DeepSeek harness is the OpenCode (better than OpenCode) of the web/desktop medium.

Good things about it are that it is extremely lightweight and fast. The communication between sub agents is two way in that a sub agent can midway send a message to parent and the parent can send a message midway to change the course of action of a sub agent and while this is happening, you can sitll continue talking to the model on the main thread.

Downside of DeepSeek is that it is constantly in flux which is understandable and they make it very clear themselves that the breaking changes are to be expected.