Coins and networks

What AirWallet does for each coin: Bitcoin address types, Ethereum and its seven other networks, Solana, Monero and Zcash.

AirWallet holds five coins: Bitcoin, Ethereum (with seven more networks that use Ethereum addresses), Solana, Monero and Zcash. One recovery phrase covers all of them. This page covers what's particular to each.

For receiving and sending in general, see Receive and Send. For tokens, swaps and staking, see Tokens, swaps and staking.

#Bitcoin

#Address types

A recovery-phrase wallet has Taproot and SegWit addresses, and gives a fresh one for each payment (see Receive). A single Bitcoin key has one address of each kind it supports.

Settings → Bitcoin address chooses Taproot (bc1p) or SegWit (bc1q): where Receive points and where change goes. Coins on either kind are spent together.

#How AirWallet handles your coins

A Bitcoin balance is made of separate coins, one for each payment you received and each bit of change. AirWallet picks which coins pay for each send. Change goes back to your wallet: to a fresh change address for a recovery-phrase wallet, or to its own address for a single key.

• Speed on Send sets the fee: Fast · ~10 min, Normal · ~30 min or Slow · ~1 h.
• A payment that hasn't reached a block yet can be sped up with a higher fee (see Send).
• One transfer can pay up to 20 addresses.
• The offline device checks that every coin it signs for is its own, shows every output (recipients and change) and the fee, and refuses outputs it can't show.
• A data note (OP_RETURN) is allowed if it holds no bitcoin. Bitcoin put in one would be burnt, so the signer refuses it.
• A transaction that can't be sent before a certain block shows that block. One locked until a date is refused.

After you import a recovery phrase, the online copy looks for the phrase's other accounts and addresses that have been used (Bitcoin's other addresses and accounts, Ethereum's and Solana's other accounts), and offers to add each one as a wallet of its own.

The online copy reads balances from public Bitcoin servers (mempool.space by default, with others as fallbacks). To use your own, go to Settings → Bitcoin and Ethereum servers.

#Ethereum and its networks

Your Ethereum address is the same on all eight networks:

To send on a network, pick the coin or token on that network in Send's Asset list. You need that network's own coin to pay its fee.

#Fees

AirWallet asks the network itself what a payment needs: the gas limit is the network's own estimate for that exact transaction, and the fee follows recent blocks. The Confirm screen shows "about" what the payment will likely cost and "at most" its ceiling.

Base and Optimism also charge an L1 data fee on top of gas. AirWallet includes it in the fee it shows, and takes it off the amount of a Max send. The offline device's review names it too: "plus a small L1 data fee, charged by the network".

Each network has a fee limit above which AirWallet asks once more before sending or signing (see Send).

#Tokens

Each network has a built-in list of well-known tokens, such as USDC and USDT, and you can add any other token by its contract. See Tokens, swaps and staking.

#What the offline device signs on Ethereum

From its own codes, the offline device signs:

• payments of the network's coin
• token transfers (ERC-20 transfer)
• removing a token approval (see Notifications and approvals)

It refuses everything else, because it can't show you completely what it does: giving an approval, other contract calls and creating a contract. The exception is a Safe multisig's transactions, which come through MetaMask or Rabby and are shown line by line (see Multisig).

The online copy uses public servers for each network. Settings → Bitcoin and Ethereum servers has a field for each network if you want your own.

Activity and the token approvals check come from free block explorers. BNB Chain has no free one, and the free ones can be busy. If you have an Etherscan or Blockscout API key, paste it into Explorer API key in the same place. AirWallet then asks your explorer only for the networks the free ones could not answer. A free Etherscan key covers most networks; BNB Chain needs Etherscan's paid plan. The explorer that owns the key sees which addresses it is asked about.

#Solana

A Solana wallet holds SOL and Solana tokens. On Solana, AirWallet can also:

• swap tokens through Jupiter
• stake SOL with a validator
• close empty token accounts and get their SOL back

All three are described in Tokens, swaps and staking. Swaps and staking work from watched wallets too: the offline device checks and signs them.

#Signing Solana offline

A signed Solana transaction normally expires after about a minute. For a watched wallet, the code on the online copy renews itself every 15 seconds until you scan it, and the signed answer has to be sent within about a minute.

If a signed Solana payment expires, nothing is sent: make the code again and sign it.

