halkyon/halkyon_learn_server/README.md

# halkyon_learn_server

This is the starting point for your Serverpod server.

Start your server by running:

    cd halkyon_learn
    serverpod start

When you are finished, you can shut down the running server with `Q`.

## Dictionaries

The dictionaries people look words up in (JMdict, …) are reference data the
server holds for everyone. They come as dictionary files, which
`halkyon_learn_curator` makes from the sources' downloads (its README says how).
At every start, and daily at 04:07, the server loads the files in its
`dictionaries` folder that changed since they were last loaded (by their
SHA-256): in the background, a source at a time, and all at once, so searches
meanwhile still find the old entries. A file it can't read is logged and left
out. `DICTIONARIES_DIR` names another folder.

EDRDG's licence asks a server showing its dictionaries to update them at least
once a month:

- **An instance** keeps them current by itself: the `dictionaries` service in
  `deploy/compose.yaml` (the curator, in a container of its own) downloads
  EDRDG's files of the day once its files are a week old, converts them, and
  replaces them in a volume the server reads (`curate update`, the curator's
  README); the server takes them up the next morning. To supply files yourself
  instead, remove the service and mount `deploy/dictionaries/` into the server
  (`compose.yaml` says how), and update them monthly.
- **Development:** `dart run halkyon_learn_curator:curate update --into
  ../halkyon_learn_server/dictionaries` in the curator's folder (about a
  minute), then restart `serverpod start`, or wait for the morning.

JMdict in English, with the JLPT levels and Tatoeba's example sentences, is
about 20 MB gzipped and takes the server half a minute to load (219,000
entries). KANJIDIC2 in English, with the JLPT levels of the kanji and the kana,
is a dictionary of characters beside it (`kanjidic-en.jsonl.gz`, 0.7 MB,
12,800 entries): the app's Kanji & kana tab. Their licences (CC BY-SA 4.0;
CC BY 2.0 FR for the sentences; CC BY for the JLPT lists) ask for attribution:
the app lists the credits each file carries.

## Licence

Copyright (C) 2026 The Halkyon Learn contributors

Licensed under the Server Side Public License, version 1 (`SSPL-1.0`); the full text
is in `LICENSE`.