MCP *arr Server

Instructions

Implementation Reference

• src/index.ts:1617-1642 (handler)

  MCP tool handler: checks if Prowlarr client configured, calls getIndexerStats(), formats stats with counts, per-indexer details, and totals into JSON response

  case "prowlarr_get_stats": {
    if (!clients.prowlarr) throw new Error("Prowlarr not configured");
    const stats = await clients.prowlarr.getIndexerStats();
    return {
      content: [{
        type: "text",
        text: JSON.stringify({
          count: stats.indexers.length,
          indexers: stats.indexers.map(s => ({
            name: s.indexerName,
            queries: s.numberOfQueries,
            grabs: s.numberOfGrabs,
            failedQueries: s.numberOfFailedQueries,
            failedGrabs: s.numberOfFailedGrabs,
            avgResponseTime: s.averageResponseTime + 'ms',
          })),
          totals: {
            queries: stats.indexers.reduce((sum, s) => sum + s.numberOfQueries, 0),
            grabs: stats.indexers.reduce((sum, s) => sum + s.numberOfGrabs, 0),
            failedQueries: stats.indexers.reduce((sum, s) => sum + s.numberOfFailedQueries, 0),
            failedGrabs: stats.indexers.reduce((sum, s) => sum + s.numberOfFailedGrabs, 0),
          },
        }, null, 2),
      }],
    };
  }

• src/index.ts:570-577 (schema)

  Tool schema: defines name, description, and empty input schema (no parameters required)

    name: "prowlarr_get_stats",
    description: "Get indexer statistics (queries, grabs, failures)",
    inputSchema: {
      type: "object" as const,
      properties: {},
      required: [],
    },
  }

• src/index.ts:535-579 (registration)

  Tool registration: adds prowlarr_get_stats to TOOLS array conditionally if Prowlarr client is configured

  if (clients.prowlarr) {
    TOOLS.push(
      {
        name: "prowlarr_get_indexers",
        description: "Get all configured indexers in Prowlarr",
        inputSchema: {
          type: "object" as const,
          properties: {},
          required: [],
        },
      },
      {
        name: "prowlarr_search",
        description: "Search across all Prowlarr indexers",
        inputSchema: {
          type: "object" as const,
          properties: {
            query: {
              type: "string",
              description: "Search query",
            },
          },
          required: ["query"],
        },
      },
      {
        name: "prowlarr_test_indexers",
        description: "Test all indexers and return their health status",
        inputSchema: {
          type: "object" as const,
          properties: {},
          required: [],
        },
      },
      {
        name: "prowlarr_get_stats",
        description: "Get indexer statistics (queries, grabs, failures)",
        inputSchema: {
          type: "object" as const,
          properties: {},
          required: [],
        },
      }
    );
  }

• src/arr-client.ts:978-982 (helper)

  ProwlarrClient helper: performs API GET request to /indexerstats endpoint to retrieve raw indexer statistics

   * Get indexer statistics
   */
  async getIndexerStats(): Promise<{ indexers: IndexerStats[] }> {
    return this['request']<{ indexers: IndexerStats[] }>('/indexerstats');
  }

• src/arr-client.ts:935-948 (schema)

  TypeScript interface defining the structure of indexer stats data returned from Prowlarr API

  export interface IndexerStats {
    id: number;
    indexerId: number;
    indexerName: string;
    averageResponseTime: number;
    numberOfQueries: number;
    numberOfGrabs: number;
    numberOfRssQueries: number;
    numberOfAuthQueries: number;
    numberOfFailedQueries: number;
    numberOfFailedGrabs: number;
    numberOfFailedRssQueries: number;
    numberOfFailedAuthQueries: number;
  }