Inkblot

Sign in with GitHub and watch your commit history bloom into a symmetric streamgraph. A Rorschach inkblot of every late night you shipped — a small, frictionless pat on the back for the grind.

The band thickness at any moment is your commits-per-hour; each repo is a colored ribbon, busiest one straddling the centerline. Toggle repos on and off and drag the time window — the chart re-blooms as you fiddle.

Quickstart

pnpm install
cp .env.example .env.local     # then fill in the three values (see below)
pnpm dlx vercel dev            # runs Next.js + the Python renderer together

Open http://localhost:3000, click Sign in with GitHub, and your chart renders itself.

Use vercel dev (not next dev) for local development: the chart is rendered by a Python serverless function, which only vercel dev serves locally. next dev runs everything except the chart endpoint.

The three env values

Variable	Where it comes from
AUTH_GITHUB_ID / AUTH_GITHUB_SECRET	A GitHub OAuth App — callback http://localhost:3000/api/auth/callback/github
AUTH_SECRET	openssl rand -base64 32

How it works

flowchart LR
  U[Sign in with GitHub] --> A["/api/activity (Node)"]
  A -->|Octokit Search Commits| G[(GitHub)]
  A -->|bin hourly + onset window| C[client cache]
  C -->|repos + time window| R["/api/render (Python · matplotlib)"]
  R -->|PNG| C

Loading

• Auth — Auth.js (NextAuth v5) with a single GitHub provider. The OAuth token lets the app read your authored commits (public always; private with the repo scope).
• Data (/api/activity, Node) — pulls your commits via the Search Commits API, bins them into per-repo hourly counts, and computes the default time window: it opens just before your activity ramps up. The heavy fetch happens once.
• Render (/api/render, Python) — a matplotlib port of the symmetric stacked streamgraph. The client re-POSTs the cached series with your current repo selection and window; debounced, with the in-flight render aborted when you keep fiddling, so it stays snappy.

Defaults that just work

• All repos selected.
• Time window auto-starts just before activity got intense (smoothed-onset detection), so the chart opens on the interesting part of your history.

Privacy

Inkblot reads commit metadata (repo name + timestamp) to draw the chart. It renders on the fly and does not store your code or your commits — there is no database. The GitHub token lives only in your encrypted session cookie.

Stack

Next.js 16 (App Router) · shadcn/ui + Tailwind v4 · Auth.js v5 · Octokit · matplotlib (Vercel Python function). Deploy with vercel --prod.

Tests

pnpm test                     # TypeScript: binning + onset detection + repo labels
python3 api/test_inkblot.py   # Python: renderer contract invariants