Can registrations sync into the CRM we already use, and is there an API for anything custom?

Yes. EventfullyManaged[1] is designed to connect directly with your existing stack:

CRM & Marketing Sync

• Live Connector: A native connector for HubSpot is available today, allowing you to sync registrations to your CRM so sales teams see new leads and marketing automation can run attendee nurture campaigns.
• Upcoming Connectors: Additional native integrations for providers such as Salesforce, Marketo, and Mailchimp are on the product roadmap.

Review the full details on the Integrations and API use case[2] page.

Custom Workflows & Developer API

For bespoke integrations or systems without an out-of-the-box connector, you can build custom automations using the platform's developer tooling:

• API & Webhooks: Manage event data programmatically and configure outbound webhooks for real-time registration events.
• TypeScript & Node SDK: Typed access to manage events, sessions, registrations, ticketing, and attendees directly from your applications.
• Python SDK: An asynchronous API client built on httpx, ideal for reporting pipelines and data automation.
• CLI & MCP Server: A command-line client for terminal and CI workflows, plus a Model Context Protocol (MCP) server for connecting AI assistants.

To get started with custom development, explore the CLI · SDKs · MCP Ecosystem[3] packages, or consult Professional Services[4] for hands-on migration and integration support.