Storage and config

Settings save themselves with the player’s profile. For anything else your addon keeps (waypoints, a list of finds, a cache), use your own folder: ctx.storage(), at .minecraft/myriad/addons/<your mod id>/.


public final class WaypointStore {
    private static final String FILE = "waypoints.json";
    private static final int VERSION = 2;
    private final AddonStorage storage;
    private final Map<String, BlockPos> waypoints = new LinkedHashMap<>();
 
    public WaypointStore(AddonStorage storage) {
        this.storage = storage;
    }
 
    public void load() {
        storage.readJson(FILE, VERSION, WaypointStore::upgrade).ifPresent(json -> {
            for (var e : json.getAsJsonObject().entrySet()) waypoints.put(e.getKey(), BlockPos.of(e.getValue().getAsLong()));
        });
    }
 
    public void save() {
        JsonObject o = new JsonObject();
        waypoints.forEach((name, pos) -> o.addProperty(name, pos.asLong()));
        storage.writeJson(FILE, o, VERSION);
    }
 
    /** Older data, one version step at a time. */
    private static JsonElement upgrade(int from, JsonElement data) {
        if (from == 1) { /* version 1 kept a list: turn it into a map */ }
        return data;
    }
}

`AddonStorage`
`readJson(name)`, `writeJson(name, json)`	plain JSON files
`writeJson(name, json, version)`, `readJson(name, version, upgrade)`	versioned: older data is brought up to date step by step on read
`directory()`	the folder, for files of your own format

Writes are atomic (a crash mid-write can’t corrupt the file), and the first write each session keeps a .bak.

How Myriad saves

Module settings and states, control panels and the menu layout belong to the active profile (profiles/<name>/). Your module’s settings switch with it, for free.
Only values that differ from the defaults are saved, so a better default in an update reaches everyone who never changed it.
Saved settings a module doesn’t know (from a newer or older version) are kept on save; entries of addons that aren’t installed are kept too.
Myriad.config() is the config manager: activeProfile(), profiles(), switchProfile(name), markDirty() (save soon), saveNow().