# OpenSpec Change: enterprise-network-quality

- **Change ID**: enterprise-network-quality
- **Package**: `@suaveplan/network-quality`
- **Category**: universal/network
- **Target path**: `universal/network/network-quality`
- **Status**: SUPERSEDED-BY-GENESIS-WAVE
- **Date**: 2026-04-24
- **Reference spec**: `/mnt/s/web/suaveplan/enterprise/network-quality.md`

---

## Summary

Deliver `@suaveplan/network-quality` on the genesis branch from scratch at enterprise quality. The package provides network quality monitoring: continuous measurement of RTT, jitter, packet loss, and throughput; quality scoring with configurable thresholds; trend analysis (sliding window, exponential smoothing); degradation alerts; and a quality-aware selector for choosing the best peer/transport. Genesis adds structured errors via `@suaveplan/error`, Zod schemas for measurement and threshold types, OTel instrumentation on all quality metrics, `AbortSignal` on collection tasks, injectable `Clock` for measurement timestamps, event-bus emission for quality degradation and recovery, and property-based tests for scoring invariants.

---

## Current-state audit (genesis)

The package does not exist on genesis yet — this is a fresh build.

---

## Available workspace deps on genesis

| Package | Role |
|---|---|
| `@suaveplan/error` (`workspace:^`) | Base class for `NetworkQualityError`; stable error codes |
| `@suaveplan/types` (`workspace:^`) | `LoggerLike`, `Clock`, `EventBusLike` |
| `@suaveplan/events` (`workspace:^`) | Event bus for quality change events |
| `@suaveplan/logger` (`workspace:^`) | Structured logging |
| `@suaveplan/timing` (`workspace:^`) | Stopwatch and interval timer for measurement |
| `zod` (`catalog:forms`) | Zod schemas |
| `@opentelemetry/api` (`catalog:observability`) | Deep OTel metric emission for network quality |
| `tslib` (`catalog:build`) | Runtime helpers |

Dev deps: `vitest`, `@vitest/coverage-istanbul`, `fast-check` (all `catalog:testing`).

---

## Public API surface

### Core

```ts
function createQualityMonitor(options?: QualityMonitorOptions): QualityMonitor

interface QualityMonitor {
  readonly score: number
  readonly grade: QualityGrade
  start(signal?: AbortSignal): Promise<void>
  stop(): void
  measure(probe: QualityProbe): Promise<QualityMeasurement>
  report(): QualityReport
  on(event: QualityEvent, handler: (report: QualityReport) => void): () => void
}
```

### Measurement types

```ts
interface QualityMeasurement {
  readonly rttMs: number
  readonly jitterMs: number
  readonly packetLoss: number    // 0–1
  readonly throughputBps?: number
  readonly timestamp: number
}

interface QualityReport {
  readonly score: number          // 0–100
  readonly grade: QualityGrade
  readonly current: QualityMeasurement
  readonly trend: QualityTrend
  readonly window: QualityWindowStats
  readonly thresholdViolations: ReadonlyArray<ThresholdViolation>
}

interface QualityWindowStats {
  readonly avgRttMs: number
  readonly avgJitterMs: number
  readonly avgPacketLoss: number
  readonly p95RttMs: number
  readonly sampleCount: number
  readonly windowMs: number
}

type QualityTrend = 'improving' | 'stable' | 'degrading'
type QualityGrade = 'excellent' | 'good' | 'fair' | 'poor' | 'critical'

interface ThresholdViolation {
  readonly metric: string
  readonly threshold: number
  readonly actual: number
  readonly severity: 'warning' | 'critical'
}
```

### Probe and selector

```ts
type QualityProbe = (signal?: AbortSignal) => Promise<QualityMeasurement>

function createRttProbe(url: string, options?: RttProbeOptions): QualityProbe
function createBandwidthProbe(url: string, options?: BandwidthProbeOptions): QualityProbe

function selectBestPeer<T extends { id: string; score?: number }>(
  peers: T[],
  monitor: QualityMonitor
): T | null
```

### Options

```ts
interface QualityMonitorOptions {
  measureIntervalMs?: number
  windowSize?: number            // number of samples in sliding window
  smoothingFactor?: number       // 0–1 for exponential smoothing
  thresholds?: QualityThresholds
  probe?: QualityProbe
  logger?: LoggerLike
  clock?: Clock
  eventBus?: EventBusLike
}

interface QualityThresholds {
  maxRttMs?: number
  maxJitterMs?: number
  maxPacketLoss?: number
  minThroughputBps?: number
  degradationScore?: number
  criticalScore?: number
}

type QualityEvent = 'measurement' | 'degradation' | 'recovery' | 'critical'
```

### Error codes

```ts
type NetworkQualityErrorCode =
  | 'QUALITY_PROBE_FAILED'
  | 'QUALITY_MONITOR_RUNNING'
  | 'QUALITY_NO_MEASUREMENTS'
  | 'QUALITY_ABORT'

function registerNetworkQualityErrorCodes(): void
```

---

## Genesis additions

1. **Structured `NetworkQualityError`** with stable `QUALITY.*` codes
2. **Zod schemas** for `QualityMonitorOptions`, `QualityThresholds`
3. **Exponential smoothing + sliding window** statistics
4. **Trend detection** — compares recent half of window against older half
5. **Quality scoring** — weighted composite (RTT 40%, jitter 20%, packet loss 30%, throughput 10%)
6. **`createRttProbe` / `createBandwidthProbe`** factory utilities
7. **OTel metric emission** — gauges for `net.quality.rtt`, `net.quality.jitter`, `net.quality.packet_loss`, `net.quality.score`
8. **Property-based tests** — score monotonically decreases as RTT increases; grade ordering matches score ordering

---

## File layout

```text
universal/network/network-quality/
  package.json
  tsconfig.json
  vitest.config.ts
  src/
    index.ts
    error-codes.ts
    constants/
      index.ts
    types/
      common.ts
      common.md
    core/
      monitor/
        monitor.ts
        monitor.md
        monitor.types.ts
        monitor.test.ts
        index.ts
    scoring/
      scorer.ts
      scorer.md
      scorer.test.ts
      index.ts
    stats/
      window-stats.ts
      window-stats.md
      window-stats.test.ts
      index.ts
    probes/
      rtt-probe.ts
      rtt-probe.md
      rtt-probe.test.ts
      bandwidth-probe.ts
      bandwidth-probe.md
      bandwidth-probe.test.ts
      index.ts
    __benchmarks__/
      quality.bench.ts
  tests/
    integration.test.ts
    property.test.ts
```

---

## Impact

**Workspace dep prerequisites**: `@suaveplan/error`, `@suaveplan/types`, `@suaveplan/events`, `@suaveplan/logger`, `@suaveplan/timing` must be published.