Open source · MIT · Node.js 18+

An embeddable rules engine for location streams

Drop it into your Node.js process. Feed it position updates. Receive typed spatial events — enter, exit, approach, recede — synchronously, with no server, no network calls, and no external dependencies.

Get started →GitHub

geo-stream · quickstart.ts

1import { GeoEngine } from '@jamesholcombe/geo-stream'
2
3const engine = new GeoEngine()
4  .registerZone('warehouse', warehousePolygon)
5  .registerCircle('depot', 500, 300, 50)  // cx, cy, radius (metres)
6  .defineRule('fast-entry', rule =>
7    rule.whenEnters('warehouse').speedAbove(15).emit('speeding-alert')
8  )
9
10// Feed in position updates — events come back synchronously
11const events = engine.ingest([
12  { id: 'driver-1', x: 505, y: 298, tMs: Date.now() },
13])
14// [{ kind: 'approach', id: 'driver-1', circle: 'depot', t_ms: ... }]

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In-process, zero latency

A native Rust module. No server, no network hop, no round-trip per update. State lives in your process.

🔁

Deterministic

Same inputs always produce the same events in the same order. Replay, backtest, and unit test with exact reproducibility.

⏱️

Dwell and sequences

Debounce noisy boundary crossings with per-zone dwell thresholds. Detect ordered multi-stop routes with sequence rules.

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Adapters included

EventEmitter, Kafka, and Redis Streams adapters ship in the box. Structural typing — no hard deps.

Get started in seconds

npm install @jamesholcombe/geo-stream

Pre-built native binaries for macOS, Linux, and Windows. No Rust toolchain required.

Read the docs →