Start chatting

Katara’s chat app runs in the browser. Sign-in is an email and password; the wallet that pays for replies is created from that login and secured by a passkey on your device.

1. Sign up

Open the chat app, choose Create account, and confirm your email.

2. Create your wallet

Open Account → Wallet in settings and choose Create wallet. Your browser asks for a passkey (Touch ID, Windows Hello, a security key). That passkey is the only thing that can sign for the wallet. Katara never has its keys.

You will see an address. That is where USDC lives.

3. Add funds

On the public test network, click Claim under Test USDC for 5 test USDC a day. On the production network, send USDC on Base to your address, or buy it with a card when that option is enabled.

4. Approve spending

Chat is paused until you approve spending. The Approve spending button asks for one passkey signature and lets Katara pull the exact cost of each reply from your balance, up to your budget, for the period you pick (30 days, 6 months, or a year). Nothing is deposited. You can withdraw the approval at any time.

By default the budget follows your balance. Set a cap in the same panel if you want a hard limit.

5. Chat

Pick a model in the header and send a message. Under each reply you see its cost. The balance in the header updates after every reply.

If the provider that was serving your model goes away mid-conversation, the next reply comes from the managed fallback and is labelled as such. See Fallback.