# SDK Overview

Routing Engine SDK is a TypeScript/JavaScript client for **Zert's routing API**. Use it in front-end or back-end apps to discover chains/tokens/pairs, request quotes, run the swap signing flow, manage limit orders, and check transaction/system status.

The SDK talks only to Zert's backend at a fixed URL (`DEFAULT_API_BASE_URL` from the package; no runtime `baseURL` override). Pass **`api.apiKey`** so every request includes the **`x-api-key`** header. You can also set timeout, `baseHeaders`, and `onError`.  It exposes a layer-based API (`sdk.swap.build()`) and flat methods (`sdk.buildSwap()`).

## Documentation

* [SDK Overview & Configuration](/routing-engine-sdk/installation-and-configuration.md) — Install, configure, and get started.
* [Get Supported Chains](/routing-engine-sdk/get-supported-chains.md) — Fetch supported chains.
* [Token Management](/routing-engine-sdk/get-available-tokens.md) — Fetch available tokens.
* [Get Trading Pairs](/routing-engine-sdk/get-trading-pairs.md) — Fetch trading pairs.
* [Request a Quote](/routing-engine-sdk/request-a-quote.md) — Request a quote for a swap.
* [Submit a Swap](/routing-engine-sdk/submit-a-swap.md) — Submit a swap.
* [Limit Orders](/routing-engine-sdk/limit-orders.md) — Create, get, cancel, and list limit orders.
* [Status](/routing-engine-sdk/sdk-overview.md) — Get transaction status.
* [Health](/routing-engine-sdk/check-service-health.md) — Check service health.
* [Error Handling](/routing-engine-sdk/error-handling-for-apis.md) — Handle API and SDK errors.

## Routing Engine SDK features include

* **Discovery endpoints** - Fetch supported tokens, chains, and tradeable pairs.
* **Quote and swap flow** - `POST /quote`, then build/sign/submit via 3 swap endpoints.
* **Limit orders** - Create, get, cancel, replace, and list limit orders.
* **Status and health** - Check transaction status and service health.
* **Optional configuration** - `timeout`, `baseHeaders`, and global `onError` (fixed backend host; exports include `DEFAULT_API_BASE_URL` and `API_KEY_HEADER`).
* **Two API styles** - Layer-based methods (`sdk.swap.build()`) or flat methods (`sdk.buildSwap()`).
* **Typed and promise-based** — Full TypeScript types and consistent Promise-based async API.


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