There is an HTTP API server, which call plugin APIs. There is a createPage API.
Documentation of the API server
-
https://docs.logseq.com/#/page/local%20http%20server
Plugin API documentation -
https://plugins-doc.logseq.com/logseq/Editor/createPage
https://plugins-doc.logseq.com/logseq/Editor/deletePage
With that, you can interact with your graph from external applications.