DeepSeek does. The entire thing is composed on plugins, using a framework called Cordis. Everything is a plugin. All the tools, the models, plan mode, file system access, everything. You can change anything anywhere, even reconfiguring active plugins deep internally. Cordis provides an effect system so everything can be rewound on uninstall time. This is how people run local models or just other major models, just by writing a new plugin to talk to whatever instead of the deepseek api. The agent loop itself is a plugin and can be swapped out.

https://github.com/cordiverse/cordis