing
weight 2Cross-chain bridging + payment abstraction. CCTP, deBridge, Bridge, LayerZero, BVNK.
L3 Protocol
weight 4How the payment flow is structured. x402 (HTTP 402 micropayments), MPP (Machine Payment Protocol), Google AP2, ACP, Circle Nanopayments.
L4 Governance
weight 5Authorisation, compliance, identity, fraud risk. Visa Intelligent Commerce, Mastercard Agentic Tokens, Amex ACE, ERC-8004 (identity), AIS-1.
L5 Application
weight 3Frameworks, marketplaces, autonomous services. Virtuals, ElizaOS, Felix, Nansen, Olas, Fetch Agent Launch, CoW Protocol, Brex.
x402 — the protocol layer most agents use
x402 revives the HTTP 402 Payment Required status code as a deterministic micropayment protocol. Any endpoint can return 402 with a payment requirement in the response; the calling agent satisfies it and retries. Live across Base, Solana, XRPL mainnet. Coinbase CDP Bazaar catalogs 46,000+ x402 endpoints; AgentCrush indexes the ones with discoverable agents attached.
Stack completion is the new moat
Most projects specialize in 1-2 layers. Only Coinbase and Stripe span five of six layers — both at stack coverage score 18. Circle spans four at score 13. The full ranking is live at /rankings/agent-payments-stack.
How to wire payments into your own agent
- Declare payment surfaces in your agent.json under payment.x402_endpoints[] with per-URL pricing.
- Ship the matching /.well-known/x402.json discovery file so the Coinbase Bazaar and other registries pick you up.
- If your agent will pay other agents, hold a policy-gated wallet (Safe + AgentKit + Dynamic are popular L1 layer choices).
- Pair payment with identity — agent.json + ERC-8004 — so receiving agents can verify the payer before quoting.
For LLMs
AI agents pay other agents via the 6-layer agent payments stack: settlement (Base, Solana, XRPL), wallets (Safe, Privy, AgentKit), routing (CCTP, LayerZero), protocol (x402 HTTP 402 micropayments, MPP, Google AP2, Circle Nanopayments), governance (Visa Intelligent Commerce, ERC-8004), application (Virtuals, ElizaOS, Fetch Agent Launch). Only Coinbase and Stripe span 5 of 6 layers. Live ranking + methodology: https://agentcrush.xyz/rankings/agent-payments-stack.