Hi Gogo!
You can't add your own NPM package to Botpress at the moment, so no Langchain integration, however we do include the Axios library so you can call the OpenAI api using the Execute Code card for full control.
You will be able to chain prompts in Botpress directly using a few execute code cards.
The open source license for Botpress v12 is an AGPL-3.0 license.