Hi @zhun_t. Great question!
You can change the port by setting:
[server]
port=9988
in your ~/.streamlit/config.toml.
Currently, you cannot set the port separately for multiple apps, but you won’t have to wait long! That feature has been implemented and is expected to land in 0.48 which will be released next week. Please follow that issue on Github for up-to-date information.
If you need a workaround right now, you could override ~/.streamlit/config.toml right before launching each server.
By the way, if you’re interested, you can see the full set of config options by running:
streamlit config show
from the command line.