Meet libscid: Scid’s Backend as a Library

Updated: 2026-10 Published: 2026-10

I’ve been using Scid since 2012, and I cannot imagine chess without this incredibly rich piece of software!

I also do a lot of batch analysis of games. And, for years, that meant working on PGN files and then manually importing the games into my Scid databases. I wanted to script that work and have my own tools interact directly with the database.

Scid had so much of what I needed already. The difficulty was getting at it from outside the application.

A Rich Monolith

I also wanted to see a modernised Scid. In 2024, I started toying with the idea of tackling the technical debt in its codebase. My first concern was documenting its existing behaviours through tests, before touching the implementation.

Only in 2025 did I find the time to pick up the work seriously. The result was ScidUp: plenty of tests, ancient features trimmed, and a reorganised codebase.

But it was still a monolith. A rich one, with a tremendous amount of useful chess functionality, but still a monolith. Improving the whole thing as one unit felt increasingly difficult.

That was when I decided to separate the application side from the backend side.

Making the Application One of the Users

The backend needed to become an independent library, with ScidUp as one of its users. That would give the chess functionality its own boundary, and let the application concentrate on how people interact with it.

It would also give other programs a way in. The same underlying work could support a batch-processing tool, an analysis script, or a different application altogether.

That separation became libscid.

There is a great deal of knowledge and experience accumulated in Scid. Handling chess games and their variations, working with game archives, and keeping databases useful are all problems that its contributors have spent years solving.

I wanted to preserve that work and make it easier to build on. The tests helped document the behaviours I was working with; separating the library gave those behaviours a home outside the desktop application.

For me, the appeal is both practical and exploratory. I want more freedom to automate my own chess work, and more room to improve the software I rely on. Making the backend independently usable opens that room to other programmers, too.

Take a Look

If you write chess software or automate parts of your chess work, have a look at the project and documentation. There are guides for using the library through its C interface and Python bindings.

The source is on GitHub, under the GNU GPL v2. It carries forward the legendary work of Scid’s contributors, alongside the changes that grew out of ScidUp and the extraction into a library.

Bahman's Musings