Tessel

English | 简体中文

Tessel is a local-first PDF reader for focused reading, contextual AI conversations, translations, notes, and page workspaces.

Features

• Contextual reading — select a passage, quote it into a conversation, translate it, or turn it into a note.
• Persistent PDF workspace — reading progress, bookmarks, highlights, conversations, translations, notes, and pinned items stay attached to the PDF content hash.
• Codex integration — optionally use a locally installed Codex CLI for chat, translation, document search, local tools, images, and LaTeX output.
• OpenAI-compatible providers — route chat, translation, and generated outlines through an OpenAI-compatible API when preferred.
• Page whiteboards — place pressure-aware vector canvases beside PDF pages with pens, colors, undo, and lasso selection.
• Tablet handwriting over LAN — open the whiteboard link from Settings on a tablet. Write with a stylus, scroll continuously with one finger, and zoom with two fingers. Brush and finger-writing preferences carry across sheets.
• Local-first storage — PDF files remain in their original locations; Tessel stores metadata and derived content in Electron's userData directory.
• Optional WebDAV sync — synchronize reading progress, conversations, notes, and translations across devices.
• Desktop releases — installers are published for Windows and macOS through GitHub Releases.

Download

Download the latest installer from the latest release.

Windows releases support in-app update checks and installation. Unsigned macOS builds are updated manually: download the latest DMG or ZIP and replace the existing application.

Run from source

Requirements: Node.js 22 and pnpm 11.

corepack enable
pnpm install
pnpm dev

Build and verify the desktop application:

pnpm build
pnpm test:e2e

If the shell has ELECTRON_RUN_AS_NODE=1, remove it before starting Electron.

AI providers

Tessel can use an OpenAI-compatible provider configured in Settings. API keys are protected with Electron safeStorage when the platform provides it.

The optional Codex integration requires a locally installed and authenticated codex CLI. If Codex is unavailable, the PDF reader and provider-based features remain usable.

Codex chat and translation reuse a background process. Translation uses a compact text-only context and a fast available model unless configured otherwise. Built-in PDF tools reuse parsed documents and page text; CLI compatibility mode receives the same tools through a temporary local MCP connection, without requiring pdftotext. File citations, local images, fenced code, and LaTeX render directly in messages.

Data and privacy

Tessel stores its workspace in Electron's userData directory. It contains PDF metadata, reading state, conversations, translations, notes, pins, and preferences. PDF files themselves remain in their original locations. Optional WebDAV sync is disabled until configured by the user.

See Release Notes for the current release details.