Configuration Data Storage

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

Related pages

• Settings Overview
• Query History
• Logs & Diagnostics