Live on Robinhood Chain · 4663
Gas for fresh wallets. No funding link.
Buy gas stamps from any wallet. Spend one from a brand-new address holding 0 ETH. The relay signed the stamps blind: it cannot tell which purchase paid for which operation.
- $ stamp buy --count 1
- PostOffice.buy · 1 serial, blinded in the browser
- signed blind by the relay0x67d7…9cb6 ↗
- $ stamp send --from fresh
- from 0x0119…017D · 0 ETH · transfer 0 USDG
- included · gas paid by the paymaster0x3851…83f1 ↗
- $
01How it works
Buy, keep, send.
The app has three screens, one per step. Nothing links the wallet that pays to the address that sends.
- 01
Buy stamps from any wallet.
Pick how many. Your browser draws a random serial for each and blinds it before anything leaves the page. You pay the PostOffice in ETH from your usual wallet; the relay signs the blinded serials without ever seeing them.
- 02
Keep them in your browser.
The browser unblinds the signatures into stamps that verify under the issuer's published key. Export them encrypted, import them on another device or in the agent. A stamp is a bearer token: guard it like cash.
- 03
Spend one stamp per operation.
A brand-new address holding 0 ETH sends its transfer with a stamp attached. The relay checks the signature and that the stamp was never used, co-signs, and the paymaster pays the gas and records the stamp as used on chain.
- 00
No ETH at all? Mine a free stamp.
Your tab solves a small keccak puzzle bound to the operation, and the paymaster accepts that work instead of a bought stamp. Free stamps share a budget every 15 minutes: when it is spent, wait for the next window or use a bought one.
02Privacy
What stays hidden, and what does not.
A stamp removes one link: the funding transaction. Everything else on chain stays as public as it always was.
Hidden
The funding link
No ETH ever reaches the fresh address, so no top-up transaction ties it to your wallet.
Which purchase paid
The relay signed blinded serials. When a stamp comes back, it cannot tell which purchase, or which buyer, it came from.
Your key
Generated in your browser and kept there, encrypted when you ask. The relay never sees it.
Still visible
Your purchase
Buying stamps is a public transaction from your wallet: the PostOffice records who bought how many.
What you send
Assets a fresh address receives link the sender to it, publicly and permanently. Every operation is public on chain.
Your IP and your timing
The relay sees the IP address at purchase and at use. Buying then using at once makes the two easy to pair.
To keep it that way
- Wait a while between buying and using.
- Buy several stamps at once and use them over time.
- Reach the relay over Tor or a VPN.
03Uses
An address nobody funded.
A fresh wallet
Move stock tokens out without a top-up.
Since September 29, 2026, a plain transfer on Robinhood Chain costs ETH again. Send your stock tokens to a fresh address and move them on with a stamp: no top-up from your main wallet.
A receive address
One address per payer.
Hand out a new address for every invoice or counterparty. Whatever it receives, it can forward later with a stamp, without ever being funded.
An AI agent
Agents buy stamps too.
The MCP server lets an agent buy stamps from a payer account, keep them encrypted, and send from fresh accounts with postage "stamp". It refuses to use stamps for a payer's own operations.
04On mainnet
Four contracts. Read them yourself.
Live on Robinhood Chain since 25 October 2026. The first stamped operation, the first mined one and every figure on the stats page come from these addresses.
| Contract | Role | Address |
|---|---|---|
| StampPaymaster | pays the gas | 0x0AE674eA03A1F174EB09E2ac5fc913bC6b4130eF |
| PostOffice | sells the stamps | 0x9d72BA27e3F8f3ddb74dfc6328968289Be2F4F02 |
| DeadLetterOffice | buys $STAMP, sends it to 0x…dEaD | 0xF4Dc84ee0B40AeC7AdA0EFCee8Ab464e352E8116 |
| CreatorFeeSink | creator fees → treasury | 0x1eF52798D579e318E7eD10E794a23389C08D6791 |
- 01PostOfficeA stamp costs the relay's gas quote plus a 25% markup. The gas share goes into the paymaster's deposit.
- 02DeadLetterOfficeThe markup buys $STAMP on its Pons v2 market and sends it to 0x…dEaD.
- 03CreatorFeeSink$STAMP creator fees go into the paymaster's treasury, which pays for the free stamps.
05Developers and agents
Ten lines of SDK. Or one MCP server.
The SDK blinds, pays, unblinds and sends; the agent does the same over MCP, with its stamps encrypted on disk.
import { buyStamps, createRelayClient, sendStampedUserOperation, transferCall } from "@paravion/sdk";
const relay = createRelayClient("https://relay-production-fb81.up.railway.app");
// 1. From any wallet: buy stamps (the serials are blinded right here)
const { stamps } = await buyStamps({
relay,
count: 10,
pay: (call) => wallet.sendTransaction(call),
savePending: (booklet) => store.put(booklet),
});
// 2. From a fresh key holding 0 ETH: one stamp, one operation
await sendStampedUserOperation({
relay,
owner: freshKey,
call: transferCall(token, to, amount),
stamp: stamps[0],
});$ claude mcp add --transport stdio --scope user \
--env PARAVION_NETWORK=mainnet \
--env PARAVION_PASSPHRASE="$PARAVION_PASSPHRASE" \
--env PARAVION_MAX_AMOUNT='USDG=50,ETH=0.01' \
paravion -- node /path/to/paravion/packages/agent/bin/paravion.mjs mcp06Questions
Before you buy.
Is this a mixer?
No. A stamp pays gas for one operation and nothing else; it is never refunded and never carries value. Assets move exactly as they would with ETH for gas, in public.
What does the relay learn?
At purchase: your wallet, how many stamps, the blinded serials and your IP address. At use: the fresh address, the operation, the stamp and your IP address. The blinding keeps it from pairing the two, as long as your timing and IP do not.
What if I lose my stamps?
Stamps live in your browser. Export them (encrypted with a passphrase) and keep the file; lost stamps cannot be reissued, because nobody, the relay included, knows which serials were yours.
Can a stamp be used twice?
The relay refuses a stamp it has seen, and the paymaster records every stamp's nullifier on chain. A double spend that got through anyway would be public, with its first use, for anyone to see.
How long do stamps last?
Stamps are issued in 30-day windows and stay valid 120 days after their window closes. The issuer's keys and windows are published, so the relay cannot hand out stamps that single you out.
Where does the money go?
The gas share of a stamp pays for gas. The markup buys $STAMP and sends it to 0x…dEaD. The $STAMP creator fees pay for the free stamps.