New Relic MCP Server

Instructions

Implementation Reference

• src/tools/rest/metrics.ts:110-137 (handler)

  The handler function that implements the core logic for fetching metric timeslices data for a host via New Relic REST API v2, supporting pagination and query parameters.

  async getMetricData(args: GetMetricDataArgs): Promise<unknown> {
    const client = this.restFor(args.region);
    const path = `/applications/${args.application_id}/hosts/${args.host_id}/metrics/data`;
    const query: Record<string, unknown> = { names: args.names, values: args.values };
    if (args.from) query.from = args.from;
    if (args.to) query.to = args.to;
    if (args.period) query.period = args.period;
    if (args.summarize !== undefined) query.summarize = args.summarize;
    if (args.page) query.page = args.page;
  
    const results: unknown[] = [];
    let nextUrl: string | undefined;
    let page = args.page;
    do {
      const res = await client.get<unknown>(path, page ? { ...query, page } : query);
      results.push(res.data);
      const next = res.links?.next;
      if (args.auto_paginate && next) {
        const u = new URL(next);
        const p = u.searchParams.get('page');
        page = p ? Number(p) : undefined;
        nextUrl = next;
      } else {
        nextUrl = undefined;
      }
    } while (args.auto_paginate && nextUrl);
    return { items: args.auto_paginate ? results : results[0], page };
  }

• src/tools/rest/metrics.ts:86-108 (schema)

  Defines the tool's metadata, description, and input schema for validation.

  getMetricDataTool(): Tool {
    return {
      name: 'get_metric_data_for_host',
      description: 'Get metric timeslices for metrics on a host (REST v2).',
      inputSchema: {
        type: 'object',
        properties: {
          application_id: { type: 'number' },
          host_id: { type: 'number' },
          names: { type: 'array', items: { type: 'string' } },
          values: { type: 'array', items: { type: 'string' } },
          from: { type: 'string' },
          to: { type: 'string' },
          period: { type: 'number' },
          summarize: { type: 'boolean' },
          page: { type: 'number' },
          auto_paginate: { type: 'boolean' },
          region: { type: 'string', enum: ['US', 'EU'] },
        },
        required: ['application_id', 'host_id', 'names'],
      },
    };
  }

• src/server.ts:85-87 (registration)

  Registers the tool by including its definition in the server's list of available tools.

  restMetrics.getListMetricNamesTool(),
  restMetrics.getMetricDataTool(),
  restMetrics.getListApplicationHostsTool(),

• src/server.ts:195-198 (registration)

  Registers the execution handler in the server's tool dispatcher switch statement.

  case 'get_metric_data_for_host':
    return await new RestMetricsTool().getMetricData(
      args as Parameters<RestMetricsTool['getMetricData']>[0]
    );

• src/tools/rest/metrics.ts:13-25 (schema)

  TypeScript type definition for the tool's input arguments, aligning with the inputSchema.

  type GetMetricDataArgs = {
    application_id: number;
    host_id: number;
    names: string[];
    values?: string[];
    from?: string;
    to?: string;
    period?: number;
    summarize?: boolean;
    page?: number;
    auto_paginate?: boolean;
    region?: Region;
  };