Integrations are self-contained plugins discovered from the filesystem at startup. No packaging, no entry points, no edits to core files, no frontend changes: configuration UI is rendered from the manifest's schema.
A manifest can declare an admin credential schema, a per-user connection, service entries with endpoint allow-lists, system skills, tools, and action-request handlers. Plugins inherit the security model; public projects always block them. The in-tree github and twitter plugins are the reference, and QUEST_PLUGIN_PATH loads external roots so a fork can keep proprietary integrations out of tree.