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Data Storage

FindRomCover keeps configuration and caches in %LocalAppData%\FindRomCover and writes logs and its MAME database next to the executable. This page lists every file, what it contains, and how long it is kept.

Data folder

Default location: %LocalAppData%\FindRomCover (typically C:\Users\<you>\AppData\Local\FindRomCover).

File Format Purpose Retention
Settings.dat SQLite All settings, including encrypted API keys Until deleted
QueryHistory.dat SQLite Covers already queried with AI Assist 180 days, max 100,000 entries
ai-cache.json JSON Cached AI verdicts 30 days, max 2,000 entries
ai-models.json JSON Cached model lists per provider and base URL 7 days
settings.dat.legacy Encrypted legacy file Backup of the pre-SQLite settings file Until deleted

Application folder

These files live next to FindRomCover.exe:

File Purpose
mame.dat MAME game database used for descriptions
app.log Rolling application log
error.log Error-level log
error_user.log Simplified error list for user reference
settings.dat.legacy Legacy settings backup after migration (if migrated from the app folder)
settings.dat.corrupt Quarantined settings database that could not be read

Settings database

Settings.dat is a SQLite database with a simple key/value table:

CREATE TABLE Settings (
    Key   TEXT PRIMARY KEY,
    Value TEXT NOT NULL
);

Every setting is stored under its property name, for example BaseTheme, SimilarityThreshold, AiProvider, AiModel. List values such as SupportedExtensions are stored as JSON arrays.

Encryption

Sensitive values are encrypted with AES using a machine-derived PBKDF2 key before they are written:

  • GoogleKey
  • AiApiKey
  • BugReportApiKey

Other values are stored in clear text inside the database. The database itself is not encrypted, but secrets in it are.

Migration from older versions

When FindRomCover starts and Settings.dat is not a SQLite database, it assumes the old encrypted settings format and:

  1. decrypts the file;
  2. applies every setting it contains, including API keys;
  3. writes the settings to the new SQLite database;
  4. renames the old file to settings.dat.legacy as a backup.

The same migration runs for an old settings.xml, which is also moved aside after conversion. If the legacy file cannot be decrypted, it is preserved as a backup and defaults are used instead. If a SQLite database is corrupt, it is renamed to settings.dat.corrupt and defaults are restored.

Query history database

QueryHistory.dat uses non-pooled SQLite connections, so the file is never held open:

CREATE TABLE QueryHistory (
    TargetPath TEXT PRIMARY KEY COLLATE NOCASE,
    QueriedUtc TEXT NOT NULL,
    Outcome    TEXT NOT NULL
);

Entries older than 180 days are removed, and the table is trimmed to 100,000 rows when it grows beyond that. See Query History.

Caches

Cache Key What is stored
ai-cache.json Game and candidate set AI verdicts, including confidence and choice
ai-models.json Provider and base URL The list of models returned by the provider

Both caches are best-effort: deleting them only means the next request is slower or costs a little more.

Backing up and restoring

Backup

  1. Close FindRomCover.
  2. Copy the whole %LocalAppData%\FindRomCover folder.

Restore

  1. Close FindRomCover.
  2. Replace the folder with your backup.
  3. Start FindRomCover.

Caution: Settings encryption is tied to the Windows user and machine. A settings database copied to a different user account or PC may not be decryptable, and API keys would need to be entered again.

Cleaning up

Goal Action
Free space Delete ai-cache.json and ai-models.json
Reset query history Use Clear query history in AI Settings, or delete QueryHistory.dat
Full reset Delete Settings.dat (also removes stored API keys)
Remove legacy backups Delete settings.dat.legacy and settings.dat.corrupt