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Knowledge Graph (KG)

3 min read

Aside from adding LLMS.txt and files to your documentation website and using Retrieval Augmented Generation (RAG), you can add Knowledge Graphs.

A Knowledge Graph is a structured representation of information as entities (nodes) and relationships (edges) — like a network of facts about your system, APIs, concepts, and how they connect. The dataset is usually stored in a graph database. However, for simple use cases, you can represent a small knowledge graph as a local file, e.g., JSON-LD, RDF, Turtle, or CSV format, and keep it in your site’s repo for indexing or LLM/RAG purposes.

Auto-generate a Knowledge Graph

  • Use LLMs to extract entities and relationships from your docs (e.g., APIs, modules, error codes, dependencies).
  • Tools like LangChain’s KG Retriever or Haystack’s KG pipelines help integrate this.

Formats

  • RDF / Turtle (for Semantic Web)
  • JSON-LD (for structured data, LLM-readable)
  • CSV triples (subject, predicate, object)
  • GraphML or Neo4j format (for databases)

Place a knowledge-graph.jsonld or knowledge-graph.csv file in the root directory of your Documentation website or a hidden /llm/ directory. For scalable use, load it into a graph database (e.g., Neo4j, Weaviate, TerminusDB) that can be queried at retrieval time.

About the JSON-LD Format

In JSON-LD, the : separates a prefix from a term, like this:

"name": "product:name"

This means:

  • product is a prefix that maps to a URL base (defined in the "@context")
  • name is the actual property

So "product:name" becomes https://example.com/product#name (fully qualified), see example below.

Info

JSON-LD keywords:

  • @context defines the mapping between prefixes and full URIs
  • @type defines what type of thing the object is (like a class in RDF)
  • @id can optionally define a globally unique ID for an entity

Example API Reference (JSON-LD format)

Create a file: knowledge-graph.jsonld
Put it in your project root or docs/llm/ folder.

The following example represents:

  • LoginEndpoint calls JWTService and returns an AccessToken
  • JWTService is used by LoginEndpoint
{
  "@context": {
    "api": "https://example.com/api#",
    "name": "api:name",
    "type": "@type",
    "calls": "api:calls",
    "returns": "api:returns",
    "usedBy": "api:usedBy"
  },
  "@graph": [
    {
      "name": "LoginEndpoint",
      "type": "api:Endpoint",
      "calls": "JWTService",
      "returns": "AccessToken"
    },
    {
      "name": "JWTService",
      "type": "api:Service",
      "usedBy": "LoginEndpoint"
    },
    {
      "name": "AccessToken",
      "type": "api:DataObject"
    }
  ]
}

Example Product Website (JSON-LD format)

Typical entities on product websites:

  • Product components: Dashboard, Analytics, Notification System
  • User roles: Admin, Viewer, Contributor
  • Features: Real-time reports, Dark mode, Email alerts
  • Integrations: Slack, Stripe, Zapier
  • Plans: Free, Pro, Enterprise
  • Pages: home, pricing, getting-started, troubleshooting

Typical relationships on product websites:

  • offersFeature
  • requires
  • usedBy
  • hasIntegration
  • relevantFor
  • availableInPlan

Create a file: product-kg.jsonld If a user asks: “What integrations are available in the Pro plan?”, the LLM can:

  • Look up components in the ProPlan
  • Get their offersFeature
  • Check if those features have hasIntegration links
{
  "@context": {
    "product": "https://example.com/product#",
    "name": "product:name",
    "type": "@type",
    "offersFeature": "product:offersFeature",
    "hasIntegration": "product:hasIntegration",
    "availableInPlan": "product:availableInPlan",
    "relevantFor": "product:relevantFor"
  },
  "@graph": [
    {
      "name": "AnalyticsDashboard",
      "type": "product:Component",
      "offersFeature": ["RealTimeReports", "EmailAlerts"],
      "availableInPlan": ["ProPlan", "EnterprisePlan"]
    },
    {
      "name": "RealTimeReports",
      "type": "product:Feature",
      "relevantFor": "Admin"
    },
    {
      "name": "EmailAlerts",
      "type": "product:Feature",
      "hasIntegration": "Slack"
    },
    {
      "name": "Slack",
      "type": "product:Integration"
    },
    {
      "name": "ProPlan",
      "type": "product:Plan"
    },
    {
      "name": "EnterprisePlan",
      "type": "product:Plan"
    },
    {
      "name": "Admin",
      "type": "product:UserRole"
    }
  ]
}

Graph View

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