Foolbox

Foolbox 3.3.4 is an EagerPy-based library for generating and evaluating adversarial examples against image classifiers. Use this skill when a task mentions Foolbox, foolbox, adversarial examples, robust accuracy, attack budgets, LinfPGD/FGSM/DeepFool/BoundaryAttack, model wrappers, or Foolbox model-zoo repositories.

Command, cache, and output paths

The commands in this skill use the generated skill root, not the native Foolbox checkout and not the caller's current directory. From any cwd, set the root to the directory containing this SKILL.md and change into it before running a command that uses a relative skill path:

# Replace this non-executable placeholder with the absolute directory containing this SKILL.md.
export SKILL_ROOT=/path/to/installed/skills/disco/foolbox
cd "$SKILL_ROOT"

Use the actual installed skill-root path if it differs from the example above. The root scripts/ and sub-skills/ paths below are relative to SKILL_ROOT; an absolute path such as python "$SKILL_ROOT/scripts/smoke.py" is equivalent. Write generated plots and other artifacts only to an explicit absolute path or to a dedicated directory such as "$SKILL_ROOT/outputs/" (create it first); do not rely on an unspecified cwd and do not write into the native checkout or the skill's source/reference assets. Foolbox model-zoo clones and downloaded weights use Foolbox's own cache (typically under ~/.foolbox_zoo), not these relative paths; inspect the exact returned path and never delete the whole cache as cleanup.

Cloning a zoo repository or downloading/extracting weights is a networked, potentially untrusted external-state operation. Obtain explicit approval before calling zoo.get_model(...) or zoo.fetch_weights(...), even when a cache entry may already exist. The local zoo checker and bundled sample assets are the offline alternatives.

Install and verify

Install the package and the small helper dependencies only with the environment's package-install/network approval; otherwise use an existing environment:

cd "$SKILL_ROOT"
python -m pip install foolbox pillow matplotlib
python -c "import foolbox as fb; print(fb.__version__)"

PyTorch, TensorFlow, and JAX are deliberately not base dependencies. Install one separately using its own supported wheel/build when the selected model or gradient attack needs it. Run the bundled CPU-native check before a larger workflow:

cd "$SKILL_ROOT"
python scripts/smoke.py --help
python scripts/smoke.py

Read references/api-reference.md for the verified public signatures and output-shape rules. Read references/troubleshooting.md when imports, bounds, preprocessing, optional frameworks, or attack outputs fail.

Route by task

• Wrap a model, prepare sample images, transform bounds, compute accuracy, or plot results: read sub-skills/models/SKILL.md.
• Choose or run attacks, compare robust accuracy, use criteria/distances, compose EOT or DatasetAttack, or author a new attack: read sub-skills/attacks/SKILL.md.
• Load a local/remote Foolbox model repository or fetch weights: read sub-skills/zoo/SKILL.md.

Core execution contract

1. Make the model callable through the matching Foolbox wrapper and state its input bounds before attacking. Include preprocessing and data format when they are not already native to the model.
2. Keep images and labels batched. Labels are a 1-D integer tensor aligned with the first dimension of model outputs.
3. Choose an untargeted label criterion (labels passed directly) or an explicit TargetedMisclassification(target_classes) criterion.
4. Call an attack with epsilons=<float>, epsilons=<sequence>, or None only when that attack supports minimization without a fixed budget.
5. Interpret (raw, clipped, success): clipped results obey the requested distance budget; success is a boolean mask of actual adversarial examples. For a sequence of epsilons, raw/clipped are lists and success has shape (K, N); for one scalar, outputs are tensors and success has shape (N,).
6. Report clean accuracy, attack family, distance, epsilon(s), backend, and robust accuracy (1 - success.float32().mean(axis=-1)) together.

Scope and limitations

The CPU/NumPy route and black-box/noise attacks are covered by the local smoke and native verification plan. Framework gradient attacks, EOT over stochastic models, and pretrained example models remain backend- and often network- dependent; do not claim them verified merely because import foolbox works. The model-zoo route can clone repositories or download weights and must be explicitly approved before network or external-state operations.

Provenance

Before using version-sensitive behavior or refreshing this skill, read references/repo-provenance.md.