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Overview

A facilitator is a payment settlement server that acts as an intermediary between resource servers (APIs) and clients in the x402 payment protocol. It handles the blockchain-specific logic for validating and executing payments, allowing resource servers to remain payment-agnostic.

Try a facilitator

Use the Corbits facilitator: https://facilitator.corbits.dev

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Why Facilitators Exist

Facilitators solve several critical problems in the x402 payment protocol:

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1. Abstract Blockchain Complexity

Resource servers (your APIs) don’t need to understand blockchain-specific details like:
  • Transaction formats and signing
  • Gas fee management
  • Network-specific parameters (blockhashes, chain IDs, EIP-712 domains)
  • Token contract interfaces

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2. Handle Gas Payments

The facilitator sponsors transaction fees on behalf of clients:
  • Solana: Acts as the fee payer, co-signing transactions to pay network fees
  • EVM: Pays gas costs for executing transferWithAuthorization using EIP-3009

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3. Validate Payment Proofs

Before settling on-chain, the facilitator performs extensive validation:
  • Verifies payment amounts match requirements
  • Checks signatures and authorization validity
  • Prevents clients from attempting to steal facilitator funds
  • Validates transaction parameters (compute limits, priority fees, etc.)

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4. Enable Multi-Chain Payments

A single facilitator can support multiple blockchains and payment methods simultaneously through a pluggable handler architecture.

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The Role in x402

In the x402 payment protocol, the facilitator sits between three parties:
  1. Resource Server (Merchant) - Hosts protected content/APIs
  2. Facilitator - Validates and executes payments
  3. Client (User) - Pays to access resources
The resource server never handles blockchain transactions directly. Instead, it delegates all payment logic to the facilitator, keeping the merchant’s infrastructure simple and blockchain-agnostic.