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Smart wallet

How your Umia wallet works: signing in, sending and receiving funds, staying secure. No prior crypto experience required.

Umia gives you a wallet the moment you sign in. No app to install. No seed phrase to write down. No prior crypto experience required.

This page has three parts, depending on where you're coming from:

  1. The basics: what everyone needs to know to start using Umia.
  2. If you've used crypto before: how Umia's wallet differs from what you're used to.
  3. For developers: the implementation details.

The basics

Signing in

You sign in with Google, Twitter, or GitHub, just like any other app. There's nothing to install, nothing to write down, no recovery phrase to memorize.

The account you signed in with is what gets you back to your wallet later. If you sign out and come back tomorrow with the same account, you'll find everything exactly where you left it.

Your wallet address

Umia creates a unique address for you. Think of it like an account number for receiving money. It shows up at the top of the app and in the Deposit screen. Share it with anyone who wants to send you funds.

The same login always gives you the same address. It doesn't change.

How you pay for things

Most apps in this space make you hold a separate currency just to pay small fees for every action. Umia doesn't. Whether it's placing a bid, entering a market, or claiming a reward, the fee is handled for you. Most of the time, using Umia feels free.

You don't need to top up anything special ahead of time. Show up with the amount you want to spend, and you can use it.

Adding funds

Open Deposit from your account menu. You have two ways to put money in:

  • Buy: use a card, Apple Pay, or bank transfer to buy funds directly into your wallet.
  • Receive: copy your address and send funds from another wallet or exchange.

Funds show up in your balance within seconds of arriving.

One click, one confirmation

Some actions need several steps behind the scenes. Umia handles that for you. You'll see one confirmation, sign once, and either the whole thing happens or none of it does. There's never a half-finished state where some steps ran and others didn't.

Getting your money back out

You're not locked in. You can withdraw or move your funds at any time. From your account menu, you can also export the key that controls your wallet. If you ever decide to leave, you take your wallet with you.

If you lose access to your login

Recovery runs through whatever login method you used. Lost your Google account? Go through Google's recovery. Same for Twitter or GitHub. Once you're back in, your wallet is back.

Your wallet's safety is tied to the account you signed in with. Keep 2FA on, don't reuse passwords, and treat that account the same way you'd treat any account that holds money.

Common questions

Where is my money actually stored? In your wallet, an account tied to your login. Umia doesn't hold it; you do.

What if I lose my phone or computer? As long as you can sign back in with the same login from any other device, you're fine. Nothing important is stored on the device itself.

What if a transaction fails? Your funds stay exactly where they were. The app tells you what went wrong in plain language.

Is it safe? Your wallet is as safe as the account you signed in with. Keep that account secure (strong password, 2FA) and you're in good shape.

If you've used crypto before

Your Umia wallet is a smart wallet. Specifically, an ERC-4337 account (the Kernel implementation) controlled by a Privy-managed embedded signer. Two practical differences from a typical EOA:

  • You don't hold gas tokens. A paymaster sponsors gas on every transaction; you never need the network's native token to do anything.
  • Transactions are batched atomically. One UserOperation replaces the approve-then-exec chains that normally need multiple confirmations. Either the whole batch lands or the whole batch reverts.

The address shown everywhere in the app is the smart-account address, not the signer. The signer is an EOA that Privy manages for you; it lives at a different address and you don't normally interact with it directly. Send funds to the smart-account address (the one shown in Deposit), not to the signer.

Can I bring my own wallet? Yes. Connect MetaMask, Rainbow, or any injected wallet from the login screen. You lose the smart-wallet features (batching and sponsored gas) and pay gas in the network's native token as usual, but everything else works the same way.

Can I export? Yes, from the account menu. Export gives you the signer's private key. That signer controls the Kernel smart account, so importing it into tooling that understands Kernel lets you keep using the same smart-account address from elsewhere.

Why doesn't my balance match what I see on a block explorer? You're almost certainly looking at the wrong address or the wrong chain. Make sure you're using the smart-account address (the one in Deposit), on the network Umia is running on, not the signer EOA.

Do transactions show up as normal eth_sendTransaction calls on-chain? No. They're UserOperations submitted via a bundler and routed through the account's EntryPoint. Explorers with AA support (including ERC-4337 indexers on Etherscan and similar) will decode them; older views just show the bundler's wrapper transaction.

For developers

Implementation lives in web/hub/:

  • components/providers.tsx: Privy + SmartWalletsProvider + paymaster context wiring
  • hooks/use-active-wallet.ts: routes the "active" address to smart-account vs signer EOA; source of truth for every address-keyed read in the app
  • hooks/use-smart-write.ts: writeContract for single calls, sendCalls([...]) for atomic batched UserOps on the smart wallet (throws if you try to batch on the EOA fallback path)
  • lib/paymaster.ts: Pimlico sponsorship policy wiring consumed by SmartWalletsProvider

External references: