ChainFETCH MCP Server

Instructions

Implementation Reference

• index.js:507-525 (schema)

  Schema definition for the 'search_smart_contracts_semantic' tool, including input schema with query (required) and optional limit.

  {
    name: 'search_smart_contracts_semantic',
    description: 'Semantic search for smart contracts using AI-powered vector similarity matching',
    inputSchema: {
      type: 'object',
      properties: {
        query: {
          type: 'string',
          description: 'The query to search for',
        },
        limit: {
          type: 'integer',
          description: 'The number of results to return (default: 10)',
          default: 10,
        },
      },
      required: ['query'],
    },
  },

• index.js:759-760 (handler)

  Handler for 'search_smart_contracts_semantic' tool: proxies the request to the ChainFetch API endpoint '/api/v1/ethereum/smart-contracts/semantic_search' using GET with provided arguments.

  case 'search_smart_contracts_semantic':
    return await this.makeRequest('/api/v1/ethereum/smart-contracts/semantic_search', 'GET', args, null, token);

• index.js:634-682 (helper)

  Shared helper method 'makeRequest' used by all tools, including this one, to make authenticated API calls to ChainFetch service.

  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();
  }

• index.js:612-632 (registration)

  Registration of CallToolRequestSchema handler, which dispatches to handleToolCall based on tool name, enabling execution of 'search_smart_contracts_semantic'.

    this.server.setRequestHandler(CallToolRequestSchema, async (request) => {
      const { name, arguments: args } = request.params;
  
      try {
        const result = await this.handleToolCall(name, args, this.currentToken);
        return {
          content: [
            {
              type: 'text',
              text: JSON.stringify(result, null, 2),
            },
          ],
        };
      } catch (error) {
        throw new McpError(
          ErrorCode.InternalError,
          `Tool execution failed: ${error.message}`
        );
      }
    });
  }