To remove the time limit, turn on Settings → Durable nonce for offline signing on the online copy. The next send from each wallet first asks to set up its nonce account. That is a one-time transaction, signed on the offline device like any other, that holds about 0.0015 SOL. The SOL stays yours and comes back when you close the account. After that, a signed code stays valid until it's sent.

The offline device signs only a durable nonce that belongs to your wallet. A pending send signed with one can be called off from the offline device (Call it off).

You can also type a Solana transfer on the offline device itself: open Send there and select Solana: type a transfer here instead. It needs a recent blockhash from the online copy (there: ⋯ (More) → Offline signing… → Show blockhash).

The online copy uses Solana's public servers. A paid server of your own (Settings → RPC URL) makes Solana faster.

#Monero

Monero payments are private: amounts and addresses don't show on the blockchain. That changes how watching and offline signing work. Read the Monero notes in Privacy before you move much.

#Keys and recovery words

• Recovery phrase: a phrase wallet's Monero keys are derived the way Cake Wallet derives them, so Cake restores the same Monero wallet from the same words.
• Polyseed: + → Create → Monero wallet (Polyseed) makes a Monero-only wallet with 16 words, the seed Feather, Cake Wallet and ANON use. It knows the month it was made, so restoring it scans from there. You can import 16 Polyseed words too. Encrypted Polyseeds aren't supported.
• Monero's 25 words: you can import them, and Export private key shows them for any Monero wallet, with its restore height ("Monero: 25 words for other Monero wallets"). Feather, Cake Wallet, Monerujo and the Monero GUI restore from them.

#Receiving

Receive gives a subaddress (8…) for each payer, and keeps the main 4… address folded away. See Receive.

Coins you receive, and change you get back, can be spent 10 blocks (about 20 minutes) after they arrive. That's Monero's rule.

#Syncing

A Monero wallet finds its coins by downloading blocks and scanning them itself. The node never learns which coins are yours and never sees your keys. It does see your IP address, and the transactions you send.

• AirWallet syncs one wallet at a time: the one on screen first, the others every 5 minutes.
• Settings → Monero node: leave it empty to use the fastest up-to-date public community node (AirWallet switches when one stops answering), or enter your own node. Your own node (monerod) is the private choice.
• Private sync (in the same section): the node isn't told exactly where each wallet left off. Slower: each time a wallet opens, it downloads up to a day of blocks again.
• A wallet you imported starts scanning from today. To find older coins, open ⋯ (More) → Monero: scan from a date… and pick the day of its first XMR, or earlier. Each day further back is about 20 MB more to scan.
• Settings → Proxy (Tor) sends Monero's traffic through Tor too.

The web version at airwallet.tech/online uses Cake Wallet's public node for Monero.

#The view key

To watch a Monero wallet, the online copy needs its view key, which travels in the offline device's Show to my online wallet code. A Monero address alone shows nothing, because what arrives is private.

With the view key, the online copy sees what arrives and how much. It can't spend, and it can't tell on its own what's been spent: only the spend key, which stays on the offline device, can work that out. If the view key leaks, you lose privacy over incoming payments, never coins.

#Sending from a watched wallet: one extra step, once

The first send from a watched Monero wallet takes two rounds:

1. Step 1 of 2: which coins are spent. The online copy shows a code. The offline device scans it (nothing to approve) and answers with a code that says which coins are already spent. Scan that answer on the online copy.
2. Step 2 of 2. The online copy goes straight on to the transfer itself. The offline device shows what it pays, including the change, and signs.

After that, every send is one round: each signed transfer carries the spent-coin information back. If the same keys spend coins somewhere else, the node refuses the next send as a double spend, and AirWallet asks for step 1 again.

#Coin control

⋯ (More) → Monero: coins… lists the coins your balance is made of, largest first, each "ready" or "ready in about N min".

• Freeze a coin so it's never spent until you Unfreeze it.
• Add a label (the pencil): a note for you, kept on this device only.
• Tick coins, then Send from N coins to pay with those only.
• Split into coins… turns what's ready into 2, 4, 6 or 10 coins of one size in your own addresses, for one fee. After the usual 10 blocks, each can be sent on its own, so payments one after another don't wait for change.

For a watched wallet, freezing and picking coins work after the first step of a send.

Settings → Monero node → Ready for back-to-back sends does something similar automatically: each send also keeps a few coins of the same size in your own addresses, for a little more fee.

