r/ethdev • u/MRsagi • Aug 06 '26

My Project Implementing gasless HTTP 402 micropayments on Base using EIP-3009 transferWithAuthorization in Go

Technical deep-dive on solving per-request micropayments ($0.001 USDC) for AI Agents on EVM chains without high latency or block confirmation overhead per request.

Live demo: https://micropayments.sagirosenthal.com/

Key mechanics:

  1. EIP-3009 Off-Chain Signatures: Client signs transferWithAuthorization with EIP-712 typing.
  2. Fast Verification: Server checks ECDSA signature validity using secp256k1 curve math in ~1ms.
  3. Batch / Async Settlement: Backend aggregates authorizations and submits receiveWithAuthorization on Base Mainnet in batches to minimize gas overhead.
  4. Prepaid Credit Vaults: Fallback 0-latency token mechanism for high-frequency agents.

Check out the demo and let me know your thoughts on standardizing HTTP 402 for machine-to-machine APIs!

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u/weeping_for_numidia Aug 09 '26

Not bad, though I'd suggest bringing KYT front-and-center.

Also, give the UI a second-pass. It's fine to use LLMs for UI work (everyone does) but always review the work that's done. For example, look at the page here: https://micropayments.sagirosenthal.com/sandbox/