[berkgeveci]

An experiment. Not to merge before the 0.7 release.

A changes job sorts the pull request's changed files into groups (tools/ci_changes.py, first match wins). Each job then runs only if its group is needed; the others report "skipping". Pushes to main and runs started by hand run everything.

What the PR changes	Jobs that run
docs/, mkdocs.yml, overrides/, Markdown outside the packages	lint, docs
packages/*/examples/	lint, examples
tools/, changelog.d/, archive/, LICENSE	lint only
package code or tests, pyproject.toml, uv.lock, conftest.py, test-durations.json, .github/, benchmarks/	everything, Metal included
anything not listed	everything

• Docs-only changes still run the package tests that read the docs pages. Those are test_reference_pages.py and test_every_algorithm_has_a_wrapper, and the docs job now runs them too.
• benchmarks/ counts as code because test_threading_benchmark.py runs a script from it.
• How the changed files are found: the job checks out the PR's merge commit at depth 2 and diffs it against its first parent, the base. No third-party action is involved.
• Documented in CONTRIBUTING.md and CLAUDE.md.
• This PR's own run will run everything, because it changes ci.yml. Seeing the filter skip anything needs a docs-only PR stacked on this one.

Checked locally: actionlint, ruff, the tools tests (including the new test_ci_changes.py) and the docs-reading tests.

🤖 Generated with Claude Code