SunSpot
SunSpot helps you find possible direct sunlight at parks, bars and
restaurants in Copenhagen, choose a time and invite friends.
Run locally
Use Node 24 (nvm use; .nvmrc is included), or Node 22.13+ /
24.x / 26+ per package.json's engines:
npm ci
npm run dev
Open localhost:3000. No API keys are required.
Invitations and the MET Norway weather cache are stored in .data/,
excluded from Git.
What's included
- Full-screen map, compact mobile controls and a continuous seven-day time
slider. Nearby places form tappable groups at city scale; search and the
list retain the full selection.
- Touchgrass, bar, restaurant and event filters; partial shade does not
exclude an entire park.
- 163 places, 139 OSM park areas and a building-shadow model with 19,523
buildings. Solar analysis and shadow rasterization run in separate Web
Workers and follow the selected time. Older browsers use a throttled
canvas fallback.
- Real events from Københavns Biblioteker, plus one manually-verified
curated listing, with a weekly discovery list and rich event details.
Markers follow event start/end times; fictional demo events are optional
and off by default.
- MET Norway forecasts for the selected time, invitations, guest RSVPs and
host cancellation.
- Editable seating points and in-app solar warnings. System notifications
require user activation and a running app; this is not background push.
Verification
npm test # node's built-in test runner (tests/*.test.js)
npm run lint
npm run build
npm run test:browser # requires a running app on port 3000
npm run test:solar
npm run test:events # event feed, mobile details and timeline behaviour
npm run test:map # grouping, mobile layout, worker/fallback and responsiveness
For browser tests, install Chromium with npx playwright install chromium,
or set SUNSPOT_BROWSER_PATH to an existing Chrome executable. Override
the app URL with SUNSPOT_URL=http://localhost:4174. Tests create and
cancel their own local invitations.
Runtime and deployment
Use npm run build && npm start on a Node server with writable
persistent storage for invitations. SUNSPOT_DATA_DIR can select an
absolute path on that disk. Set SUNSPOT_PUBLIC_ORIGIN to the public
origin when running behind a reverse proxy so mutation-origin checks use
the correct host and scheme. The local SQLite pilot targets one server and
has a shared API request budget of 100 requests/minute per process.
Invitations are not ready for Vercel deployment. The Vercel runtime
explicitly returns a 503 response for invitation APIs rather than storing
them in a temporary filesystem (no persistent disk there). Map, solar
analysis, events and forecasts all work fine on Vercel — a shared database
is the next deployment work needed before invitations work there too.
Deployed at sunspot-sigma.vercel.app.
Accuracy and sources
Building heights are often estimated, and trees, terrain and detailed roof
shapes are absent. Sunny means possible direct building-unobstructed
sunlight, not a cloud-free weather guarantee. Outside the building extract,
or at very low sun angles, the model reports unknown. OSM hours and seating
areas are approximate snapshots, not verified business availability.
History
This app began as a narrower Next.js/TypeScript prototype (shadows +
weather + sun-exposed benches/parks, see
docs/superpowers/) before merging in a substantially
more capable rewrite: the build-time OSM data pipeline (replacing live
Overpass calls, which were rate-limit prone), more accurate prism-based
shadow geometry, off-main-thread rendering, and the event/invite feature.
Two regressions from the original prototype (a suncalc units bug, and a
"sun below horizon" false-positive) were fixed before that merge and are
covered by tests/shadows.test.js and tests/parks.test.js.
Product and prototype documentation under docs/01–docs/17 (Swedish)
and docs/superpowers/ (English) record that history in more detail.
Code license: MIT. Geographic and weather data retain their own
attribution and license.
