Today, CSV export is the only integration. You can export your saved board to CSV and import it into whichever CRM you use.
There's no API at the moment. If you were planning to pull data out programmatically, CSV export is the route for now.
Two-way CRM integrations with Salesforce and HubSpot are being built, so data will be able to move in both directions. We don't have a date to share yet.
Using something else — Acumatica, Pipedrive, Dynamics? Message us here in chat and tell us which CRM you're on. We log every request, and what customers ask for shapes what we build after Salesforce and HubSpot.