An agent payment is only finished when it settles on-chain. The ecosystem has converged on a few networks: Base (Coinbase’s L2, the home network of x402), Solana (sub-second finality for high-frequency micropayments), and the broader EVM family — with USDC as the de-facto unit of account across all of them.
These categories group the directory by settlement network, so you can shortlist tooling that works where your users already hold funds. Most x402 projects are chain-agnostic, but facilitators, wallets and examples usually target one network first.
