From install to your first payment

1. Open the Download page and get Fiber Studio for your computer.
2. Install the app, then open it.
3. On first launch, the Setup wizard starts automatically. Click Continue on the welcome screen.

The wizard configures a local official Fiber Network Node (fnn). Your key stays on this computer — Fiber Studio is not a hosted wallet.

1. On Choose a network, select Testnet, then Continue. Mainnet is not available yet.
2. On Connect to public network, click Use public node1 or Use public node2 (or paste a peer pubkey), then Continue.
3. On Wallet key, paste your CKB private key (64 hex characters; 0x prefix is OK), then Continue.
4. On Wallet password, enter and confirm a password, then Continue. Fiber Studio stores it in your OS keychain when you finish.
5. On Review & start, check Network, Peer, and Wallet key, then click Start node.
6. Wait until the top bar shows fnn running and a Testnet badge. You are now in the main app.

If start fails, read the error on the review screen. Common causes are a bad key format or a password that does not match.

Fiber payments need an open channel with capacity. First make sure your saved peer is connected, then fund a channel.

1. In the sidebar, open Network.
2. Find your saved peer. If it says Not connected, click Connect and wait for Connected.
3. In the sidebar, open Channels, then click Open channel.
4. Choose the connected peer, pick an Asset (CKB or a whitelisted UDT such as RUSD), set capacity, then confirm Open channel. For CKB, capacity must be at least 1,000.
5. Wait until the channel State shows Ready (opening can take a short while). Do not send payments until it is Ready.

Opening a CKB channel spends on-chain testnet CKB from your funding wallet. UDT channels need that token on-chain and in your node whitelist. Check Assets for balances. Channel local balance is separate from on-chain once the channel is Active.

With a Ready channel, you can move CKB or UDTs over Fiber from Payments — or pay a Bitcoin Lightning invoice with cWBTC through a Cross-Chain Hub.

1. In the sidebar, open Payments. Send is on the left; Receive on the right.
2. Under Send, choose Fiber (invoice), Keysend, or Lightning (BOLT11 via CCH).
3. Fiber invoice: paste a string starting with fibt. Keysend: pick a recipient, asset, and amount. Lightning: set a hub URL in Settings → Cross-chain first, then paste lntb… / lnbc… (pasting a Lightning invoice into Fiber auto-switches tabs).
4. Check the preview or hub quote, then click Review payment or Review Lightning swap.
5. Confirm in the dialog and wait for success.

Lightning swaps need cWBTC channel liquidity toward the hub. Testnet cWBTC is available from the cWBTC faucet.

1. Stay on Payments.
2. Under Receive, click Create invoice for Fiber (CKB or a UDT), or Receive BTC if a CCH hub is configured.
3. For Fiber: choose the Asset, amount, optional note, and expiry, then create the invoice and share the string.
4. For BTC: enter a cWBTC amount; the hub returns a Lightning invoice for the payer. Status updates as the swap settles.

You can also start send or create-invoice flows from Home, and check CKB/UDT balances on Assets.