Pay with USDC or USDT. No gas. No noise.

Send and receive stablecoins. The fee is paid in the asset you hold.

Available now Chrome Web Store Live
Download on the App Store Coming soon
GET IT ON Google Play Coming soon

Browser extension available now for Chrome, Brave, Edge and Opera. Coming to iPhone and Android — iOS is the reference build.

See how the browser extension works →

Just pay with USDC or USDT. That's it.

A dead-simple wallet for sending and receiving stablecoin dollars. No gas tokens. No hunting for your money.

Just pay with USDC or USDT. That's it.

Send and receive USDC and USDT simply. Your money is stablecoin dollars. Clear balances, always visible.

No gas tokens, ever.

You pay the network fee in the same asset you hold — USDC when you send USDC, USDT when you send USDT. Never buy or hold ETH, SOL or other gas coins just to move your money. This is the killer feature.

You always find your money.

One clear balance. One Send. One Receive. Unlike wallets that bury your balance under charts and tabs, here it's right in front of you.

It's yours.

Self-custody. Keys live on your device. Face ID and PIN protect access. No one else can reach your funds.

Nothing to drain.

Sigma9 doesn't connect to dApps or websites, and it never asks you to sign an unknown smart-contract transaction. It only sends, receives and bridges the assets it supports — so the usual "connect your wallet, approve a shady contract, watch it get emptied" attack simply has no way in.

No trading terminal. No charts. No noise.

A wallet that pays — and stays out of your way.

No price charts or trading tools
No swaps for profit or DeFi yield farms
No NFT gallery or collectibles
No airdrop hunting or meme-coin casino
No feed of tokens you never asked for
No dApp connections — it doesn't plug into websites
No blind-signing of unknown smart-contract transactions
No token approvals a malicious site can use to drain your wallet

If you found other wallets overwhelming, this one is intentionally simple.

How paying works

Three steps. Fee paid in the asset you hold. No extra coins required.

1

Have USDC or USDT

Your balances show clearly in one place.

2

Send

Enter amount and address, or scan QR. Or receive by sharing your code.

3

Done

Confirm with Face ID or PIN. The fee is paid from the same asset you're sending. That's it.

Under the hood

For the technically curious — Circle rails and gasless self-custody

Sigma9 is built for real USDC using Circle infrastructure.

  • Circle CCTP v2 for cross-chain: canonical USDC burn on source, mint on destination. No wrapped tokens.
  • Circle Paymaster fronts gas; you pay the fee in USDC via permit. No native gas token required.
  • Monad and World Chain use a Pimlico ERC-20 paymaster instead of Circle Paymaster (which isn't deployed there), and Solana uses the Kora relayer as fee payer — both still let you pay the fee in USDC.
  • Gasless account abstraction for both same-chain sends and cross-chain transfers.
  • Self-custody: BIP39 seed, keys derived and stored only on your device (iOS Keychain with Face ID + PIN).

Gasless USDC send and gasless USDC cross-chain transfers (CCTP v2) are live and verified on mainnet. Gasless same-chain USDT is live on Arbitrum, Polygon, Ethereum, MegaETH and Solana; the only live USDT0 bridge route is Arbitrum → MegaETH. App store release coming soon.

Gasless USDC on Ethereum, Arbitrum, Base, Optimism, Polygon, Unichain, Monad, World Chain and Solana mainnet (working USDC cross-chain between EVM chains and Solana). Gasless USDT on Arbitrum, Polygon, Ethereum, MegaETH and Solana. One EVM address across EVM chains. Arc mainnet support coming after launch.

Learn more

How gasless USDC works →

Gasless USDC on Monad →

Kora relayer for gasless Solana →

Frequently asked questions →