> ## Documentation Index
> Fetch the complete documentation index at: https://onr.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Why ONR

> What ONR is and why the DSL-first approach matters.

Open Next Router (ONR) is a lightweight, DSL-driven LLM gateway that routes requests, applies explicit compatibility transforms, and normalizes behavior across providers and channels.

## Core benefits

* Atomic, nginx-like DSL: behavior is declared in DSL loaded from `config/onr.conf`, typically including files under `config/providers/*.conf` (see [config/onr.conf](https://github.com/r9s-ai/open-next-router/tree/main/config/onr.conf)).
* Fast provider onboarding: patch quirks by editing `.conf`, not changing code.
* Hot reload: reload `onr.yaml` / `keys.yaml` / `models.yaml` / `config/onr.conf` and included DSL files via SIGHUP.
* No hidden magic: transforms are opt-in via directives (for example `req_map`, `resp_map`, `sse_parse`).
* Streaming-aware normalization: handle SSE framing and provider streaming semantics.
* Operational visibility: one-line logs with optional usage/cost extraction.