Answering the three x402 problems
Double-spend, metered billing and the refund round-trip, answered with a collateral-backed x402 scheme.
4Mica gives agents one place to pay on credit, earn yield, and settle on any chain, in any asset, without per-transaction fees or locked capital.
Architecture
Collateral earns at the bottom, credit clears in the middle, and only net positions reach the chain.
01 · Deposit
Collateral is deposited once and keeps earning yield underneath.
02 · Spend
Each request pays over x402 with a signed guarantee. Nothing touches the chain.
03 · Netting
4Mica nets the cycle: 55 guarantees become one position per participant.
04 · Settle
One net payment settles on-chain. Collateral covers any default.
Same x402 protocol. Same HTTP clients. Works with any x402 facilitator.
Blog
Engineering notes on x402, credit-backed clearing, and the infrastructure behind agentic payments.
Cloudflare Radar shows AI agents refused twice as often as training crawlers — and priced ten times as often. The demand is measured; the mechanism is still missing.
The payment rails for agents are built. The clearing layer is the race now — and the question is whether it asks who an agent is, or whether it is good for the money.
Card networks, ACH and per-request on-chain settlement all fail at agent scale. The fix is decades old — separate authorization from settlement and clear.
FAQ
Withdrawals are request-and-finalize with a delay in between. Finalization requires the configured grace period to pass and no obligations preventing it, so check open guarantees before withdrawing collateral. Durations are deployment parameters, not fixed constants.