Norwegian Business Registry MCP Server

Instructions

Implementation Reference

• src/brreg-mcp-server.ts:95-97 (handler)

  Core handler function in BrregApiClient class that makes the HTTP request to the BRREG API to fetch detailed information about a specific sub-entity (underenhet) by its organization number.

  async getSubEntity(orgNumber: string) {
    return this.makeRequest(`/enhetsregisteret/api/underenheter/${orgNumber}`);
  }

• src/brreg-mcp-server.ts:264-270 (schema)

  JSON schema defining the input parameters for the get_sub_entity tool: requires a 9-digit organisasjonsnummer string.

  inputSchema: {
    type: "object",
    properties: {
      organisasjonsnummer: { type: "string", description: "9-digit organization number" }
    },
    required: ["organisasjonsnummer"]
  }

• src/brreg-mcp-server.ts:261-271 (registration)

  Tool registration in the ListTools response, including name, description, and input schema.

  {
    name: "get_sub_entity",
    description: "Get detailed information about a specific Norwegian business sub-entity",
    inputSchema: {
      type: "object",
      properties: {
        organisasjonsnummer: { type: "string", description: "9-digit organization number" }
      },
      required: ["organisasjonsnummer"]
    }
  },

• src/brreg-mcp-server.ts:448-458 (handler)

  MCP server handler case that extracts the organization number from tool arguments, calls the apiClient handler, and returns the JSON-formatted response as text content.

  case "get_sub_entity":
    const { organisasjonsnummer: subOrgNum } = request.params.arguments as { organisasjonsnummer: string };
    const subEntity = await apiClient.getSubEntity(subOrgNum);
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(subEntity, null, 2),
        },
      ],
    };