Lightdash MCP Server

Instructions

Implementation Reference

• src/mcp.ts:262-290 (handler)

  Handler function that parses input with GetCustomMetricsRequestSchema, fetches custom metrics from Lightdash API endpoint '/api/v1/projects/{projectUuid}/custom-metrics', handles errors, and returns JSON results as text content.

  case 'lightdash_get_custom_metrics': {
    const args = GetCustomMetricsRequestSchema.parse(
      request.params.arguments
    );
    const { data, error } = await lightdashClient.GET(
      '/api/v1/projects/{projectUuid}/custom-metrics',
      {
        params: {
          path: {
            projectUuid: args.projectUuid,
          },
        },
      }
    );
    if (error) {
      throw new Error(
        `Lightdash API error: ${error.error.name}, ${
          error.error.message ?? 'no message'
        }`
      );
    }
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(data.results, null, 2),
        },
      ],
    };

• src/schemas.ts:41-48 (schema)

  Zod schema defining the input parameters for the tool, requiring a projectUuid (UUID string).

  export const GetCustomMetricsRequestSchema = z.object({
    projectUuid: z
      .string()
      .uuid()
      .describe(
        'The UUID of the project. You can obtain it from the project list.'
      ),
  });

• src/mcp.ts:74-78 (registration)

  Tool registration in the ListTools response, specifying name, description, and input schema converted to JSON schema.

  {
    name: 'lightdash_get_custom_metrics',
    description: 'Get custom metrics for a project',
    inputSchema: zodToJsonSchema(GetCustomMetricsRequestSchema),
  },