Composable, verifiable location proof plugins for verifiable applications.

The Location Proof Framework is building an open ecosystem of location verification plugins that work with the Astral Protocol. Each plugin collects location evidence from a different proof-of-location system, from device-based GPS signatures to infrastructure network measurements.

Multifactor location verification - Combine multiple proof types to increase confidence:

• Device-based - ProofMode (PGP-signed GPS + hardware attestation)
• Infrastructure-based - WitnessChain (network latency triangulation)
• Future - Satellite signals, WiFi positioning, zkSNARKs, and more

npm install @decentralized-geo/astral-sdk @location-proofs/plugin-proofmode

import { AstralSDK } from '@decentralized-geo/astral-sdk';
import { ProofModePlugin } from '@location-proofs/plugin-proofmode';

const astral = new AstralSDK({ chainId: 84532, signer: wallet });

// Register plugins
astral.plugins.register(new ProofModePlugin());

// Create multifactor proof
const claim = {
  location: { type: 'Point', coordinates: [-73.9857, 40.7484] },
  radius: 100,
  time: { start: Date.now() / 1000, end: Date.now() / 1000 + 3600 }
};

const stamps = [
  await astral.stamps.create('proofmode', proofModeSignals),
  // Add more proof types for higher confidence
];

const proof = astral.proofs.create(claim, stamps);
const credibility = await astral.proofs.verify(proof);

console.log(credibility.score); // Multidimensional credibility vector

┌─────────────────────────────────────────┐
│     @decentralized-geo/astral-sdk       │  Core framework
│  (Plugin interface, proof verification) │
└─────────────────────────────────────────┘
                    ▲
                    │ implements
                    │
    ┌───────────────┴───────────────┬─────────────────┐
    │                               │                 │
┌───────────────┐        ┌──────────────────┐   ┌─────────┐
│  ProofMode    │        │  WitnessChain    │   │ Custom  │
│   Plugin      │        │     Plugin       │   │ Plugins │
└───────────────┘        └──────────────────┘   └─────────┘
  Device-based           Infrastructure-based    Community

Plugins are responsible for:

• ✅ Signal collection (GPS, network data, etc.)
• ✅ Stamp creation (wrapping raw signals in standard format)
• ✅ Internal verification (signatures, structure, signal consistency)

SDK is responsible for:

• ✅ Spatial/temporal evaluation (haversine distance, overlap)
• ✅ Multidimensional credibility scoring
• ✅ Cross-stamp correlation analysis
• ✅ On-chain attestation (via EAS)

Multifactor approach: Combine multiple compatible plugins to get high-precision device proof + independent infrastructure validation. (We're currently researching whether ProofMode and WitnessChain can be used to verify the location of the same device.)

Want to add a new proof-of-location system? See the Plugin Development Guide.

Plugin interface:

interface LocationProofPlugin {
  readonly name: string;
  readonly version: string;
  readonly runtimes: Runtime[];

  // Optional: Collect raw signals
  collect?(options?: CollectOptions): Promise<RawSignals>;

  // Required: Transform signals into stamps
  create(signals: RawSignals): Promise<UnsignedLocationStamp>;

  // Optional: Sign stamps
  sign?(stamp: UnsignedLocationStamp, signer: StampSigner): Promise<LocationStamp>;

  // Required: Verify stamp validity
  verify(stamp: LocationStamp): Promise<StampVerificationResult>;
}

Explore the academic foundations of proof-of-location systems:

• Towards Harder Location Proofs - Flashbots Collective discussion
• OSF Preprint - Open Science Framework research paper
• Research Repository - Survey of PoL systems, threat models, and verification methods

• Documentation
• Astral SDK
• Telegram (coming soon)
• Twitter

Location Proofs is part of the broader Astral ecosystem:

• Astral Protocol - Verifiable location-based services
• DecentralizedGeo - Decentralized geospatial infrastructure
• Astral SDK - Core SDK for location proofs

All plugins are MIT licensed. See individual repositories for details.

Built with ✨ by the Astral community