> For the complete documentation index, see [llms.txt](https://docs.nexus.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nexus.xyz/apis-and-rates.md).

# APIs & Rates

- [APIs & Rates](https://docs.nexus.xyz/apis-and-rates/apis-and-rates.md): The REST and WebSocket gateway — base URL, authentication, and the rate-limit model.
- [Exchange REST](https://docs.nexus.xyz/apis-and-rates/apis-and-rates/exchange-rest.md): The REST surface at a glance: authentication and keys, account, orders, market data, and stats.
- [Exchange Websocket](https://docs.nexus.xyz/apis-and-rates/apis-and-rates/exchange-websocket.md): Real-time order book, trade and account streams — subscriptions, tokens, and reconnection.
- [Rate & Connection Limits](https://docs.nexus.xyz/apis-and-rates/apis-and-rates/rate-limits.md): Weight-per-second budgets, the three independent buckets, and the per-tier ceilings.
- [Market Maker Guide](https://docs.nexus.xyz/apis-and-rates/apis-and-rates/market-maker-guide.md): Quoting on the Exchange: post-only, cancel-on-disconnect, rate-limit tiers, and maker rebates.
- [API Versioning](https://docs.nexus.xyz/apis-and-rates/apis-and-rates/api-versioning.md): How the API is versioned, which version a client is served, and how a deprecation is signalled.


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