E-E-A-T content-quality validator: Google policy-versioned gap detection for AI-generated content.
Post-March 2024 Google core update + November 2024 site reputation abuse update, AI-generated content without Experience / Expertise / Authoritativeness / Trustworthiness signals is buried in search. Most SEO tooling emits vague guidance ("your content needs more authority"). evidence-core emits concrete actions tied to specific Google policy versions so a creator — or a content pipeline — knows exactly what evidence is missing and what to add.
This package is the OSS core of Evidence Engine, a pre-publish content-quality gate shipped as part of Stackbilder Pro.
npm install @stackbilt/evidence-core
# or
pnpm add @stackbilt/evidence-coreimport{validateEvidence}from'@stackbilt/evidence-core';constresult=awaitvalidateEvidence({text: 'Your draft content here...',author: 'Jane Doe',authorBio: 'Senior content strategist with 10 years...',lastUpdated: '2026-04-19',aiDisclosure: 'AI-assisted, human-reviewed',},{policyVersion: 'google_november_2024_reputation',});if(result.hasGaps){for(constsuggestionofresult.suggestions){console.log(`[${suggestion.priority}] ${suggestion.pillar}:`);for(constactionofsuggestion.actions){console.log(` - ${action.action}`);console.log(` e.g. ${action.examples[0]}`);}}}Each preset maps to a real Google algorithm update. Pick the version that matches your content's risk surface.
| Version | When to use |
|---|---|
google_baseline_2023 | Historical comparison / legacy archive re-scoring |
google_march_2024_core | Scaled content abuse + helpful content guidance; lower bar than reputation preset |
google_november_2024_reputation (default) | Reputation-sensitive verticals (YMYL, review, how-to); adds editorial-process requirements |
You can also supply a custom EvidencePolicy via options.policy.
Experience — real-world first-hand signals
minCaseStudies,minOriginalVisuals,minFirstHandEvidence
Expertise — substantive, informed treatment
minCitations,minDataPoints,minUniqueInsights
Authoritativeness — signals of the author's or publisher's credibility
requiresAuthorByline,requiresAuthorBio,requiresExternalValidation,requiresEditorialProcess
Trustworthiness — transparency + source integrity
requiresLastUpdated,requiresAIDisclosure,requiresSourceAttribution
A JSON Schema for modeling an evidence asset library (case studies, customer quotes, original visuals, proprietary data, etc.) is exported at @stackbilt/evidence-core/schema:
importschemafrom'@stackbilt/evidence-core/schema' assert {type: 'json'};The schema is a reference contract; storage is left to the consumer (D1, Postgres, flat file, etc.). The companion mergeEvidence(content, evidence) helper injects library-retrieved evidence into a draft.
mergeEvidence(content, evidence) is the deterministic "inject" step of a gap-fill loop. Validate a draft, look up library assets that address the gaps, merge them into the draft, then re-draft with an LLM and re-validate. The merge itself is a pure, synchronous transformation — no LLM call, no mutation of the input, and no null coercion (absent evidence fields leave the output fields absent).
import{validateEvidence,mergeEvidence}from'@stackbilt/evidence-core';letdraft={text: 'Your draft...',author: 'Jane Doe',authorBio: 'Senior content strategist with 10 years...',};letresult=awaitvalidateEvidence(draft);while(result.hasGaps){constassets=awaitqueryEvidenceLibrary(result.gaps);// consumer-supplieddraft=mergeEvidence(draft,{caseStudies: assets.caseStudies,// [{ title, summary, url?, date? }]citations: assets.citations,// [{ url, title?, publishedDate? }]visuals: assets.visuals,// [{ url, alt, caption? }]metadata: {lastUpdated: '2026-04-19'},});draft.text=awaitllmRedraft(draft);// consumer-suppliedresult=awaitvalidateEvidence(draft);}The ./audit export provides audit trail hooks for validation and evidence-merge events. Records are shaped to be compatible with @stackbilt/audit-chain's writeRecord() — no production dependency, but integration point is well-defined.
EvidenceAuditEvent— union of 8 event types:validation.started,validation.completed,gaps.detected,assets.merged,redraft.completed,approval.granted,publish.allowed,publish.blockedEvidenceAuditRecord— audit record shape (namespace,event_type,actor,payload), matching@stackbilt/audit-chain'swriteRecord()options minuschainHead(caller supplies that when writing — see usage example below).contentIdand other event-specific fields live insidepayload, not top-level.ToAuditPayloadOptions— config for payload generation
toAuditPayload(result: ValidationResult,options: ToAuditPayloadOptions): EvidenceAuditRecordConverts a validateEvidence() result into an audit record. Records the event type based on validation outcome (gaps detected, validation completed, etc.).
toAssetsAuditPayload(evidence: MergeableEvidence,options: ToAuditPayloadOptions): EvidenceAuditRecordRecords the assets-merge event after calling mergeEvidence().
import{validateEvidence,mergeEvidence}from'@stackbilt/evidence-core';import{toAuditPayload,toAssetsAuditPayload}from'@stackbilt/evidence-core/audit';// audit-chain is optional — wire it at the app layer, not imported hereimport{writeRecord,getChainHead}from'@stackbilt/audit-chain';constcontentId='article:uuid-12345';constcontent={text: '...',author: 'Jane Doe'};// Validate and record the eventconstresult=awaitvalidateEvidence(content,{policyVersion: 'google_march_2024_core'});constrecord=toAuditPayload(result,{
contentId,contentHash: sha256(content.text),// optionalactor: 'user:operator-id',// optional, defaults to 'system:evidence-engine'});// Wire with audit-chain if availableconstchainHead=awaitgetChainHead(bindings,record.namespace);awaitwriteRecord(bindings,{ ...record, chainHead });// After merging evidence assetsconstevidence={caseStudies: [...],citations: [...]};constmergedContent=mergeEvidence(content,evidence);constassetsRecord=toAssetsAuditPayload(evidence,{ contentId });constupdatedHead=awaitgetChainHead(bindings,assetsRecord.namespace);awaitwriteRecord(bindings,{ ...assetsRecord,chainHead: updatedHead});- Default namespace:
content:{contentId}(e.g.,content:article-123) - Multi-tenant:
tenant:{tenantId}:content:{contentId}(e.g.,tenant:t-456:content:article-123) - Override via
ToAuditPayloadOptions.namespace
@stackbilt/audit-chain is not declared as a dependency (peer or otherwise) — evidence-core ships with zero runtime dependencies. Consumers wire audit records into a chain at the application layer.
Pillar counters use regex patterns (case-study markers, citation links, first-hand-experience phrases, data points, etc.) — intentional design trade-off: deterministic, fast, no LLM dependency, runs in any environment including Cloudflare Workers. Consumers who want LLM-grade semantic counting should layer that on top.