v2.2.0 — MCP Phase 2 & Repo-Wide Correctness Sweep

A repo-wide correctness sweep on top of the MCP Phase 2 rollout - three rounds of finding real gaps through direct verification (never guessed), fixing them, and closing out the "read-only lookups against paper/results-frozen/ and explainers/" plan named as a follow-up when the MCP server first shipped.

Highlights

• MCP Phase 2: list_explainers, get_explainer, and get_benchmark_results - read-only lookups an agent can call directly instead of shelling out, backed by real package-data mirrors (faircode/_explainers/, faircode/_results_frozen/) so a clean pip install faircode[mcp] actually has the files on disk
• 8 new explainers: Reject Option Classification, Simpson's Paradox, Differential Privacy, Subgroup Fairness, Conditional Demographic Parity, The Fairness-Accuracy Trade-off, Treatment Equality, and Multiple-Comparisons Correction
• @propcgamer20-png promoted to core code owner for /Makefile and /scripts/, following the largest sustained external contribution history in the project
• A wide correctness sweep, largely community-driven: a __proto__-named category silently vanishing from the web profiler's group counts (prototype pollution in a plain-object hashmap), several negative-zero rendering bugs (-0.0 pp/-0.00 instead of 0.0) across both the Python report renderer and its independent JS copy, a threshold-input bug that could permanently hide the profiler's results panel, CODEOWNERS coverage gaps (notebooks/, results/, assets/icons/, several .github/ files), stale documentation caught by re-running the actual code behind it (COMPAS's reduction percentage and dataset size, Benefits Denial's record count, a lifted paper-freeze policy still described as active in 7 audit READMEs), and a pr-review-ping.yml workflow that silently never pinged reviewers for 6 of the repo's 7 audit directories
• 15+ new backlog issues filed for contributors, each independently verified with a real repro before being opened

See CHANGELOG.md for the complete, credited list - this cycle touched dozens of files across faircode/, the web profiler, explainers, and CI/CODEOWNERS, each entry with its own verification.

Contributors this cycle

@propcgamer20-png, @slsgzs-cloud, @wangzhengzhuo05, @carryok, @raonishanth2000-hub, and @kevin-lozada-santos.

Install

pip install git+https://github.com/yakew7/Fair-Code.git@v2.2.0
pip install "faircode[mcp] @ git+https://github.com/yakew7/Fair-Code.git@v2.2.0"

PyPI (pip install faircode) is still on 2.0.0 - it hasn't been republished for this release yet.

Full changelog: CHANGELOG.md