Cross-Chain Swaps Explained

The Cross-Chain Problem

Trading between different blockchains has historically been one of crypto's biggest pain points. Want to trade your Bitcoin for Ethereum? You'd typically need to:

1. Deposit BTC on a centralised exchange
2. Sell BTC for a stablecoin
3. Buy ETH with the stablecoin
4. Withdraw ETH to your wallet

Or use a bridge — which means wrapping your tokens (giving you a synthetic version, not the real asset) and trusting the bridge's security. Bridge hacks have resulted in billions of dollars in losses.

How Swaptain Solves This

Swaptain uses THORChain's decentralised liquidity protocol, accessed through SwapKit, to perform native cross-chain swaps. No bridges, no wrapping, no centralised custody of your swap. You trade real BTC for real ETH.

How a Swap Works

Swap Routing

For swaps between two non-RUNE assets (which is most swaps), THORChain performs a double swap:

1. BTC → RUNE (through the BTC/RUNE pool)
2. RUNE → ETH (through the ETH/RUNE pool)

This happens atomically within THORChain, so from your perspective it's a single operation — BTC in, ETH out.

Multi-Leg Swaps

Some routes require multiple steps. For example, swapping a token on BNB Chain for a token on Ethereum might route through an intermediate asset. Swaptain handles this automatically:

1. Sell your source token for a major asset on the source chain
2. Cross-chain swap the major asset to the destination chain
3. Buy the destination token on the destination chain

You'll see the swap progress leg-by-leg in your Telegram notifications.

Streaming Swaps

For larger trades, THORChain supports streaming swaps — your trade is broken into smaller sub-swaps executed over multiple blocks. This reduces price impact and typically gives you a better rate.

When you have Best Price selected in your swap preferences (the default), Swaptain automatically uses streaming swaps when they provide a better rate.

Key Properties

• Native assets — You receive real BTC, ETH, AVAX, etc. Not wrapped or synthetic versions
• Decentralised execution — No single entity can censor or reverse your swap once submitted
• Deterministic pricing — Rates are determined by pool depths using the Continuous Liquidity Pool (CLP) model
• Automatic routing — Swaptain finds the best route across all available pools
• Slippage protection — Your configured slippage tolerance (default 3%) protects against excessive price movement

Swap Preferences

Swaptain offers two execution modes, configurable in your Settings:

| Mode | Behaviour | |------|-----------| | Best Price (default) | Uses streaming swaps for optimal execution. May take slightly longer | | Fastest Execution | Prioritises speed over price. Single-swap execution |