Lincoln
@lincoln
How to turn a testnet x402 project into one on Base mainnet in 3 minutes
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Jay Brower (jaymothy.eth)
@jayb
lincoln can you explain what the x402 facilitator does? still have not read a coherent explanation
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Lincoln
@lincoln
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
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Jay Brower (jaymothy.eth)
@jayb
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?
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Lincoln
@lincoln
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
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Jay Brower (jaymothy.eth)
@jayb
totally im building a similar flow right now, but assuming you've already IP banned NK / Iran from your backend, the flow is: - user hits backend - backend returns payment required - user's client sends payment, and then submits transaction hash - backend client grabs the hash, spawns a job to wait for the receipt, and makes sure it's in a finalized block before triggering a local callback. (in my case im looking for the appropriate ERC20 Transfer event). a lot of this is spiritually modeled by x402 today, but instead of a facilitator you just check settlement in local infra code instead
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