CoinStats MCP Server

Instructions

Implementation Reference

• src/tools/toolFactory.ts:21-77 (handler)

  Generic MCP tool handler registered for 'get-coin-chart-by-id'. For API tools, constructs the API call using config.endpoint ('/coins/{coinId}/charts'), method ('GET'), and passes parameters to universalApiHandler which handles path replacement and query params.
  server.tool(config.name, config.description, config.parameters, async (params: Record<string, any>) => { // Handle local operations if (config.isLocal) { // Handle specific local tools if (config.name === 'save-share-token') { await saveToCache('shareToken', params.shareToken); return { content: [ { type: 'text', text: 'Share token saved successfully', }, ], }; } if (config.name === 'get-share-token') { const shareToken = await getFromCache('shareToken'); return { content: [ { type: 'text', text: shareToken ? shareToken : 'No share token found in cache', isError: !shareToken, }, ], }; } // Future local tools can be added here // Default response for unhandled local tools return { content: [ { type: 'text', text: 'Operation completed', }, ], }; } // Handle API operations const basePath = config.basePath || COINSTATS_API_BASE; const method = config.method || 'GET'; // Methods that typically have a request body const bodyMethods = ['POST', 'PUT', 'PATCH', 'DELETE']; // For GET/DELETE requests, all params go in the URL // For POST/PUT/PATCH, send params as the body if (bodyMethods.includes(method.toUpperCase())) { return universalApiHandler(basePath, config.endpoint, method, {}, params); } else { return universalApiHandler(basePath, config.endpoint, method, params); } });
• src/tools/toolConfigs.ts:92-101 (schema)

  Tool schema definition: name, description, endpoint, method, and Zod-parameter schema for input validation (coinId: string, period: enum).
  { name: 'get-coin-chart-by-id', description: 'Get chart data for a specific cryptocurrency based on its unique identifier, specifying different time ranges.', endpoint: '/coins/{coinId}/charts', method: 'GET', parameters: { coinId: z.string().describe('The identifier of coin, which you received from /coins call response.'), period: z.enum(['all', '24h', '1w', '1m', '3m', '6m', '1y']).describe('Time period for chart data'), }, },
• src/index.ts:17-18 (registration)

  Registers the MCP server tools by calling registerTools with allToolConfigs, which includes 'get-coin-chart-by-id'.
  // Register all tools from configurations registerTools(server, allToolConfigs);
• src/services/request.ts:35-97 (helper)

  Helper function called by the tool handler: replaces path params like {coinId}, adds remaining params as query, makes authenticated fetch to CoinStats API using makeRequestCsApi, returns JSON string in MCP format or error.
  export async function universalApiHandler<T>( basePath: string, endpoint: string, method: string = 'GET', params: Record<string, any> = {}, body?: any ): Promise<{ content: Array<{ type: 'text'; text: string; isError?: boolean }>; }> { try { // Handle path parameters - replace {paramName} in endpoint with actual values let processedEndpoint = endpoint; let processedParams = { ...params }; // Find all path parameters in the endpoint (e.g., {coinId}, {id}, {type}) const pathParamMatches = endpoint.match(/\{([^}]+)\}/g); if (pathParamMatches) { for (const match of pathParamMatches) { const paramName = match.slice(1, -1); // Remove { and } if (processedParams[paramName] !== undefined) { // Replace the placeholder with the actual value processedEndpoint = processedEndpoint.replace(match, processedParams[paramName]); // Remove the parameter from query params since it's now part of the path delete processedParams[paramName]; } else { throw new Error(`Required path parameter '${paramName}' is missing`); } } } // MCP clients might not support '~' in parameter names, so we replace '-' with '~' specifically for the /coins endpoint before making the request. if (endpoint === '/coins') { processedParams = Object.entries(processedParams).reduce((acc, [key, value]) => { acc[key.replace(/-/g, '~')] = value; return acc; }, {} as Record<string, any>); } const url = `${basePath}${processedEndpoint}`; const data = await makeRequestCsApi<T>(url, method, processedParams, body); if (!data) { return { content: [{ type: 'text', text: 'Something went wrong', isError: true }], }; } return { content: [ { type: 'text', text: JSON.stringify(data), }, ], }; } catch (error) { return { content: [{ type: 'text', text: `Error: ${error}`, isError: true }], }; } }
• src/services/request.ts:4-32 (helper)

  Core HTTP request helper: performs fetch to CoinStats API with API key header, handles query params and body, returns parsed JSON or null on error.
  export async function makeRequestCsApi<T>(url: string, method: string = 'GET', params: Record<string, any> = {}, body?: any): Promise<T | null> { const headers = { 'X-API-KEY': COINSTATS_API_KEY, 'Content-Type': 'application/json', }; try { // Build request options const options: RequestInit = { method, headers }; // Add body for non-GET requests if provided if (method !== 'GET' && body) { options.body = JSON.stringify(body); } // Add query params for all requests const queryParams = new URLSearchParams(params); const queryString = queryParams.toString(); const urlWithParams = queryString ? `${url}?${queryString}` : url; const response = await fetch(urlWithParams, options); if (!response.ok) { throw new Error(`HTTP error! status: ${response.status}`); } return (await response.json()) as T; } catch (error) { return null; } }