Yeah they definitely belong in the same space. Nexus is an LLM Gateway, but early on, the focus has been on MCP: aggregation, authentication, and a smart approach to tool selection. There is that paper, and a lot of anecdotal evidence, pointing to LLMs not coping well with a selection of tools that is too large: https://arxiv.org/html/2411.09613v1
So Nexus takes a tool search based approach to solving that, among other cool things.
Disclaimer: I don't work on Nexus directly, but I do work at Grafbase.
Here are a few key differentiators vs LiteLLM today:
- Nexus does MCP server aggregation and LLM routing - LiteLLM only does LLM routing
- The Nexus router is a standalone binary that can run with minimal TOML configuration and optionally Redis - LiteLLM is a whole package with dashboard, database etc.
- Nexus is written in Rust - LiteLLM is written in Python
That said, LiteLLM is an impressive project, but we're just getting started with Nexus so stay tuned for a steady barrage of feature launches the coming months:)
The main difference is that while you can get Nexus to list all tools, by default the LLM accesses tools by semantic search — Nexus returns only the relevant tools for the what the LLM is trying to accomplish. Also, Nexus speaks MCP to the LLM, it doesn't translate like litellm_proxy seems to do (I wasn't familiar with it previously).