Twenty

Twenty is an open-source CRM built for modern revenue teams that want the flexibility of a custom internal tool without giving up the polish of a packaged product. It ships with the standard companies/people/opportunities objects, but every record type is fully customisable — you can add fields, relations and views the way you would in Notion or Airtable, while still getting pipeline boards, inbox-style email sync, calendar sync and an activity timeline out of the box. A native AI assistant works across records to draft outreach, enrich contacts, summarise account activity and trigger workflows; the workflow engine itself is a visual canvas where teams can chain CRM events, HTTP calls, webhooks and AI steps without code. Twenty is GraphQL- and REST-API-first, with a self-hostable Docker stack and a cloud edition for teams that don't want to operate it. Because it's source-available under the AGPL, growth and RevOps engineers routinely fork it for industry-specific verticals (PE, recruiting, marketplaces) instead of paying per seat for entrenched incumbents. It is one of the fastest-growing OSS CRMs on GitHub and has become a popular reference point for teams evaluating Salesforce or HubSpot replacements in 2026.