ERP archives ​

F1 25 stores most artwork and track assets in .erp files under 2025_asset_groups/. Each archive contains named resources, split into one or more parts called fragments.

To change an asset in a mod, see ERP operations.

Tools ​

  • packages/formats/src/erp.rs: Rust reader and writer.
  • tools/erp.py: inspect and extract resources.
  • tools/erpw.py: rebuild archives.

List resource names:

sh
python3 tools/erp.py <archive> '*'

Writing rules ​

Keep unchanged fragments as stored. For changed fragments, update their sizes, compression and resource hash. Rebuilding an unchanged archive should produce identical bytes.

UI resources inside ERPs use the !pkg format.

Test ​

sh
F1_25_DIR="/path/to/F1 25" cargo test -p swofty-formats

This checks real game files when F1_25_DIR is set.