Light client bridge
The TeleSwap Bitcoin light client is what makes the protocol trustless: it lets the destination chain verify that a Bitcoin transaction actually happened before any TeleBTC is minted or any request is marked complete.
How it works
The bridge is a light-client protocol. Its Relay contract on the destination chain stores Bitcoin's block headers; Relayers continuously submit new headers, which the Relay validates against Bitcoin's consensus rules. Anyone can then submit an SPV (inclusion) proof showing that a specific transaction is included in one of those blocks, and the contract checks it against the stored headers.
Because verification is done by the contract (not by a trusted validator set), the bridge inherits Bitcoin's security and needs no trusted intermediaries — see the Security model.
Where it's used
| Use case | What the bridge verifies |
|---|---|
| Bridge requests (wrap) | A Teleporter submits an inclusion proof; TeleBTC is minted only if the user really sent BTC on Bitcoin |
| Locker payment proof (unwrap) | A Locker proves it sent native BTC to the recipient, completing the request |
| Locker slashing | Anyone can submit proof that a Locker moved BTC without a valid unwrap, triggering slashing |
Why confirmations matter
TeleSwap waits for Bitcoin confirmations before acting on a wrap (see Fees & Speed). This protects against a transaction being re-orged out of the chain, which could otherwise mint unbacked TeleBTC. Fast Swaps let users get tokens before confirmations by shifting that risk to a Filler.