Agents pay each other in private.

A trading agent that buys pool depth for one token every minute is telling the world what it is about to trade. A research agent that buys the same three feeds reveals its edge. On a transparent chain, plain x402 leaks the buyer, the seller, the amount and the cadence of every call.

Both ends are hidden. The payer side uses a shared pool: deposits from agents are swept into rotating pool addresses and tracked in an internal ledger, and every payment leaves from a pool address, never from the agent's own.

HUSH keeps the x402 shape (HTTP 402, payment requirements, retry with proof) and changes who gets paid. Each call carries a fresh nonce. For each seller leg the gate derives a one-time secp256k1 (EVM) account from its secret and the nonce, and asks to be paid there. Addresses never repeat, so calls cannot be clustered by payee.

Receipts are kept off-chain and published only as commitments. Every hour the new commitments become the leaves of a SHA-256 Merkle tree, and its root is anchored on Robinhood Chain as the calldata of a 0-value transaction sent by the HUSH publisher address to itself. Any receipt holder can prove inclusion with a short Merkle path, checked in the browser at /verify, without revealing any other receipt. Reputation is computed from receipts and published with the epoch roots it came from: verifiable by anyone holding the receipts, opaque to everyone else. This is hashing and on-chain anchoring, not zero-knowledge cryptography.

Funds wait on the one-time address until the seller returns a valid answer. A failed call is refunded from that address. Sellers sweep at their own pace, batching and delaying sweeps to break timing links. Payments are in ETH on Robinhood Chain (chain 4663).

Autonomy needs limits. Each agent wallet has a daily budget, a per-call cap, an allowlist and a kill switch, checked before money moves. Owners keep custody of the top-up and can sweep back at any time.

The sum of everything machines pay machines on HUSH. Shown as one aggregate, never broken down by wallet or seller.

$HUSH launches on Pons, on Robinhood Chain. A share of facilitator fees is set aside for buyback & burn once the token is live. Holders get tiered fee discounts. Contract address: soon.

• Now (live on Robinhood Chain): gate, shop, leash, persistent receipts, Merkle roots anchored on-chain, MCP server, open source.
• Next: seller sweeps with delayed batching, USDC refunds.
• Then: verifiable Hush Score audits over receipt sets, confidential amounts, desktop and mobile apps.

Payer side: agents fund a deposit address that is swept into a shared HUSH pool; every buy is paid from a rotating pool address to a one-time payee, so payer and payee are unlinkable on-chain. Still visible: that a deposit into HUSH happened, amounts and timing (a small pool gives weak cover). The system is custodial: the operator holds the pool keys, the ledger and the derivation secret. No zero-knowledge proofs are involved. Nothing here is financial advice.