Where does your agent's money actually move, and how does it go wrong there?

Base is an OP Stack L2 with about 200ms blocks and cheap fees, so an agent can pay fast, but the L1 data fee and the bridged-versus-native USDC split still need checking.

Ethereum mainnet is the settlement layer: expensive, but with a clear finalized tag that tells an agent when a payment is final.

Arbitrum One is an optimistic rollup with a sequencer feed for soft confirmation and a long challenge period before withdrawals reach Ethereum.

OP Mainnet is the flagship OP Stack L2, where an agent pays an L1 data fee on top of gas and relies on L1 forced inclusion if the sequencer stalls.

Polygon PoS finalizes through milestones in about 2 to 5 seconds since Heimdall v2; it had a 157-block reorg in February 2023, before milestone finality, and a milestone delay in September 2025, so agents should use the finalized tag.

Avalanche C-Chain accepts transactions with irreversible finality in about a second, with AVAX gas and a native-USDC and native-USDT split from bridged tokens.

Linea is a zk rollup with about 1 second soft finality but a median of about 2 hours to hard finality, which decides when withdrawals and exchange deposits clear.

Solana is a high-throughput L1 where an agent pays in SPL tokens through per-wallet token accounts, using short-lived blockhashes and a choice of commitment level.

Tron is where Tether issues USDT as a TRC-20 token, and an agent must manage bandwidth and energy or the transfer burns TRX or fails.

Lightning settles Bitcoin payments off-chain through invoices, where the preimage is the receipt and expiry, routing and liquidity are the failure points.

Sui finalizes transactions in well under a second and uses a native Circle USDC coin type, but gas budgets and CCTP timing still shape agent flows.

USDC is Circle's stablecoin, issued natively on dozens of networks and moved between them by CCTP burn and mint, with Circle able to block addresses.

USDT is Tether's stablecoin, live on a fixed list of chains, with some chains deprecated and Tether holding freeze and blacklist powers.

An HTTP 402 payment protocol where an agent signs a payment authorization, retries the request, and a facilitator verifies and settles it on chain.

Stripe's agent payment stack: Shared Payment Tokens for cards, the Agentic Commerce Protocol for checkout, and machine payments (MPP and x402) for pay-per-call stablecoin and card payments.

A toolkit that gives an AI agent a wallet and onchain actions, backed by CDP server wallets with a policy engine and an optional Base paymaster for gas.

An open protocol that uses signed, chained mandates to prove what a user authorized an agent to buy and to pay.

Smart contract accounts that run UserOperations through a bundler and paymaster, with delegated permissions (ERC-7715, ERC-7710) used to give an agent a scoped, expiring spending key.