This is a plugin that detects when JSON representing an n8n workflow is present in a post, and replaces it with an interactive rendering of the workflow.
git clone https://github.com/discourse/discourse.git
cd discourse
In the Discourse root dir:
d/boot_dev --init
# wait while:
# - dependencies are installed,
# - the database is migrated, and
# - an admin user is created (you'll need to interact with this)
# In one terminal:
d/rails s
# And in a separate terminal
d/ember-cli
cd discourse/plugins
git clone <this repository>
Make sure you also whitelist the domain your iframes are calling in the admin settings of Discourse.