Theneo

Theneo, built by Y Combinator, Mercury, and Atlassian-backed Theneo Inc., is an all-in-one platform for creating, managing, and sharing API documentation, used by more than 15,000 teams including Ticketmaster and Corpay. It supports real-time collaborative editing with live cursors and presence indicators, AI-powered documentation generation, and an 'Ask AI' tool that gives developers direct answers instead of search results. Theneo integrates MCP Server and llms.txt support for AI agent compatibility, detects breaking changes for intelligent changelogs, and offers private branded customer portals with per-customer access control, markdown and WYSIWYG editing, and version history with audit trails. The Starter plan is free with one public project and up to two private projects; Business is $120/month per workspace with unlimited AI search; Growth is $400/month per workspace for up to 20 developer portals; and Enterprise offers custom pricing with self-hosting and advanced SSO.