Card networks, bank rails, real-time payments, and on-chain transfers — compared for agent use cases. No single rail wins everywhere.
Layer 7 is the physical infrastructure of payment: the moment value actually changes hands. For agents, the ideal rail is programmable, cheap, fast, and globally accessible — none of today's rails check all four boxes.
At a glance
| Rail | Network | Token / Currency | Finality | Typical Fee | Agent-Native? | Status |
|---|---|---|---|---|---|---|
★ x402 |
Base (EVM) | Any ERC-20 | ~2s | <$0.001 | Yes | Live |
Lightning |
Bitcoin L2 | BTC (sats) | Instant | ~0 | Partial | Live |
Solana Pay |
Solana | Any SPL token | <1s | ~$0.00025 | Partial | Live |
Stripe / Card |
Visa / Mastercard | 135+ currencies | 2-3 days settle | 2.9% + $0.30 | Via toolkit | Traditional |
FedNow / RTP |
US Bank Network | USD | Seconds | <$1 | No | New (2023) |
NEAR Intents |
NEAR / Cross-chain | Any token | <2s | Near-zero | Yes | Emerging |
Protocol Deep Dives
The most agent-native rail today. An agent calls the ExactProxy or UptoProxy contract, which executes an ERC-3009 signed transfer — payer → payee in a single transaction. No account creation, no OAuth, no invoice. Any ERC-20 token works.
Bitcoin's Layer 2 for instant micropayments. Agents open payment channels once and send unlimited off-chain payments at near-zero cost. BOLT12 (the modern spec) adds reusable "offers" — a URL an agent can pay repeatedly, ideal for recurring service billing.
Open protocol for payments over the Solana network. Agents pay any SPL token (USDC, SOL) with sub-second finality and ~$0.00025 per transaction. Transaction requests are structured as URLs — easy to embed in API responses for machine consumption.
Stripe's official SDK for AI agents — wraps card-network payments as LLM-callable tools. Agents create payment intents, manage subscriptions, and list invoices via function calling. No crypto wallet needed, works in 135+ currencies. Best for B2B SaaS and subscription billing.
US real-time bank rails. FedNow (Federal Reserve, launched 2023) and RTP (The Clearing House) enable instant USD transfers between bank accounts 24/7. Not designed for agents, but Modern Treasury and similar companies provide API wrappers that agents can call.
Chain-abstracted payment intents — an agent declares "pay X in token Y" and the protocol finds the optimal cross-chain route. No bridging UX, no slippage negotiation. Designed from the ground up for machine-initiated payments.
The Core Gap
No single rail is programmable, cheap, fast, and globally accessible. x402 wins on programmability and cost but is EVM-only. Lightning wins on cost but is Bitcoin-only. Stripe wins on global reach but is expensive and slow to settle. The agent economy will need multi-rail routing — agents that choose the optimal rail per transaction type, jurisdiction, and counterparty. That router doesn't exist yet.