dev-stats

A Claude Code skill that reports personal dev productivity: active hours from your local Claude Code and Codex CLI session transcripts, lines of code contributed across your repos via git log, and token usage with an estimated cost. Runs entirely locally — nothing is uploaded anywhere, pricing lookup is the only network call and it's optional (--no-tokens skips it).

What it measures

• Active hours — from ~/.claude/projects/**/*.jsonl and ~/.codex/sessions/**/*.jsonl. Approximate, double-counts parallel sessions by design. Extensible to other coding agents — see references/sources.md.
• Lines of code — git log --all --numstat per repo, scoped to your git identity. Walks every local branch, not just the checked-out one.
• Tokens + estimated cost — from the same session logs (Claude Code's per-message usage, Codex CLI's cumulative token_count event), priced against LiteLLM's public pricing data (the same source ccusage uses). Always an estimate at pay-as-you-go API rates — not your bill if you're on a subscription plan.

Neither source is authoritative on its own — this is a personal trend estimate, not a payroll ledger. Full detail on what each number can and can't tell you: references/methodology.md.

Install

/plugin marketplace add legacynik/dev-stats-skill
/plugin install dev-stats

Or locally, for testing: claude --plugin-dir /path/to/dev-stats-skill

Use

Inside Claude Code, just ask for a dev-stats/productivity report — the skill triggers on its own. Or run the scripts directly:

python3 scripts/dev_stats.py                          # cwd's siblings, all-time
python3 scripts/dev_stats.py --vault-dir ~/code --days 30
python3 scripts/backup_sessions.py --yes               # archive session logs before they age out

Full flag reference (period filters, repo/glob excludes, author aliases): references/flags.md.

Requirements

• Python 3, stdlib only — no pip install needed.
• git on PATH.
• Works with zero local session transcripts too (falls back to LOC-only).

Privacy and the archive step

backup_sessions.py copies raw session transcripts to ~/.dev-stats-archive/ and refuses to write inside a git repo. Details, and how to add your own encrypted container on top of disk encryption: references/privacy.md.

Repo layout

SKILL.md              — what Claude reads when this skill triggers
references/            — loaded on demand, not upfront
  sources.md           — session-log formats + how to add a new agent
  methodology.md        — what each number means, common misreadings
  flags.md              — full CLI reference
  privacy.md             — archive step, encryption
scripts/               — the actual implementation (stdlib only — pricing.py
                          makes one HTTP call via urllib, no pip installs)
evals/evals.json       — example prompts this skill should handle

Credits

Built by Niccolò Franzin with Claude Code — paired on the design, every fix in references/methodology.md traces back to something caught and verified live during that session (not just assumed to work).