DeepSeek Harness allows the user/agent to build its own plug-ins and run them without restart, mostly. Pi and OpenCode were then influenced to do the same in their respective new versions. I don't know which has the better implementation.

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

I do not see where Pi does any automatic hot-reloading, though I believe there is a /reload command one has to run that can do this. Still new to Pi, if you have a link, I'd be appreciative.

This is all a stopgap until I have some time to go back to my personal/custom harness.