Payments

All payments are MUSD on Mezo. Each one is a transaction you sign in your own wallet, and Keel shows it as sent only after it is confirmed on-chain, three blocks deep.

#Send to @username

send 20 to @ada for lunch in chat, or Pay → Send in the app. The recipient can be:

• a Keel user's @username, which Keel resolves to the wallet linked to that account;
• any 0x address.

If the @username has no wallet on Keel yet, Keel offers a claim link instead. Once the transfer confirms, the recipient gets a Telegram notice. If they've never started the bot, the notice waits for them.

#Split bills

Pay → Split or /split 90 @ada @bob dinner.

• Shares can be equal, custom amounts, or percentages, computed in whole cents.
• In a group, Keel posts a live card: each person taps Pay, signs, and the card ticks them off once the payment is matched on-chain (sender, recipient and amount).
• The creator can send reminders, and Keel can remind people automatically before a due date.
• If someone can't be reached on Telegram, Keel gives the creator a link to forward.

#Requests

/request 25 for tickets in a group posts a request anyone can pay. The message updates as payments confirm.

#Claim links

A claim link sends MUSD to someone who has no wallet yet.

sequenceDiagram
  participant S as Sender
  participant P as KeelPay (escrow)
  participant R as Recipient
  participant K as Keel relayer
  S->>S: Mini App creates a one-time key (in the browser)
  S->>P: create(link address, amount, expiry): MUSD escrowed
  S-->>R: shares t.me/KeelMezoBot/app?startapp=claim_<key>
  R->>R: opens the link, creates or connects a wallet
  R->>R: signs Claim(link, to) with the link key
  R->>K: signature + destination
  K->>P: claim(link, to, signature): pays the gas
  P->>R: MUSD arrives

Security of the link key:

• The key is created in the sender's browser and exists only inside the link. It is 43 characters of base64url, which fits Telegram's startapp limit. It goes straight to the Mini App and never reaches Keel's bot.
• Claiming needs a signature over Claim(link, to), which binds the destination address. The relayer, or anyone watching the mempool, can't redirect the funds.
• Anyone who has the link can claim it. Send it only to the person it's for.

Expiry and refund:

• Links expire after 72 hours by default.
• An expired or cancelled link refunds the full amount to the sender. The sender can cancel at any time from Activity.

Gas: Keel's relayer pays the claim transaction's gas, so the recipient needs no BTC. If the relayer is low on gas, claims pause and Keel's admins are alerted; the link keeps working.

Upgrades: links made on the first KeelPay contract stay claimable and cancellable. Keel looks up which KeelPay holds each link.