xOpat — Explainable Open Pathology Analysis Tool

^{A web-based whole-slide imaging framework — not a viewer, but the viewer you configure to your use-case.}

⚠️ This is xOpat v3 — an alpha release. The older but stable v2 line lives on the archive/v2 branch. If you experience anny issues, please, let us know.

What is xOpat?

Whole-slide imaging produces massive, complex data — scans and derived outputs in both vector and raster form — that are hard to work with efficiently. Patent restrictions and competing standards have fragmented the landscape into many ad-hoc open-source and proprietary tools. That diversity creates friction: clinicians face legacy systems and economic constraints; researchers juggle incompatible platforms and unwieldy data scales. And the viewer — the direct interface to all of it — usually bakes in one platform's API, forcing institution-wide, multi-petabyte decisions on the basis of viewer features that are often orthogonal to actual viewing needs. The result is cascading lock-in that can be impossible, or economically unjustifiable, to undo.

xOpat takes a different stance: it is not a viewer, it is a viewing framework. Rather than hardwiring an API or a deployment model, it adapts through modules, plugins, and deep configuration flexibility — letting you assemble a tailored interface for clinical, research, or educational use without committing your infrastructure to anyone's platform. The OpenSeadragon feature driver, and author of the Flex Render renderer, it is server-agnostic, modular, and extensible solution.

We run it across very different environments — closed-source infrastructures, custom data backends, ad-hoc configurations, Jupyter Notebook & Google Colab workflows, local desktop viewing, Kubernetes-scale deployments, and more.

What it gives you

• 🔌 No hardwired backend. Connect to any WSI image server that speaks a protocol xOpat can resolve — add support for your own with a single file.
• 🗂️ Vector and raster overlays. Photoshop-style visualization layers (WebGL shaders) and versatile annotations over the same slide.
• 🧩 Plugins & modules. OIDC auth, AI chat assistants, visualization storytelling, tutorials, ICC profiles, action shortcuts, and more — load only what a deployment needs.
• ⚙️ Static and runtime configuration. Shape the whole experience from env.json down to per-session URLs.
• 🖥️ Run it your way. Node.js server, PHP server, or server-less — compiled once and served as static files.

What xOpat is not

It is not an all-in-one product. xOpat does not read WSI formats itself and does not run your AI — but it connects to the servers and services that do. If an image server can read your slides, xOpat can show them; AI results arrive as raster images (like any slide) or as vector graphics. Add a plugin to wire up whatever else you need.

Get started

📚 Full documentation: https://xopat.org  ·  🔎 API reference: https://xopat.org/api/

Sponsors

We are grateful for the development and financial contributions supporting xOpat and the OpenSeadragon project.