Essentials Plugin

Learn about the default plugin that powers core functions like publishing, querying, and verifying Knowledge Assets.

The DKG Node Essentials Plugin ships preinstalled with every DKG Node. It provides the baseline tools, resources, and APIs you’ll use to publish and retrieve verifiable knowledge on the OriginTrail DKG. It’s also the reference implementation for including Source Knowledge Assets in tool responses, so users can see which verifiable knowledge from the DKG powered an answer.

💡Tip: Use DKG Essentials as your starting toolkit. You can customize these tools or use them as blueprints for your own plugins.

What’s included

• DKG Knowledge Asset create tool - basic too to publish Knowledge assets from a JSON-LD object with public or private visibility

• DKG Knowledge Asset get tool - retrieve a Knowledge asset by it's UAL.

Publishing Knowledge assets with the "public" visibility, will replicate their content to the entirety of the DKG - making it publicly visible. When creating private knowledge assets, their content never leaves your node - only knowledge asset registration material (such as the cryptographic hash and UALs) will be published publicly.

🧱 Resources (MCP)

• Knowledge Asset (KA) resource — resolve a KA UAL.

• Knowledge Collection (KC) resource — resolve a KC UAL.

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Tool reference

Below is a consistent structure you can reuse for every tool: Purpose → Inputs → Returns → Example → Notes.

1) DKG Knowledge Asset create

Purpose Publish a single Knowledge Asset (KA) or a single Knowledge Collection (KC) to the DKG.

Inputs

• content (string, required) — a JSON-LD string (e.g., Schema.org-based) representing a KA or KC.

• privacy (string, optional) — "public" or "private", defaults to "private" if no input is provided.

Returns

All tools return an MCP-formatted payload:

• content (array) — human-readable messages. This tool returns:

  • a success line,

  • the UAL, and

  • a DKG Explorer link derived from the UAL.

Example input (JSON-LD)

{
  "@context": "https://schema.org/",
  "@type": "CreativeWork",
  "@id": "urn:first-dkg-ka:info:hello-dkg",
  "name": "Hello DKG",
  "description": "My first Knowledge Asset on the Decentralized Knowledge Graph!"
}

Typical response

Knowledge Asset collection successfully created.

UAL: did:dkg:otp:20430/0xABCDEF0123456789/12345/67890
DKG Explorer link: https://dkg-testnet.origintrail.io/explore?ual=did:dkg:otp:20430/0xABCDEF0123456789/12345/67890

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2) DKG Knowledge Asset get

Purpose Fetch a KA or KC by UAL.

Inputs

• ual (string, required) — the KA or KC UAL.

Returns

All tools return an MCP-formatted payload:

• content (array) — one item with pretty-printed JSON (as text) containing:

  • assertion — the JSON-LD content of the KA/KC

  • operation — retrieval info: operationId and status (e.g., COMPLETED)

Example input (UAL)

did:dkg:otp:20430/0xABCDEF0123456789/12345/67890

Typical response

{
  "assertion": [
    {
      "@id": "urn:ka:example",
      "http://schema.org/name": [
        {
          "@value": "DKG Example KA"
        }
      ],
      "http://schema.org/description": [
        {
          "@value": "The best KA example on the DKG"
        }
      ],
      "@type": [
        "http://schema.org/CreativeWork"
      ]
    }
  ],
  "operation": {
    "get": {
      "operationId": "3951dd30-4781-4584-a3f2-4116ce26e8d2",
      "status": "COMPLETED"
    }
  }
}

Coming soon (preview)

• DKG query & retrieve - generate/execute Schema.org-based SPARQL queries on the DKG.

• Document → JSON/Markdown - convert PDFs/Word/TXT/… into JSON/Markdown for downstream processing.

• JSON/Markdown → JSON-LD - transform structured text into a schema.org knowledge graph ready for publishing.

Source Knowledge Assets in tool responses

You can attach source Knowledge Assets to any MCP tool response, allowing the DKG Node Agent (and other agents you might use with your DKG Node) to display which Knowledge Assets were used to form the answer.

Use the helper withSourceKnowledgeAssets from the plugin’s utils submodule to include source Knowledge Assets along with your other tool responses:

import { withSourceKnowledgeAssets } from "@dkg/plugin-dkg-essentials/utils";

// Some code ...

mcp.registerTool(
  "tool name...",
  {
    title: "Tool name",
    description: "Tool description",
    inputSchema: { /* expected input variables and format */ },
  },
  async (params) => {
    // Your tool code here
    return {
      content: [{type: "text", text: "My tool response..."}],
    };
    
    return withSourceKnowledgeAssets({
      content: [{type: "text", text: "My tool response..."}],
    }, [
      { title: "KA 1", issuer: "OriginTrail", ual: "did:dkg..." },
      { title: "KA 2", issuer: "OriginTrail", ual: "did:dkg..." },
      { title: "KA 3", issuer: "OriginTrail", ual: "did:dkg..." },
    ]);
  }
);

💡Tip: To see the source Knowledge Assets when using agents other than the DKG Node Agent (e.g., VS Code, Cursor, etc.), you will need to adjust your prompt to ask for them to be shown in the response (i.e, "Please include source Knowledge Assets in the response if there are any").

You can also check the packages/plugin-example to see how this works first-hand.

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Customize & extend

• Tune the essentials — adjust defaults (e.g., privacy, retry/finality settings) or validate inputs for your domain.

• Use as a scaffold — copy the patterns (tool registration, response helpers, resource resolvers) to build new tools and full plugins.

• Compose with other plugins — chain tools into end-to-end agentic pipelines.

Builders are encouraged to customize DKG Essentials to fit their use case, and to use these tools as the basis for creating new, domain-specific capabilities.

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Next step: Creating custom plugins for your node Want more than the basics? Next, we’ll show you how to build your own plugins — integrating APIs, adding new tools, and tailoring your node’s capabilities to your specific use case.