Moralis MCP Server

Instructions

Implementation Reference

• src/utils/execute-api-tool.ts:34-252 (handler)

  Generic execution handler for all MCP tools (including evm_getnftbycontracttraits). Validates input using Zod from JSON schema, constructs HTTP request to Moralis API endpoint based on tool definition (path, method, params), applies API key auth, executes via axios, formats JSON response or error.
  export async function executeApiTool( toolName: string, definition: McpToolDefinition, toolArgs: JsonObject, allSecuritySchemes: Record<string, any>, token?: string, ): Promise<CallToolResult> { try { // Validate arguments against the input schema let validatedArgs: JsonObject; try { const zodSchema = getZodSchemaFromJsonSchema( definition.inputSchema, toolName, ); const argsToParse = typeof toolArgs === 'object' && toolArgs !== null ? toolArgs : {}; validatedArgs = zodSchema.parse(argsToParse); } catch (error: unknown) { if (error instanceof ZodError) { const validationErrorMessage = `Invalid arguments for tool '${toolName}': ${error.errors.map((e) => `${e.path.join('.')} (${e.code}): ${e.message}`).join(', ')}`; return { content: [{ type: 'text', text: validationErrorMessage }] }; } else { const errorMessage = error instanceof Error ? error.message : String(error); return { content: [ { type: 'text', text: `Internal error during validation setup: ${errorMessage}`, }, ], }; } } // Prepare URL, query parameters, headers, and request body let urlPath = definition.pathTemplate; const queryParams: Record<string, any> = {}; const headers: Record<string, string> = { Accept: 'application/json', 'X-Moralis-Platform': 'MCP', }; let requestBodyData: any = undefined; // Apply parameters to the URL path, query, or headers definition.executionParameters.forEach((param) => { const value = validatedArgs[param.name]; if (typeof value !== 'undefined' && value !== null) { if (param.in === 'path') { urlPath = urlPath.replace( `{${param.name}}`, encodeURIComponent(String(value)), ); } else if (param.in === 'query') { queryParams[param.name] = value; } else if (param.in === 'header') { headers[param.name.toLowerCase()] = String(value); } } }); // Ensure all path parameters are resolved if (urlPath.includes('{')) { throw new Error(`Failed to resolve path parameters: ${urlPath}`); } // Construct the full URL const requestUrl = `${definition.baseUrl}${urlPath}`; // Handle request body if needed if ( definition.requestBodyContentType && typeof validatedArgs['requestBody'] !== 'undefined' ) { requestBodyData = validatedArgs['requestBody']; headers['content-type'] = definition.requestBodyContentType; } // Apply security requirements if available // Security requirements use OR between array items and AND within each object const appliedSecurity = definition.securityRequirements?.find((req) => { // Try each security requirement (combined with OR) return Object.entries(req).every(([schemeName, scopesArray]) => { const scheme = allSecuritySchemes[schemeName]; if (!scheme) return false; // API Key security (header, query, cookie) if (scheme.type === 'apiKey') { return !!token || !!Config.MORALIS_API_KEY; } return false; }); }); // If we found matching security scheme(s), apply them if (appliedSecurity) { // Apply each security scheme from this requirement (combined with AND) for (const [schemeName, scopesArray] of Object.entries(appliedSecurity)) { const scheme = allSecuritySchemes[schemeName]; // API Key security if (scheme?.type === 'apiKey') { const apiKey = token || Config.MORALIS_API_KEY; if (apiKey) { if (scheme.in === 'header') { headers[scheme.name.toLowerCase()] = apiKey; console.error( `Applied API key '${schemeName}' in header '${scheme.name}'`, ); } } } } } // Log warning if security is required but not available else if (definition.securityRequirements?.length > 0) { // First generate a more readable representation of the security requirements const securityRequirementsString = definition.securityRequirements .map((req) => { const parts = Object.entries(req) .map(([name, scopesArray]) => { const scopes = scopesArray as string[]; if (scopes.length === 0) return name; return `${name} (scopes: ${scopes.join(', ')})`; }) .join(' AND '); return `[${parts}]`; }) .join(' OR '); console.warn( `Tool '${toolName}' requires security: ${securityRequirementsString}, but no suitable credentials found.`, ); } // Prepare the axios request configuration const config: AxiosRequestConfig = { method: definition.method.toUpperCase(), url: requestUrl, params: queryParams, headers: headers, ...(requestBodyData !== undefined && { data: requestBodyData }), }; // Log request info to stderr (doesn't affect MCP output) console.error( `Executing tool "${toolName}": ${config.method} ${config.url}`, ); // Execute the request const response = await axios(config); // Process and format the response let responseText = ''; const contentType = response.headers['content-type']?.toLowerCase() || ''; // Handle JSON responses if ( contentType.includes('application/json') && typeof response.data === 'object' && response.data !== null ) { try { responseText = JSON.stringify(response.data, null, 2); } catch (e) { responseText = '[Stringify Error]'; } } // Handle string responses else if (typeof response.data === 'string') { responseText = response.data; } // Handle other response types else if (response.data !== undefined && response.data !== null) { responseText = String(response.data); } // Handle empty responses else { responseText = `(Status: ${response.status} - No body content)`; } // Return formatted response return { content: [ { type: 'text', text: `API Response (Status: ${response.status}):\n${responseText}`, }, ], }; } catch (error: unknown) { // Handle errors during execution let errorMessage: string; // Format Axios errors specially if (axios.isAxiosError(error)) { errorMessage = formatApiError(error); } // Handle standard errors else if (error instanceof Error) { errorMessage = error.message; } // Handle unexpected error types else { errorMessage = `Unexpected error: ${String(error)}`; } // Log error to stderr console.error( `Error during execution of tool '${toolName}':`, errorMessage, ); // Return error message to client return { content: [{ type: 'text', text: errorMessage }] }; } }
• src/server.ts:96-120 (registration)

