Extend UI has released an open-source UI kit aimed at modern document workflows, adding a set of React components for viewing and handling common file types inside user-facing apps, agent interfaces, and internal tools.
The library includes components for PDF, DOCX, XLSX, and CSV viewers, along with features such as bounding box citations, file uploads, and e-signing support. The company says the kit is intended to be dropped into product flows without requiring teams to build these interfaces from scratch.
The release reflects growing interest in document-centric AI products, where applications often need to display source files, show where information came from, and let users review or sign documents directly in the interface. Extend UI is positioning the kit as infrastructure for those use cases rather than as a narrow demo or design showcase.
According to the project materials, the components are designed for use in several types of products, including agent experiences and internal business tools. The viewer set covers widely used office and document formats, allowing teams to surface content from PDFs, Word documents, spreadsheets, and CSV files through a unified interface.
One notable feature is support for bounding box citations in document viewers. That capability is relevant for AI applications that need to point users to the exact place in a file where a response was derived, a feature that can improve transparency and make it easier to verify model output.
The toolkit also includes a file upload component that accepts PDFs, DOC and DOCX files, XLSX and CSV spreadsheets, and image formats such as PNG and JPG. That broad support suggests the package is meant to be used as part of end-to-end document handling flows, not just for read-only viewing.
Extend UI also highlights e-signing as part of the package, signaling that the components are meant to support workflows that move beyond simple preview and into approval or completion steps.
Beyond file viewers and upload tools, the project also lists a schema builder component. That tool appears designed for configuring structured form data, including object, array, string, enum, and number properties. In the source material, the builder is shown as a drag-and-drop interface for assembling schemas, which could be useful in applications that collect or validate complex document-related information.
The examples presented with the release also include a file system interface and document split views, indicating that the UI kit covers navigation and organization patterns as well as individual viewers. Together, these components suggest a broader effort to package the most common parts of document application design into reusable open-source pieces.
Extend UI is offering the kit as an open-source project, which could make it easier for developers to customize the components or adapt them to specific product requirements. Open source release models are often used to encourage adoption by lowering the barrier to experimentation and integration.
For teams building AI assistants or enterprise tools that work with contracts, reports, spreadsheets, or other structured files, the new components could help shorten development time. Instead of wiring together separate viewer, upload, citation, and signing interfaces, developers can use a single kit as a foundation.
The release adds to a growing category of UI tooling focused on AI-native document experiences, where the interface needs to support not just content display but also provenance, review, and action. Extend UI is betting that those needs will become a standard part of modern document software.