excali-local

What Excali Local provides offline

Excali Local is a browser extension that brings Excalidraw fully offline. The README describes it as a local first, offline Excalidraw app that lives entirely in the browser. The stated capabilities are screenshot annotation, a complete local editor, a private gallery, and a presentation mode, all with no backend, no account, and no uploads. Every drawing stays in the user's browser, which is the central privacy promise of the project. Excalidraw is a well known whiteboard tool, and Excali Local wraps that experience so it works without an internet connection and without sending anything to a server. The README also links to a Chinese language readme, which shows the project documents itself in more than one language. For a user who handles sensitive diagrams, the offline only design means the content never leaves the machine, removing the trust question that comes with cloud whiteboards. The extension format means it sits inside the browser the user already has, rather than requiring a separate installed application. The README summarizes the value as a complete Excalidraw experience with privacy by default, where annotation, editing, gallery, and presentation are all available locally and the drawings remain under the user's control at all times. The browser extension format means there is no separate server to trust, which is the practical result of the local first design.

Core features and the private gallery

The README lists several features beyond basic drawing. Screenshot annotation lets a user capture a full page or select an area and then annotate it in Excalidraw, which is useful for feedback and documentation. The offline editor is the complete Excalidraw experience with no internet required. The gallery and collections feature lets a user save, organize, search, and manage drawings locally, and it supports exporting or importing everything as a ZIP archive, so work can move between machines or be backed up. Presentation mode turns any drawing into a slide based presentation. Custom fonts let a user upload TrueType, Web Open Font Format, or Web Open Font Format 2 fonts, or use system fonts, which helps match a house style. A later release note adds import of a gallery from a ZIP, so a previously exported archive, even one edited outside the app, can be brought back into the gallery. These features make Excali Local a practical drawing tool rather than a thin wrapper, because the gallery, search, export, and presentation pieces cover the ordinary lifecycle of a diagram from creation to sharing. The README frames the gallery and ZIP import and export as the way users keep ownership of their files.

Collaboration and agent driven editing

Two newer features in the README extend how Excali Local is used. A release note for version 1.8.0 adds realtime collaboration through hostless, end to end encrypted rooms over a relay the user deploys themselves, described as a roughly 150 line PartyKit reference. The README is explicit that there is no Excali Local backend, and the relay only forwards ciphertext, so team rooms are end to end encrypted to the organization and private rooms are end to end encrypted per room, with file sync included. This design keeps the offline privacy model even when people collaborate, because the relay cannot read the drawing. A separate release note for version 1.7.0 adds agent driven editing, where a CLI or an AI agent drives the active canvas through the excali-local skill and the excali-bridge daemon over a local only WebSocket. The README links a collaboration guide and an architecture decision record for the bring your own relay design, plus an agent bridge guide. These additions show the project moving from a solo offline tool toward something teams and agents can use, while preserving the no backend, local first stance through self deployed relays and local only bridges. The README links a collaboration guide and an architecture decision record so a user can inspect how the encrypted relay is meant to work.

Licensing and extension model

The README states Excali Local is published under the MIT license, a permissive license that lets users run, modify, and redistribute the code with minimal obligations. The project ships as a browser extension, which the README presents as the delivery format that keeps everything in the browser with no separate server. The agent driven editing path depends on two named pieces: the excali-local skill and the excali-bridge daemon, connected over a local only WebSocket, which means an AI agent can manipulate the canvas without that control leaving the machine. The collaboration path depends on a user deployed relay using a PartyKit reference implementation, so the encryption keys and relay stay under the user's control. The README's repeated emphasis on no backend, no account, and no uploads is the through line that ties the licensing, the extension format, and the collaboration design together: the user owns the data, the keys, and the relay. For someone evaluating the tool, the practical facts are that it is a TypeScript browser extension under MIT, it works offline, it can sync through a self hosted encrypted relay, and it can be driven by an agent over a local WebSocket. The README supports each claim with a linked guide or decision record.

Editorial conclusion

Excali Local is written in TypeScript and published under the MIT license. The README notes agent driven editing through an excali-local skill and an excali-bridge daemon over a local WebSocket.