> For the complete documentation index, see [llms.txt](/llms.txt).

# x402 Payments

[x402](https://www.x402.org/) is an open payment protocol that uses the HTTP `402` status code to enable programmatic, machine-to-machine payments over HTTP. It allows servers to charge for API access without requiring buyer accounts, API keys, or traditional payment infrastructure.

For example, an AI agent can pay 0.01 USDC per request to access a weather API, or a dapp can charge users a micro-payment to retrieve premium onchain analytics data.

## ERC-7710 payments[​](#erc-7710-payments "Direct link to ERC-7710 payments")

The standard x402 protocol supports direct token transfers (using ERC-20 Permit2 or EIP-3009). [ERC-7710](https://eips.ethereum.org/EIPS/eip-7710) extends this by enabling [delegation](/smart-accounts-kit/development/reference/glossary#delegation)**Delegation** The ability for a MetaMask smart account to authorize another account to perform specific executions on its behalf.-based payments from [MetaMask smart accounts](/smart-accounts-kit/development/reference/glossary#metamask-smart-account)**MetaMask smart account** A smart contract account created using the Smart Accounts Kit that supports programmable behavior, flexible signing options, and ERC-7710 delegations..

With ERC-7710, a buyer's smart account creates a delegation that authorizes the facilitator to transfer tokens on their behalf. The buyer doesn't sign a direct token approval. Instead, they sign a delegation that the facilitator redeems during settlement.

This approach enables buyers to pay from MetaMask wallet. Buyers can restrict delegations to specific facilitator addresses, amounts, and time windows using [delegation scopes](/smart-accounts-kit/development/reference/glossary#delegation-scope)**Delegation scope** A predefined authority pattern representing a caveat or group of caveats, which sets the initial actions a delegate is allowed to perform. You can combine scopes with additional caveats.. They can also create long lived delegations that allow recurring payments without re-signing for each request.

Learn more [ERC-7710 delegations](/smart-accounts-kit/concepts/delegation/overview/).

## Guides[​](#guides "Direct link to Guides")

Get started with x402 payments in Smart Accounts Kit. These guides walk you through seller endpoint setup and buyer payment flows.

- [Set up a seller endpointConfigure a resource server that returns x402 payment requirements and settles requests.](/smart-accounts-kit/development/guides/x402/seller/)
- [Pay using a delegationCreate an ERC-7710 delegation and use it as the x402 payment payload.](/smart-accounts-kit/development/guides/x402/buyer/delegations/)
- [Set up recurring paymentsGrant a periodic budget permission for recurring x402 payments.](/smart-accounts-kit/development/guides/x402/buyer/recurring-payments/)