How to turn a testnet x402 project into one on Base mainnet in 3 minutes

Product & onchain AI @ Coinbase, Founder @ Vanderbilt Blockchain, EPF Fellow and SSF Enthusiast

lincoln can you explain what the x402 facilitator does?

still have not read a coherent explanation

User hits backend with request

Backend says 402 payment required, send me X USDC

User constructs signature, signs it, then sends it back 

Facilitator, the middleware piece, picks it up and runs the verify/settle

Once the transaction settles, facilitator lets the backend know and backend responds to user 

x402 meant for more than base and USDC so ofac check is future proof 

If you’re an AI dev you don’t want to touch anything related to checking onchain data that you don’t have to

but what's the flow?

also, doesn't USDC already not allow sanctioned addresses to move funds? I thought the base sequencer just forbid transactions touching sanctioned addresses?

It verifies the payment isn’t coming from a sanctioned address then settles it onchain and pays the tx fee

The idea is to mitigate an API seller’s need to know or integrate anything related to crypto