Simply Nexus
A Rust-native VST3 / CLAP plugin host: one engine that loads and plays plugins, a standalone app, and a headless MCP server for AI agents.
Nexus is built in layers. The foundation is a format-agnostic hosting engine that loads and runs VST3 and CLAP plugins behind a single interface. A standalone app drives that engine today; the next layer reuses it as a plugin-that-hosts-plugins.
Goals
One interface, two formats
Callers never branch on VST3 vs. CLAP — the host abstracts the difference away.
Reusable core
The hosting engine is a library every layer depends on, so there is exactly one implementation of plugin loading and processing.
Wrap anything
The engine ships as nexus-wrap, a plugin that hosts another plugin — so anything Nexus can load can run, wrapped, inside any DAW.
Programmable state
An MCP interface for inspecting and controlling a wrapped plugin's saved state.
For AI agents: headless, no audio driver
A dedicated standalone binary, nexus-mcp, is built for AI agents (Claude Code, Claude Desktop, Cursor). It runs completely headless — no GUI windows, no audio interface — so an agent can autonomously discover, load, configure, perform and sample arbitrary VST3 and CLAP plugins, and render the result offline.
The crates
nexus-host- The engine that discovers, loads and runs VST3/CLAP plugins. Fast offline rendering without audio drivers.
nexus-tools- Transport-agnostic tool traits, registry, state codecs, snapshot store, main-thread bridge.
nexus-mcp- Standalone MCP server exposing every tool to AI coding agents over stdio or streamable HTTP.
nexus-rest- In-process REST API and a browser-based debug UI.
nexus-app- Standalone GUI host: egui UI, CPAL audio out, MIDI in, plugin browser and editor windows.
nexus-wrap- A VST3/CLAP plugin that itself hosts another plugin.
Get it
Nexus is open source under the MIT license. Clone it, cargo build --release, and the README walks through the MCP setup for stdio and HTTP.