SafeRelay

Offline-first emergency relay and evidence-scoped disaster operations, built with Jac.

SafeRelay helps people move a distress packet across nearby phones when normal connectivity is unavailable, then gives operators a source-backed view of public hazards and received evidence when connectivity returns.

This is the canonical SafeRelay repository and contains both product surfaces:

• mobile/ is the field relay for composing, validating, storing, and forwarding emergency packets.
• web/ is the public operations console for public hazard monitoring and evidence review.

Both applications are independent Jac projects. Native iOS code is limited to the platform bridges and entitlements that Capacitor cannot express directly.

How It Works

flowchart LR
    PERSON["Person in distress"] --> PHONE_A["SafeRelay field app"]
    PHONE_A -->|"Always-on Bluetooth relay"| PHONE_B["Nearby SafeRelay device"]
    PHONE_B -->|"Store and forward, hop 1"| PHONE_C["Farther SafeRelay device"]
    PHONE_A -->|"Automatic upload when reachable"| CLOUD["Jac cloud relay"]
    PHONE_B -->|"Store, forward, and upload when reachable"| CLOUD
    CLOUD --> CONSOLE["SafeRelay operations console"]
    USGS["USGS earthquakes"] --> CONSOLE
    NWS["NWS severe weather"] --> CONSOLE

Loading

The mobile app treats each relay hop, cloud upload, responder acknowledgement, and outcome as a separate piece of evidence. The web console never generates operational records to fill an empty state. Synthetic markers appear only in clearly labeled map layers and are excluded from evidence counts.

Built With Jac

• Jac 0.34.7 for application logic, graph state, protocol policy, tests, and UI
• Typed public Jac functions for anonymous web RPC
• Typed public Jac ingestion for idempotent mobile cloud receipts
• Shared public Jac graph state for the console and mobile relay
• Capacitor 8 for the native mobile shell
• CoreBluetooth for the iOS central and peripheral bridge
• Apple Foundation Models for the optional on-device Survival Guide
• Mapbox GL, USGS, NWS, NOAA, and GDACS for maps and public hazard context

Run The Web Console

cd web
export PROMETHEUS_ADMIN_PASSWORD="$(openssl rand -base64 32)"
export MAPBOX_ACCESS_TOKEN="<public Mapbox token>"
jac install
jac start --dev main.jac

Open http://localhost:8000.

Verify the web project:

cd web
jac check .
jac test
jac build main.jac

Run The Mobile App

cd mobile
jac install
bun install
cp -n .env.example .env
# Set SAFERELAY_CLOUD_URL in .env to the public JacHammer deployment origin.
jac check .
jac test tests/protocol_tests.jac tests/operations_tests.jac -v
jac build --client mobile --platform ios

The native radio path must be validated on two physical, Apple Intelligence-capable iPhones. A browser preview, simulator, successful build, or passing protocol tests does not prove Bluetooth scanning, advertising, background continuity, or phone-to-phone delivery. End-to-end multi-hop claims additionally require three physical iPhones with the two endpoint phones independently confirmed outside direct radio range.

Repository Layout

Path	Responsibility
mobile/	Offline-first field relay, protocol, services, tests, and native shell
web/	Public landing experience and operations console
design/	App icon source layers and export tooling
.github/workflows/	Validation and web deployment automation

Start with the mobile documentation or web documentation. Production constraints and release gates for the hosted console are documented in web/PRODUCTION.md.

Evidence Boundary

SafeRelay is not an emergency dispatch service. It does not infer that a packet was delivered, seen by a responder, or resolved. Those states remain unknown until their own evidence exists. Public-feed failure retains verified cached records or reports the source as unavailable; it never creates fallback incidents.

Team

Created by Jerry Wen, Rishabh Bansal, and Aditya Das for JacHacks 2026.

License

Copyright (c) 2025 SafeRelay Team. All Rights Reserved.

This is proprietary software. No copying, modification, distribution, or resubmission to hackathons is permitted without explicit written permission. See web/LICENSE for the full terms.