https://github.com/askmanu/acorn
A straightforward and simple AI agent framework. It puts a lot of emphasis on the loop and the steps in that loop. You can change in real time the model, the temperature, the tools, the history. You're also able to spin-off work on a branch and then add the result of that work on the main branch. Still early but developing very fast.
I notice you mentioned dspy - do you also support prompt optimization?