After Hours

Defibrillators keep office hours. Cardiac arrest doesn't.

After Hours maps New York City's 4,032 public defibrillator (AED) locations by the hour, showing which ones sit behind an unlocked door. It replays 25,448 cardiac-arrest 911 calls from 2025 against those timetables, and ranks where a 24/7 street-wall cabinet would reach the most of them.

• Live site: https://dqcf6x4e7zbds.cloudfront.net

• Map: https://dqcf6x4e7zbds.cloudfront.net/map.html

• Bring your own data: https://dqcf6x4e7zbds.cloudfront.net/data.html

• API and live console: https://dqcf6x4e7zbds.cloudfront.net/api.html

• MCP server for AI assistants: claude mcp add --transport http after-hours https://dqcf6x4e7zbds.cloudfront.net/api/mcp

Built for the AWS Builder Center Weekend Challenge: Map it (October–November 2026).

What it found

Every number is computed by the pipeline in this repo and written to web/public/data/*/summary.json; the web pages fill them in at build time and never hardcode one.

Related MCP server: Magic Lane MCP Server

How it works

NYC Open Data ──► hours ──────────────► walking areas ──► coverage grid ──► presets (S3) ──► CloudFront site
 AED Inventory    school calendar        Amazon Location    50 m × 336 hours    + CSV downloads   API Gateway + Lambda
 FDNY dispatch    Amazon Location Places  Routes isolines    call-weighted                        MCP server
 ZIP polygons     Amazon Bedrock (graded)  (Pedestrian, 2 min)
Géo'DAE (France)
Overture Maps ◄── Amazon Athena (Registry of Open Data on AWS): fire/police/hospital hosts near top schools
EventBridge Scheduler ─► Lambda ─► S3 ─► Apache Iceberg table (Athena INSERT) ─► nightly "what changed" diff

Reuse the pattern

For your own list of places with hours (AEDs, naloxone boxes, cooling centres): upload a CSV or GeoJSON at /data.html, or

curl -X POST https://dqcf6x4e7zbds.cloudfront.net/api/v1/analyze \
  -H "x-api-key: YOUR_KEY" -H "content-type: application/json" \
  -d '{"timeZone":"America/Chicago","sites":[{"name":"Library","lat":41.876,"lon":-87.628,"hours":"Mo-Th 09:00-20:00"}]}'

Hours use OpenStreetMap opening_hours syntax. Unreadable hours are treated as unknown, never as open.

To run the whole thing:

npm install
npm test                         # engine tests
npm run fetch -w pipeline        # NYC Open Data
npm run paris -w pipeline        # Géo'DAE
npm run hours -w pipeline
npm run places -w pipeline       # Amazon Location Places (paid, cached)
npm run isolines -w pipeline     # Amazon Location Routes (paid, cached)
npm run infer -w pipeline        # Amazon Bedrock estimates + blind grade
npx tsx pipeline/src/overture.ts # Athena over Overture (needs the deployed workgroup)
npm run build -w pipeline        # presets, CSVs
npx tsx pipeline/src/build-samples.ts
npm run deploy -w infra          # CDK
sh scripts/deploy-web.sh         # build with the map key, sync to S3, invalidate

Limits

• FDNY publishes calls by ZIP code only, so each ZIP's calls are spread evenly over its streets.

• School hours are an assumption (7 AM–6 PM, school days); the map lets you try 3 PM and 9 PM.

• 1,278 venues have AI-estimated hours and 87 have none; both are excluded from headline numbers.

• An open building is not always an open AED. Real access is lower than shown.

• A planning tool, never an emergency service. In an emergency, call 911.

Data and credits

NYC AED Inventory, FDNY EMS Incident Dispatch Data and MODZCTA from NYC Open Data; Géo'DAE (Licence Ouverte 2.0); Overture Maps (ODbL/CDLA, via the Registry of Open Data on AWS); Paris arrondissements (ODbL). Photographs from Wikimedia Commons, credited in web/public/photos/credits.json. Research cited on /method.html.

Code: Apache-2.0. The opening_hours library is LGPL-3.0.