repo-activity-summary

name	repo-activity-summary
description	Summarize a repository's recent engineering activity from git history — technologies, work types, churn hotspots, contributor patterns, and velocity. Use when asking "what has this repo been working on", "is this project active", "who contributes what", "where are the hotspots", or before onboarding onto an unfamiliar codebase.
license	MIT
compatibility	Any coding agent with shell access. Requires git and Python 3.9+. No API keys or network access needed.
allowed-tools	Bash(git:*), Bash(python3:*), Read
metadata	{"version":"1.1.0","methodology":"commit-signal-extraction"}

Repo Activity Summary

Answer "what's been happening in this repo" from local git history — no network, no tokens, no setup.

Trigger conditions

Use this skill when the user asks:

• "What has this repo been working on recently?"
• "What technologies does this project use?"
• "Where are the high-churn files / hotspots?"
• "Who's contributing and what are they working on?"
• "Is this project actively maintained?"
• Before onboarding onto an unfamiliar codebase.

Do not use this skill for file-level blame or provenance — use investigating-repository-history for that.

Quick start

python3 scripts/activity_summary.py --repo-dir . --days 90

Flag	Default	Description
--repo-dir	.	Path to the git repository
--days	90	Days of history to analyze
--author	(all)	Filter to one author
--format	markdown	markdown, json, or text
--max-commits	500	Cap for very active repos
--branch	(current)	Branch / revision to analyze (must not start with -)
--output / -o	(stdout)	Write the report to a file (UTF-8)
--classify-threshold	0.25	If the share of unclassified commits exceeds this fraction, mark work-type classification unreliable and emit subject samples
--max-unclassified-samples	40	Cap on unclassified commit subjects included in the report
--raw-subjects	off	Emit every filtered commit subject with sha and date for agent-side classification
--version	—	Print version (1.1.0) and exit

What it produces

A structured report with:

1. Overview — commit count, date range, contributors, lines added/deleted
2. Technologies — languages and frameworks inferred from file paths (heuristic)
3. Work type breakdown — feature / bugfix / refactor / docs / infra / release / … (keyword heuristic)
4. Unclassified subjects — when keyword classification is unreliable, the raw subjects so the agent can classify them
5. Churn hotspots — most frequently modified files and directories (lockfiles/generated paths excluded)
6. Contributor patterns — per-author commits, lines, and primary focus
7. Velocity — commits/week, active days, average commit size (same noise filter as churn)
8. Project health — test modules (by basename/path convention), CI, docs, recency

How it works

1. Collects commits via git log --numstat --no-renames with an explicit UTC --since timestamp
2. Filters bots (GitHub-style [bot] names and known automation identities) and keeps the filtered count
3. Detects technologies from extensions, exact manifest filenames, and path segments — never bare path substrings; requires a manifest hit or at least two source files
4. Classifies work types with precompiled word-boundary regexes and scored multi-label tie-break; does not present a large "Other" bucket as a finding
5. Ranks files/directories by modification frequency
6. Aggregates per-author stats using the same classifier
7. Checks for test modules, CI config, documentation, and last activity date

Agent guidance

• Prefer the facts in the report (counts, paths, subjects, dates) over the keyword labels.
• When classification.unreliable is true, or the unclassified share is high, classify from the emitted subjects (or re-run with --raw-subjects) instead of trusting the work-type percentages.
• Technology labels are path heuristics, not an import graph — verify against manifests when it matters.

Limitations

• Shallow clones (--depth 1) limit the analysis window.
• Technology detection is a heuristic (extensions, manifests, path segments — not imports or lockfile graphs). Labels are hints.
• Work-type classification is a keyword heuristic, not ground truth. Conventional-commit prefixes classify well; free-form subjects often do not. When the unclassified share exceeds --classify-threshold (default 25%), the report says so and emits subjects for the agent to classify.
• Average commit size and churn exclude lockfiles and common generated/vendor paths; the report states this filter.
• Summarizes activity, not code quality.