ChainFETCH MCP Server

Instructions

Implementation Reference

• index.js:716-718 (handler)

  Handler logic for the get_transaction_info tool: extracts the transaction hash from arguments and calls the makeRequest method to fetch data from the ChainFETCH API endpoint /api/v1/ethereum/transactions/{transaction}
  case 'get_transaction_info': const { transaction } = args; return await this.makeRequest(`/api/v1/ethereum/transactions/${transaction}`, 'GET', {}, null, token);
• index.js:254-267 (registration)

  Registration of the get_transaction_info tool in the MCP server's tool list, defining its name, description, and input schema requiring a 'transaction' string parameter
  { name: 'get_transaction_info', description: 'Get detailed information about a specific transaction', inputSchema: { type: 'object', properties: { transaction: { type: 'string', description: 'The transaction hash to get info for', }, }, required: ['transaction'], }, },
• index.js:257-265 (schema)

  Input schema definition for get_transaction_info tool, specifying an object with a required 'transaction' string property
  inputSchema: { type: 'object', properties: { transaction: { type: 'string', description: 'The transaction hash to get info for', }, }, required: ['transaction'],
• index.js:634-682 (helper)

  Shared helper method makeRequest used by get_transaction_info (and other tools) to make authenticated HTTP requests to the ChainFETCH API, handling token, parameters, and errors
  async makeRequest(endpoint, method = 'GET', params = {}, body = null, token = null) { const chainfetchToken = token || process.env.CHAINFETCH_API_TOKEN; if (!chainfetchToken) { throw new McpError( ErrorCode.InvalidRequest, 'CHAINFETCH_API_TOKEN is required' ); } const url = new URL(`${API_BASE_URL}${endpoint}`); // Add query parameters for GET requests if (method === 'GET' && Object.keys(params).length > 0) { Object.entries(params).forEach(([key, value]) => { if (value !== undefined && value !== null) { if (Array.isArray(value)) { value.forEach(v => url.searchParams.append(`${key}[]`, v)); } else { url.searchParams.append(key, value.toString()); } } }); } const fetchOptions = { method, headers: { 'Authorization': `Bearer ${chainfetchToken}`, 'Content-Type': 'application/json', }, }; if (body && method !== 'GET') { fetchOptions.body = JSON.stringify(body); } const response = await fetch(url.toString(), fetchOptions); if (!response.ok) { const errorText = await response.text(); throw new McpError( ErrorCode.InternalError, `API request failed: ${response.status} ${response.statusText} - ${errorText}` ); } return await response.json(); }