Theca interface tour
Updated on August 5, 2026
Theca has four main areas, all reachable from the left sidebar. Here is what each one does and how to get there.
Library
Library is the home screen. It shows all your books in a grid or list view; switch between them using the view mode control in the toolbar. You can sort by Title, Author, Date added, Last read, Pages, or Size, and filter by typing in the Filter... field.
Each book has a status indicator: Processed, Processing, Queued, Error, or others. Only books with the status Processed appear in search and in AI Mode.
Click a book to open its detail panel on the right. From there you can read it, download it, delete it, or see a quick summary if one has already been generated.
Book detail panel
Selecting a book in the Library opens the Book details side panel. It shows your reading progress, metadata (format, pages, size, language), any tags you have added, and the available actions:
- Read — opens the reader.
- Process — indexes the book for search (appears if the book has not been processed yet).
- Download — downloads the original file.
- Delete — removes the book from your library.
If the book has a generated summary, the panel also shows it in compact view with a link to Show all N points in full.
Reader
The reader opens when you click Read in the detail panel or double-click a book. From the toolbar you can:
- Navigate with Previous page and Next page, or switch to Scroll mode for continuous scrolling.
- Switch to Dual page to view two pages side by side.
- Zoom in or out with Zoom in and Zoom out.
- Highlight selected text with Highlight and choose a color with Highlight color.
- Enter Fullscreen for a distraction-free reading experience.
- Return to the Library with the Back to library arrow or by pressing Escape.
The reader remembers the page where you left off and restores it the next time you open that book.
Search
Click Search in the sidebar to go to the search screen. Type in the Search your library... field and press Enter. You can adjust the scope:
- Whole library — searches across all your processed books.
- Selected books — choose which books to search using the book selector.
Results appear in List view or grouped By Book. Each result has a page preview and an Open here link that jumps directly to that passage in the reader.
When AI Mode is on, an AI overview from your sources appears above the results, showing the citations from the passages the AI used to answer.
Search only works with books in the Processed state. If you just uploaded a book, wait for processing to finish.
Summaries
The Summaries section appears in the sidebar only when AI Mode is on. From here you can create a new summary by clicking New summary, select the books to include, define a topic or a table of contents, and let the AI write the summary section by section with traceable citations back to your sources.
Summaries you have already generated appear in the main list; you can open them, download them as PDF, Markdown, plain text, or Word, and generate study cards for EON from them.
Frequently asked questions
How do I get back to the Library from the reader? Press Escape or click the Back to library arrow in the top-left corner of the reader.
Why don't I see Summaries in the sidebar? Summaries only appears when AI Mode is on. Turn it on with the toggle at the top of the interface.
Can I search within a single book? Yes. In the Search screen, change the scope to Selected books and choose the book you want in the selector.
Next step
- Uploading books — more details on how to upload and manage your books.
- Search — advanced search options and available modes.
- Summaries — how to create and use summaries with traceable citations.