Core API

Every export from @wcgw/vibe-check-core — engine, collectors, detectors, beacon, config, and utilities.

@wcgw/vibe-check-core is framework-agnostic with zero runtime dependencies. Everything below is a named export (this package has no default export).

Engine

VibeCheckEngine — the main class. Constructor takes Partial<VibeCheckConfig>.
VibeEngine — the interface both the live and scripted engines implement.

class VibeCheckEngine implements VibeEngine {
  constructor(config?: Partial<VibeCheckConfig>)
  start(): void
  stop(): void
  isRunning(): boolean
  getSnapshot(): VibeSnapshot
  getIssues(): readonly VibeIssue[]
  clearIssues(): void
  onSnapshot(cb: (snapshot: VibeSnapshot) => void): () => void   // fires ~every 500ms
  getBeaconStatus(): BeaconStatus | null
}

Scripted engine

createScriptedEngine(scenario: ScriptedScenario): VibeEngine
types ScriptedScenario, ScriptedFrame

Replays a canned timeline instead of live collectors. See The Engine.

Configuration

VibeCheckConfig — the config type.
DEFAULT_CONFIG — the defaults the constructor merges over.

interface VibeCheckConfig {
  readonly enabled: boolean            // default true
  readonly beaconUrl?: string          // default undefined (local-only)
  readonly beaconIntervalMs: number    // default 2000
  readonly detectors: {                // one boolean per detector, all true
    domBloat, duplicateRequests, consoleSpam, memoryLeak, layoutThrashing,
    unoptimizedImages, longTaskAttribution, resourceBloat, largeImages,
    webEssentials, heavyLibrary, seo, aeo
  }
}

Collectors

Each implements Collector<T> (start / stop / getStats / onUpdate). See Collectors for what each measures.

FrameRateCollector, LongFrameCollector, MemoryCollector, WebVitalsCollector, ResourceCollector, ConsoleCollector.

Detectors

Each is a factory returning a Detector (start / stop / getIssues / clear). See the Detector reference for thresholds.

createDomBloatDetector, createDuplicateRequestsDetector, createConsoleSpamDetector, createMemoryLeakDetector, createLayoutThrashingDetector, createUnoptimizedImagesDetector, createLongTaskAttributionDetector, createResourceBloatDetector, createLargeImagesDetector, createWebEssentialsDetector, createHeavyLibraryDetector, createSeoDetector, createAeoDetector.

Also exported: SEO_CRITERIA_COUNT, AEO_CRITERIA_COUNT, LIBRARY_SIGNATURES, and the LibrarySignature type.

Beacon

BeaconClient — POSTs snapshots to <url>/api/snapshot on an interval.
types BeaconClientConfig, BeaconStatus

See The Beacon.

Suggestions

getSuggestion(issue: VibeIssue, mode?: SuggestionMode): Suggestion
getAgentPrompt(issues: readonly VibeIssue[], mode?: SuggestionMode): string
PROACTIVE_PROMPTS: readonly ProactivePrompt[]
types SuggestionMode ('technical' | 'vibe'), Suggestion, ProactivePrompt

Utilities

RingBuffer — fixed-capacity circular buffer used by the collectors.

Feature detection

Each returns a boolean; the engine uses them to skip unsupported collectors.

hasPerformanceObserver, hasEntryType(type), hasPerformanceMemory, hasLongAnimationFrame, hasLayoutShift, hasLargestContentfulPaint, hasEventTiming, hasMutationObserver, hasResourceTiming.

import { hasPerformanceMemory } from '@wcgw/vibe-check-core'

if (!hasPerformanceMemory()) {
  // Non-Chromium: memory metrics read null, memory-leak stays quiet.
}

Types

`VibeSnapshot`

The wire payload — what getSnapshot() returns and the beacon POSTs.

interface VibeSnapshot {
  readonly timestamp: number
  readonly frameRate: FrameRateStats
  readonly longFrames: LongFrameStats
  readonly webVitals: WebVitalsStats
  readonly memory: HeapMemory | null
  readonly resources: ResourceStats
  readonly console: ConsoleStats
  readonly issues: readonly VibeIssue[]
  readonly domNodeCount: number
}

Everything else

Also exported as types: VibeIssue, Severity, DetectorName, FrameRateStats, LongFrameStats, LongFrameEntry, ScriptAttribution, WebVitalsStats, WebVitalEntry, VitalRating, HeapMemory, ResourceStats, LargeResource, ConsoleStats, Collector, Detector, IssueEvidenceMap, EvidenceFor, plus the EMPTY_* stat constants (EMPTY_FRAME_RATE_STATS, EMPTY_LONG_FRAME_STATS, EMPTY_WEB_VITALS, EMPTY_RESOURCE_STATS, EMPTY_CONSOLE_STATS).

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