Prometheus MCP Server

Instructions

Implementation Reference

• src/tools.ts:93-99 (handler)

  Handler logic for 'prom_query' tool: validates input arguments using isPromQueryArgs and executes the query via prometheusClient.query.

  case 'prom_query': {
    if (!isPromQueryArgs(args)) {
      throw new Error('Invalid arguments for prom_query');
    }
    const { query, time, includes } = args;
    result = await prometheusClient.query(query, time, includes);
    break;

• src/tools.ts:11-23 (registration)

  Registration of the 'prom_query' tool in the exported tools array, defining name, description, and input schema.

  {
    name: 'prom_query',
    description: 'Execute a PromQL instant query',
    inputSchema: {
      type: 'object',
      properties: {
        query: { type: 'string', description: 'PromQL query expression' },
        time: { type: 'string', description: 'Evaluation timestamp (optional)' },
        includes: { type: 'array', items: { type: 'string' }, description: 'Metric properties to include in response (optional)' },
      },
      required: ['query'],
    },
  },

• src/types.ts:10-14 (schema)

  TypeScript interface defining the expected arguments for prom_query, matching the input schema.

  export interface PromQueryArgs {
    query: string;
    time?: string;
    includes?: string[];
  }

• src/tools.ts:66-68 (helper)

  Type guard helper function to validate if arguments match PromQueryArgs structure.

  function isPromQueryArgs(args: unknown): args is PromQueryArgs {
    return typeof args === 'object' && args !== null && 'query' in args;
  }