HimitsuAI

Every Himitsu 402 is a fresh encryption under a fresh key, derived from the seller key and that request's nonce. The key a claim writes on-chain opens that order's copy: on any other copy it fails the dHash check. A paywall only claims an order whose keyHash matches its nonce.

Anyone can check a Himitsu delivery proof without an order. verifyDelivery(pub, proof) is a view function on the escrow: the call costs no gas and returns true or false. open() runs the same Groth16 check before it takes the payment and reverts with BadProof when it fails.

A Himitsu seller can turn an order down instead of letting it run to the deadline. decline(id) works on any open order, only from the seller's address, and sends the full amount back to the buyer in the same transaction, no fee. In the app it is the Decline and refund button.

The key to a Himitsu delivery stays in the order. The claim writes it there and getOrder(id).key returns it for good, so whoever kept the encrypted package can open it again any time and check it against the same dHash. payX402 returns that package as deliveryPackage.

The Himitsu SDK 0.2.0 is up. payX402 takes asset: "USDG" with maxPrice in that asset, and calls onStep at each step of a buy. himitsuPaywall takes prices: { ETH, USDG } and answers one 402 with both offers. Clients on 0.1.0 keep working, in ETH. himitsuprivacy.xyz/docs/buil…

Every listing on Himitsu Market now takes USDG as well as ETH. The 402 carries two offers, ETH first, for one sealed delivery: same proof, same hashes. Stock flow is 0.00003 ETH or 0.075 USDG. In the browser: Buy, pick the asset, Lock. In USDG the wallet signs an approve first.

Himitsu MCP installs with one line in Claude Code, or one config block in any other MCP client. Both are on himitsuprivacy.xyz/mcp. On first start it writes a key to ~/.himitsu/agent.key, mode 600, and himitsu_wallet gives the address to fund. No tool returns the key.

Asked for Stock flow, the agent calls himitsu_buy and the chat follows the order from the offer to the decrypted delivery, in about 20 to 30 seconds. Nothing leaves the wallet until the seller's proof verifies. The JSON comes back marked as the seller's data, not instructions.

Himitsu MCP is live. An agent in Claude Code, Claude Desktop, Cursor or any MCP client can buy from Himitsu Market, and it pays only after the delivery proof verifies, under a per-call cap and a daily budget you set. Every listing now takes USDG too. himitsuprivacy.xyz/mcp

Every Himitsu order has a deadline, set by the buyer, up to 365 days out. Before it, the seller can claim with the key or decline, and the buyer can release. After it, claim stops working and anyone can call refund: the buyer gets everything back, no fee.