DEVONthink 4.3 Herschel* is the third feature release for DEVONthink. It introduces its own MCP server, a bridge from your databases to compatible AI apps like Claude or Codex. Comprising almost 60 commands, we built it with data privacy and security at its core: you control local and remote access, and it redacts private information before it leaves your machine, honors items excluded from AI, and blocks direct filesystem access to your database internals.
A menu bar icon appears whenever its HTTP server is running, giving you quick access to server controls, settings, and the URL you need to connect. And because some databases should simply never touch an AI, the Exclude from Chat & MCP option lets you exclude entire databases at once — enabled automatically for encrypted and revision-proof databases.
Beyond the MCP server, DEVONthink 4.3 Herschel brings sweeping AI improvements. The chat assistant now redacts more sensitive information, e.g., phone numbers, credit card numbers, authentication tokens, and labeled secrets, before anything is sent to a language model, a protection that extends to AI smart actions and summarize and transform functions. It supports the Apple Intelligence Foundation model for simple tasks, and you can choose which AI model handles automatic tagging. We have also updated numerous AI models, including Claude Opus 4.7, GPT 5.5, Gemini 3.5 Flash, Mistral Small 4 and Medium 3.5, Flux 2, and many OpenRouter models.
Replacing MultiMarkdown, our new Markdown parser and renderer supports callouts, citations, captioned tables, and improved CriticMarkup. It is also more compatible with AI-generated output. Markdown documents know about smart quotes and dashes, and converting them to plain text strips all formatting and renders MathJax in readable form.
Finally, new desktop widgets for macOS Sequoia and later let you quickly view or access your Reading List or Favorites, load a workspace, or read the useful tips we regularly publish on our blog. For Server users, the web interface gets a dialog for opening provided item links and lets you reveal, move, duplicate, and replicate items from the context menu. The See Also inspector has a new section for classifying documents, and we have rebuilt the PDF viewer with a table of contents, page thumbnails, and full-text search across all browsers.
*) We name this release after the periodic comet 35P/Herschel–Rigollet, discovered in 1788 by Caroline Lucretia Herschel (1750–1848). Caroline was the sister of the famous astronomer William Herschel and made significant contributions to astronomy in her own right. She discovered eight comets and numerous nebulae and star clusters, and compiled an influential catalogue of deep-sky objects. Caroline Herschel was the first known professional female astronomer, became the first woman to receive a salary as a professional astronomer, and received the Gold Medal of the Royal Astronomical Society.
