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Quickstart

From nothing to a private payment on the testnet, with test money, in a few minutes.

Before you start

You need a Solana wallet in your browser: Phantom, Solflare or Backpack. On a phone, open the app inside your wallet's own browser; the app offers a link into Phantom's and Solflare's apps when your phone's browser has no wallet.

Set the wallet to devnet, the Solana network the testnet runs on:

  • Phantom: open its settings, then Developer Settings, turn on Testnet Mode and choose Solana Devnet.
  • Solflare and Backpack: in the settings, choose Devnet as the network.

On devnet your wallet shows test money only, which is worth nothing. Your real tokens on Solana are never touched.

1. Connect your wallet

Open app.opacus.tech and choose Connect a wallet, then your wallet in the list.

2. Open your Opacus account

Choose Sign to open. Your wallet shows a message that names opacus.tech and asks for a signature. Signing it sends nothing and costs nothing: the signature becomes your account's key.

The first time on a device, your wallet signs twice. The second signature shows that your wallet signs the same way every time, which is what lets it open the same account again, on any device. After that, one signature a visit.

3. Get test money

A new account shows Start here. Choose Get test funds: the testnet gives your wallet 1,000 test dollars (tUSD), and a little devnet SOL for the network's fees if your wallet has almost none. Once a day per wallet.

4. Deposit

Choose Deposit tUSD (or Deposit under your balance), type an amount, and approve it in your wallet. A few seconds later it is in your private balance.

A deposit is public on Solana: your wallet and the amount can be read by anyone. What you do with the money afterwards is not. A round amount, like 100 or 250, is harder to match to what you do next than an odd one.

5. Pay privately

Choose Send. Then either:

  • To an Opacus address: paste the address (it starts with opacus1), or type a short name like @ada. Add a note if you like, then Send privately.
  • As a link: choose As a link and Create the link. Anyone who opens the link can claim the money, into their own Opacus balance or out to any wallet.

A payment inside the pool is free and takes a few seconds. Nobody but you and the person you paid sees the amount, the asset, the note or who paid.

To see a payment arrive, open the app in another browser with another wallet, or send yourself a link and open it.

6. Cash out

Choose Cash out, type an amount and the Solana wallet it goes to, and confirm. The wallet receives it less a small fee. A cash-out is public like a deposit: the wallet and the amount, not whose balance it came from.

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