# OpenSpec Change: enterprise-network-observability

- **Change ID**: enterprise-network-observability
- **Package**: `@suaveplan/network-observability`
- **Category**: universal/network
- **Target path**: `universal/network/network-observability`
- **Status**: SUPERSEDED-BY-GENESIS-WAVE
- **Date**: 2026-04-24

---

## Summary

Deliver `@suaveplan/network-observability` on the genesis branch from scratch at enterprise quality. The package provides network metrics collection and distributed tracing instrumentation: RTT measurements, bandwidth estimation, connection health scoring, packet loss tracking, span propagation across network hops, and structured event emission for network anomalies. Genesis adds structured errors via `@suaveplan/error`, Zod schemas for all metric types, deep OTel integration (this package is specifically about observability), `AbortSignal` on collection tasks, injectable `Clock` for measurement timestamps, and event-bus emission for threshold breaches.

---

## 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 `NetworkObservabilityError`; stable error codes |
| `@suaveplan/types` (`workspace:^`) | `LoggerLike`, `Clock`, `EventBusLike` |
| `@suaveplan/events` (`workspace:^`) | Event bus for threshold breach notifications |
| `@suaveplan/logger` (`workspace:^`) | Structured logging |
| `@suaveplan/timing` (`workspace:^`) | Stopwatch and throttle for measurement intervals |
| `zod` (`catalog:forms`) | Zod schemas for all public metric types |
| `@opentelemetry/api` (`catalog:observability`) | Deep OTel integration — this package enriches OTel spans |
| `tslib` (`catalog:build`) | Runtime helpers |

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

---

## Public API surface

### Core

```ts
function createNetworkMonitor(options?: NetworkMonitorOptions): NetworkMonitor

interface NetworkMonitor {
  start(signal?: AbortSignal): Promise<void>
  stop(): void
  snapshot(): NetworkSnapshot
  history(limit?: number): ReadonlyArray<NetworkSnapshot>
  on(event: NetworkEvent, handler: (data: NetworkSnapshot) => void): () => void
}
```

### Metric types

```ts
interface NetworkSnapshot {
  readonly timestamp: number
  readonly rtt: RttMetrics
  readonly bandwidth: BandwidthMetrics
  readonly packetLoss: PacketLossMetrics
  readonly health: NetworkHealthScore
}

interface RttMetrics {
  readonly current: number
  readonly min: number
  readonly max: number
  readonly avg: number
  readonly p50: number
  readonly p95: number
  readonly p99: number
  readonly samples: number
}

interface BandwidthMetrics {
  readonly downloadBps: number
  readonly uploadBps?: number
  readonly estimatedAt: number
}

interface PacketLossMetrics {
  readonly rate: number  // 0–1
  readonly total: number
  readonly lost: number
}

interface NetworkHealthScore {
  readonly score: number  // 0–100
  readonly grade: 'excellent' | 'good' | 'fair' | 'poor' | 'critical'
  readonly factors: ReadonlyArray<HealthFactor>
}

interface HealthFactor {
  readonly name: string
  readonly weight: number
  readonly score: number
  readonly impact: 'positive' | 'negative' | 'neutral'
}
```

### Span propagation

```ts
function injectTraceContext(headers: Record<string, string>): Record<string, string>
function extractTraceContext(headers: Record<string, string>): SpanContext | null
function withNetworkSpan<T>(name: string, fn: () => Promise<T>, attributes?: NetworkSpanAttributes): Promise<T>

interface NetworkSpanAttributes {
  url?: string
  method?: string
  statusCode?: number
  requestSize?: number
  responseSize?: number
}
```

### Options

```ts
interface NetworkMonitorOptions {
  measureIntervalMs?: number
  historySize?: number
  rttTargetUrl?: string
  thresholds?: NetworkThresholds
  logger?: LoggerLike
  clock?: Clock
  eventBus?: EventBusLike
}

interface NetworkThresholds {
  maxRttMs?: number
  minBandwidthBps?: number
  maxPacketLossRate?: number
  minHealthScore?: number
}

type NetworkEvent = 'snapshot' | 'threshold-breach' | 'recovery'
```

### Error codes

```ts
type NetworkObservabilityErrorCode =
  | 'NET_OBS_MEASUREMENT_FAILED'
  | 'NET_OBS_MONITOR_ALREADY_RUNNING'
  | 'NET_OBS_ABORT'

function registerNetworkObservabilityErrorCodes(): void
```

---

## Genesis additions

1. **Structured `NetworkObservabilityError`** with stable `NET_OBS.*` codes
2. **Zod schemas** for all metric types and options
3. **Health scoring algorithm** — weighted composite of RTT, packet loss, bandwidth; grades A–F
4. **W3C Trace Context propagation** helpers (`injectTraceContext`, `extractTraceContext`)
5. **Threshold alerting** — emits event-bus events when thresholds are breached or recovered
6. **Injectable `Clock`** for deterministic timestamp tests
7. **OTel deep integration** — this package is the entry point for network-layer OTel spans

---

## File layout

```text
universal/network/network-observability/
  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
      health/
        health.ts
        health.md
        health.test.ts
        index.ts
    tracing/
      propagation.ts
      propagation.md
      propagation.test.ts
      index.ts
    metrics/
      rtt.ts
      rtt.md
      rtt.test.ts
      bandwidth.ts
      bandwidth.md
      bandwidth.test.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.