An HTTP API for zero-knowledge proofs: prove that balance, stake,
account age or tx count meets a threshold — the verifier learns only
that, never the value. Five Groth16 circuits, zero public signals in
the proof. Settles on Base mainnet in real USDC, 1 USDC per call over
x402, no account. Limitation, stated on the landing page: the
ceremony is single-party, so proofs are forgeable until three
independent parties take part.
