Local Metadata Databases
Getting metadata and building ComicInfo.xml files for a large collection through an online API is slow — you're bound by rate limits and network round-trips. CLU can instead read metadata from a local SQLite database stored on your own disk, which is dramatically faster for bulk-updating a big library and has no API rate limits.
Two local databases are supported:
| Database | What it is | Setup |
|---|---|---|
| Grand Comics Database (GCD) | A SQLite dump you download from comics.org. | GCD SQLite Setup |
| ComicVine (Local DB) | A prebuilt SQLite copy of ComicVine data. | ComicVine Local DB Setup |
SQLite replaces MySQL in v6.0
Earlier releases required running a separate MySQL container for local GCD data. As of v6.0 that's gone — both local databases are now single SQLite files that CLU reads directly from disk. There's no separate database server, no Docker network, and no import step to run.
How it works
Both databases follow the same pattern:
- Download the SQLite file and place it somewhere mapped into the CLU container.
- In Settings → Metadata Providers, enter the file's full path in the provider's Database Path field.
- Save and Test — CLU reads the file directly from disk (nothing is uploaded).
- Enable the provider for the libraries where you want to use it.
A snapshot in time
A local database is a snapshot from the day you downloaded it — it won't contain comics released after that date. This is ideal for bulk-updating your back catalog; pair it with an online provider (Metron or the ComicVine API) to cover brand-new releases.