APRS.fi MCP Server

Instructions

Implementation Reference

• index.ts:116-170 (handler)

  Core handler function that implements the get_aprs_history tool by querying the APRS.fi API for historical position data of a callsign over the last N hours.
  async getPositionHistory( callsign: string, apiKey?: string, lastHours: number = 24 ): Promise<APRSPosition[]> { const keyToUse = apiKey || this.apiKey; if (!keyToUse) { throw new APRSError('APRS API key not provided. Use /set-api-key command or provide apiKey parameter.'); } if (!callsign?.trim()) { throw new APRSError('Callsign is required'); } const params = new URLSearchParams({ name: callsign.trim().toUpperCase(), what: 'loc', apikey: keyToUse, format: 'json', last: lastHours.toString() }); try { const response = await fetch(`${this.baseUrl}?${params}`); if (!response.ok) { throw new APRSError( `APRS API request failed: ${response.status} ${response.statusText}`, response.status ); } const data: APRSResponse = await response.json(); if (data.result !== 'ok') { throw new APRSError(`APRS API error: ${data.result}`); } return data.entries.map(entry => ({ ...entry, timestamp: entry.timestamp * 1000, })).sort((a, b) => a.timestamp - b.timestamp); } catch (error) { if (error instanceof APRSError) { throw error; } if (error instanceof TypeError && error.message.includes('fetch')) { throw new APRSError('Network error: Unable to connect to APRS.fi API. Check your internet connection.'); } throw new APRSError(`Unexpected error: ${error instanceof Error ? error.message : 'Unknown error'}`); } }
• index.ts:394-407 (handler)

  MCP CallToolRequestSchema handler case for get_aprs_history that invokes the service method and returns the result as JSON text content.
  case 'get_aprs_history': const history = await this.aprsService.getPositionHistory( args.callsign as string, args.apiKey as string, args.lastHours as number ); return { content: [ { type: 'text', text: JSON.stringify(history, null, 2), }, ], };
• index.ts:306-328 (registration)

  Tool registration in ListToolsRequestSchema response, defining the name, description, and input schema for get_aprs_history.
  { name: 'get_aprs_history', description: 'Get position history for a callsign with time range', inputSchema: { type: 'object', properties: { callsign: { type: 'string', description: 'The callsign to look up', }, apiKey: { type: 'string', description: 'APRS.fi API key (optional if set via /set-api-key)', }, lastHours: { type: 'number', description: 'Number of hours to look back (default: 24)', default: 24, }, }, required: ['callsign'], }, },
• index.ts:29-35 (schema)

  Type definition for the API response structure used in get_aprs_history.
  interface APRSResponse { command: string; result: string; what: string; found: number; entries: APRSPosition[]; }
• index.ts:15-27 (schema)

  Type definition for individual APRS position data returned by the get_aprs_history tool.
  interface APRSPosition { name: string; callsign: string; lat: number; lng: number; altitude?: number; timestamp: number; comment?: string; speed?: number; course?: number; symbol?: string; path?: string; }