Extend

Overview

Extend UI is an open-source UI kit for document apps, built by Extend. It provides React components for viewing and editing PDF, DOCX, XLSX, PPTX and CSV files, with bounding box citations, file upload, e-signing and schema building, intended for user-facing flows, document agents, human-in-the-loop review and internal tools.

The registry includes 68 items: document viewers and editors, nine full-example blocks, and a base set of UI components built on Base UI. PDF rendering uses the EmbedPDF engine, and the source is published on GitHub at extend-hq/ui.

Features

• PDF viewer and editor: Viewing, editing and a resizable PDF shell, plus a PDF dropzone.
• Office formats: DOCX viewer and editor, XLSX viewer and editor, Excel editor, PPTX viewer and CSV viewer.
• Bounding box citations: Highlight the source region of extracted data on a document.
• Document splits: Components for showing how a file is divided into sub-documents.
• Schema builder: Define extraction schemas in the UI.
• E-signature: Signing component for documents.
• File system and upload: File system browser, file thumbnails and file upload.
• Base components: Accordion, autocomplete, color picker, command, dialog, sidebar, tabs, toast and more.

Tech stack

• React, Tailwind CSS, shadcn/ui, Base UI
• EmbedPDF, pdf-lib

Registry

Install via the shadcn CLI registry:

npx shadcn@latest add @extend/component-name