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wtf is database?

cakiki/database — explained in plain English

Analysis updated 2026-07-18 · repo last pushed 2026-03-13

ScalaAudience · researcherComplexity · 2/5MaintainedSetup · easy

TL;DR

A tool that exports lichess chess games into the universal PGN format so researchers, chess engines, and coaches can study or analyze real games.

Mindmap

mindmap
  root((repo))
    What it does
      Exports lichess games
      Converts to PGN format
      Filters by month variant
    Tech stack
      Scala
    Use cases
      Train chess AI
      Study opening trends
      Browse real games
    Audience
      Chess researchers
      ML engineers
    Access
      Prebuilt files hosted
      Or run tool yourself

Code map

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filefunction / class

Why would anyone build with this?

REASON 1

Download a month of lichess games as PGN files to study opening trends.

REASON 2

Train a chess engine or evaluation model on thousands of real games.

REASON 3

Build an opening repertoire by analyzing what worked in real matches.

REASON 4

Browse interesting games from a specific month without running any code.

What's in the stack?

Scala

How it stacks up

cakiki/databasejanikdotzel/akka-http-quickstart-scalalrytz/play-scala-compile-di-with-tests
LanguageScalaScalaScala
Last pushed2026-03-132023-05-192017-02-09
MaintenanceMaintainedDormantDormant
Setup difficultyeasyeasymoderate
Complexity2/52/53/5
Audienceresearcherdeveloperdeveloper

Figures from each repo's GitHub metadata at analysis time.

How do you spin it up?

Difficulty · easy Time to first run · 5min

Most users just download pre-generated PGN files, running the Scala exporter yourself needs the command line.

Yoink these prompts

Prompt 1
Help me download and open a month of lichess PGN games from this project's hosted files.
Prompt 2
Show me how to run this Scala tool to export lichess games for January 2016.
Prompt 3
Help me write a script to train a simple chess evaluation model on the PGN files from this project.
Prompt 4
Explain the PGN format so I can analyze the lichess game exports from this tool.

Frequently asked questions

wtf is database?

A tool that exports lichess chess games into the universal PGN format so researchers, chess engines, and coaches can study or analyze real games.

What language is database written in?

Mainly Scala. The stack also includes Scala.

Is database actively maintained?

Maintained — commit in last 6 months (last push 2026-03-13).

How hard is database to set up?

Setup difficulty is rated easy, with roughly 5min to a first successful run.

Who is database for?

Mainly researcher.

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