  Registers the MCP CallTool handler that looks up the tool definition by name (e.g., 'evm_getnftbycontracttraits') and invokes the generic executeApiTool.
  server.setRequestHandler( CallToolRequestSchema, async (request: CallToolRequest, c): Promise<CallToolResult> => { const { name: toolName, arguments: toolArgs } = request.params; const toolDefinition = toolDefinitionMap[toolName]; if (!toolDefinition) { console.error(`Error: Unknown tool requested: ${toolName}`); return { content: [ { type: 'text', text: `Error: Unknown tool requested: ${toolName}`, }, ], }; } return executeApiTool( toolName, toolDefinition, toolArgs ?? {}, securitySchemes, c.authInfo?.token, ); }, );
• src/server.ts:85-94 (registration)

  Registers the MCP ListTools handler that returns the dynamically extracted tool list including 'evm_getnftbycontracttraits' with its schema.
  server.setRequestHandler(ListToolsRequestSchema, async () => { const toolsForClient: Tool[] = Object.values(toolDefinitionMap).map( (def) => ({ name: def.name, description: def.description, inputSchema: def.inputSchema, }), ); return { tools: toolsForClient }; });
• src/parser/extract-tools.ts:17-93 (schema)

  Dynamically generates tool definitions (name, inputSchema, description, etc.) from OpenAPI spec paths/operations, applying 'evm_' prefix to create names like 'evm_getnftbycontracttraits'.
  export function extractToolsFromApi( api: OpenAPIV3DocumentX, prefix?: string ): McpToolDefinition[] { const tools: McpToolDefinition[] = []; const usedNames = new Set<string>(); const globalSecurity = api.security || []; if (!api.paths) return tools; for (const [path, pathItem] of Object.entries(api.paths)) { if (!pathItem) continue; for (const method of Object.values(OpenAPIV3.HttpMethods)) { const operation = pathItem[method]; if (!operation) continue; // Generate a unique name for the tool let baseName = operation.operationId || generateOperationId(method, path); if (!baseName) continue; // Sanitize the name to be MCP-compatible (only a-z, 0-9, _, -) baseName = baseName .replace(/\./g, '_') .replace(/[^a-z0-9_-]/gi, '_') .toLowerCase(); let finalToolName = baseName; let counter = 1; while (usedNames.has(finalToolName)) { finalToolName = `${baseName}_${counter++}`; } usedNames.add(finalToolName); // Get or create a description const description = operation.description || operation.summary || `Executes ${method.toUpperCase()} ${path}`; const prompt = operation['x-mcp-prompt']; // Generate input schema and extract parameters const { inputSchema, parameters, requestBodyContentType } = generateInputSchemaAndDetails(operation); // Extract parameter details for execution const executionParameters = parameters.map((p) => ({ name: p.name, in: p.in, })); // Determine security requirements const securityRequirements = operation.security === null ? globalSecurity : operation.security || globalSecurity; // Create the tool definition tools.push({ name: prefix + finalToolName, description, inputSchema, method, pathTemplate: path, parameters, executionParameters, requestBodyContentType, securityRequirements, operationId: baseName, prompt, }); } } return tools; }
• src/config.ts:15-22 (helper)

  Configuration for EVM tools: prefix 'evm_' for tool names, baseUrl and specUrl for Moralis EVM API from which 'evm_getnftbycontracttraits' is derived.
  evm: { prefix: 'evm_', baseUrl: process.env.API_BASE_URL || 'https://deep-index.moralis.io/api/v2.2', specUrl: process.env.API_SPEC_URL || 'https://deep-index.moralis.io/api-docs-2.2/v2.2/swagger.json', },