Reference

Reference material that does not fit into a narrative section.

Pages

• Configuration — every config file in the repo and what it controls.
• Dependencies — required runtime deps and the structure of optional extras.

At-a-glance: top-level files

File	Purpose
setup.py	Package metadata, deps, extras
pyproject.toml	ruff, ty, pytest configuration
Makefile	Dev commands
conftest.py	Pytest fixtures and import hooks
MIGRATION_GUIDE_V5.md	V5 migration guide
CONTRIBUTING.md	Contribution etiquette
AGENTS.md (= .ai/AGENTS.md), CLAUDE.md (alias)	AI-agent contribution policy
ISSUES.md	Issue triage policy
CODE_OF_CONDUCT.md	Community code of conduct
SECURITY.md	Security disclosure
awesome-transformers.md	Curated list of community projects
LICENSE	Apache 2.0
CITATION.cff	Citation metadata

Top-level directories

Directory	Contents
src/transformers/	Library code
tests/	Test suite
examples/pytorch/	Reference fine-tuning scripts
benchmark/, benchmark_v2/	Benchmarking harnesses
docker/	CI Dockerfiles
docs/source/en/, docs/source/<other>/	User documentation
i18n/	Translated READMEs
notebooks/	Notebooks (mostly maintained externally)
scripts/	Misc scripts
utils/	Repo-consistency helpers and CI plumbing
.github/, .circleci/	CI configuration
.ai/skills/	In-tree agent skill assets (used by make codex / make claude)