Yes, similar ideas. Marvin [asks the LLM to mimic the python function](https://github.com/PrefectHQ/marvin/blob/f37ad5b15e2e77dd998...), whereas in magentic the function signature just represents the inputs/outputs to the prompt-template/LLM, so the LLM “doesn’t know” that it is pretending to be a python function - you specify all the prompts.