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Fillers

Fillers make fast swaps possible. Instead of making the user wait the full two Bitcoin confirmations (~20 minutes) a standard swap needs, a Filler watches the Bitcoin mempool, sees a valid request, prepares the swap (executing BTC → the requested token so the rate is locked in at that moment), and delivers the tokens to the user after a single confirmation — about ~10 minutes, at the best rate available when it acted.

How a filler is repaid​

The Filler fronts the user their tokens after one confirmation. Once the user's Bitcoin transaction reaches the standard two confirmations, the freshly minted TeleBTC is routed to the Filler instead of the user — repaying the Filler for what it advanced.

Incentives & risk​

  • Fee — Fillers earn a fee for the speed they provide. The fee is optional: users who don't mind waiting can skip it and settle normally.
  • Risk — by paying after one confirmation instead of two, the Filler takes on the extra re-org risk that the protocol otherwise makes users wait out. That's the service they're paid for.

Why it matters​

Standard swaps are exposed to ~20 minutes of price movement, which can cause a swap to miss its minimum-output and fail. By preparing the swap the moment the request appears and delivering after one confirmation at close to the current market rate, fast swaps reduce failure rates as well as latency.

See Fast Swaps for the full flow.