# 6. Developer Guide

### Architecture at a glance

* **SDK (TypeScript):** A lightweight client to request quotes, execute swaps, check tx status, subscribe to updates, and interact with sFund endpoints.
* **Gateway API (Express, REST + WebSocket):** Orchestrates quotes, routes, and transaction lifecycle. Replace the stub logic with your real routing, sequencer, zk-proof, and bridge adapters.
* **Smart Contracts (Solidity):** `SwapRouter`, `CollateralVault`, `SFund` and interfaces for message bridge and zk verifier.
* **UI Demo (React + Vite):** Minimal front-end showing quote → execute flow against the Gateway.



### SDK & API Access:

* Add cross-chain swaps into dApps, wallets, or DEXs.
* Query liquidity pools & optimal routing paths.
* Access live state updates via WebSockets.
* Plug into Splenex collateral engine: tools to integrate Splenex functionality into external platforms.



### Transaction Lifecycle:

1. Request Submitted.
2. Sequencing via PoH.
3. Execution routed across pools.
4. zk-proof generated.
5. Settlement updates global vault.
6. Confirmation across chains: developers can track every stage of execution.\
   \


Developer Hooks:

* Pre-Trade Validation Hook → Confirm route before swap.
* Post-Settlement Hook → For dApp-specific actions.
* Liquidity Pool Access → LP participation + rewards: extensibility points for custom integrations.\
  \
