Engine (Solver)

The Engine acts as the neutral coordinator that turns incoming intents into executable swaps.

Responsibility	Detail
Intent Intake	Receives validated swap or limit‑order intents from DotSwap Server.
Route & Quote	Aggregates curves from all active Makers, selects the best path, and produces a draft PSBT with embedded slippage guard.
Signature Relay	Dispatches the PSBT to each Maker for partial signature, then returns it to the Taker for final sign‑off.
Broadcast & Trace	Broadcasts the fully signed transaction, monitors confirmations, and updates UTXO/curve states across the network.

Flow Snapshot

1. Intent → Engine

2. Quote → PSBT draft

3. Maker Sigs → collected

4. Taker Sig → finalised

5. Broadcast → status streamed back

The Engine never holds user funds; it simply choreographs a deterministic signature dance that ends in an on‑chain swap.