Super cool concept - as someone who is just learning Python I've found Jupyter to be a great way to code and debug live. But yea it's hard for me to share that with someone as a beginner coder - are you planning on having this be a paid feature?
Mercury will be open source. I plan to create a cloud service for easy deployment. There will be free and paid tier. Mercury is AGPLv3. You can buy commercial friendly license as well.