@fidesbuild/x402

FIDES is a Transaction Builder for autonomous agents. It builds complete agent transaction flows across MCP, x402 and onchain actions, with authorization built into the execution path.

npm install @fidesbuild/x402 viem

import { createX402 } from "@fidesbuild/x402"

const x402 = createX402({ fides, payer: agent })
const res = await x402.fetch(url)   // answers a 402 by paying, if the FIDES allows it

Supports the exact scheme over EIP-3009 and Permit2, and x402 over MCP. A payment outside the service's cap or the FIDES's limit is refused before anything is signed. FIDES integrates x402 as it exists; it does not define its own payment standard.

Links

• Docs: https://fidesbuilder.xyz/docs
• Contract addresses: https://fidesbuilder.xyz/docs#/deployments
• App: https://fidesbuilder.xyz/app

MIT licensed.