#Paying several people and proving payments

• Pay several people pays up to 16 addresses in one transfer.
• In a Monero payment's details, Prove it… makes a proof for one person: a Payment proof, the Transaction key or a Spend proof for a payment you sent, and a Receipt proof for one you received. Each says on screen what it reveals.
• ⋯ (More) → Monero: prove a balance… shows that the wallet holds at least an amount. It names the coins it counts, so whoever checks it can later see when you spend them.
• ⋯ (More) → Monero: check a proof… checks someone else's.

A payment sent from a watched wallet can't be proven from the online copy yet: its transaction key exists only on the offline device.

#Monero's next upgrade

Monero's next upgrade (FCMP++) will change how transactions are signed; it has no mainnet date yet. If the network moves to an upgrade AirWallet doesn't know, the online copy stops sending and says to update AirWallet on both devices (the offline one too). Your addresses stay the same.

#Zcash

Zcash has shielded (private) and transparent (public) coins. A Zcash wallet in AirWallet has both kinds of address. Read the Zcash notes in Privacy.

#Pools

Ironwood was added to Zcash in July 2026 (network upgrade NU6.3), after a flaw was found in Orchard. It uses Orchard's design and the same addresses: payments to the Orchard part of your address now land in Ironwood.

#Addresses

• The shielded address (u1…) holds an Orchard and a Sapling receiver. Receive gives each payer a new one, and nobody can link them.
• The transparent address (t1…) is public. Use it only for exchanges that can't pay a shielded address.

#Shielding transparent ZEC

AirWallet spends only shielded coins. To use transparent ZEC you received, open ⋯ (More) → Zcash: shield transparent ZEC…. It moves the transparent coins into your shielded balance in one transaction. This keeps your shielded and public coins from being linked.

#Sending

• Send pays u1…, zs1…, t1…, t3… and tex1… addresses. A tex1… address takes two transactions (a transparent hop first).
• A payment to a shielded address can carry a private Memo (up to 512 bytes). Transparent addresses can't receive memos.
• Pay several people pays up to 20 addresses in one transfer.
• The usual fee is 0.0001 ZEC. Above 0.01 ZEC AirWallet asks once more.
• The review shows each payment, the pool it arrives in, any memo, which coins it spends and the change.
• Sending first makes a proof that the transaction is valid. That takes a few seconds, longer when Sapling coins are involved. The first time a send spends or pays Sapling, AirWallet downloads Zcash's Sapling parameters once, checks them and keeps them.

#Viewing keys and watching

A Zcash wallet's viewing key (uview1…) sees everything the wallet receives and sends, amounts and memos included, and can't spend any of it. If it leaks, you lose that privacy, never coins.

• ⋯ (More) → Zcash: viewing key… shows it, for an accountant, an auditor or another wallet that should watch.
• The offline device's Show to my online wallet code carries it, so your online copy can watch the wallet and prepare sends.
• A viewing key pasted on its own (exported from another wallet) is watched only.

A send from a watched Zcash wallet is one round. The online copy makes a partly built transaction (a PCZT) and starts the proofs; the offline device checks every output, amount and the fee against its own keys, shows them and signs; the online copy combines and sends it.

#Syncing and the server

The online copy downloads compact blocks and finds your coins itself. The server never sees your keys or which shielded payments are yours. It does see your IP address, the transparent addresses it's asked about and the transactions you send.

• The default server is zec.rocks. Settings → Zcash server takes your own.
• A wallet made in AirWallet starts scanning from the day it was made. An imported phrase starts a day back. For older coins, open ⋯ (More) → Zcash: scan from a date….

The web version at airwallet.tech/online uses zec.rocks too.

#Recovery phrases and other Zcash wallets

Your recovery phrase's Zcash account is the one Zodl (formerly Zashi), Zingo, Ywallet and Keystone derive. Zodl restores only 24-word phrases. New recovery phrases in AirWallet have 24 words; a 12-word phrase works in AirWallet, Keystone and Zingo, but not in Zodl. When another wallet asks for a birthday, give the date the wallet was made, or earlier.

#Network upgrade NU7

Zcash's next upgrade, NU7, brings 25-second blocks. It's live on testnet; its mainnet height is set on October 20, 2026, and it's expected to activate around November 5, 2026. A transaction signed for the old rules is refused after it activates.

AirWallet is built for it: the online copy learns NU7's height from the Zcash server and makes NU7 transactions from its first block, and the offline device accepts NU7 transactions without needing to know the height. If an update comes out before November 5, install it on both devices.