Moralis MCP Server

Instructions

Implementation Reference

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

  Generic execution handler for all API-based MCP tools. For 'evm_gettoperc20tokensbypricemovers', it uses the tool's definition to build and send an HTTP request to the Moralis EVM API endpoint, validates inputs, handles auth with API key, and returns formatted JSON response.

  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)

  MCP CallTool request handler registration. Dispatches to executeApiTool based on tool name 'evm_gettoperc20tokensbypricemovers' using pre-built tool definitions from OpenAPI spec.

  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/parser/extract-tools.ts:17-93 (schema)

  Extracts tool definitions including input schemas from OpenAPI document. For EVM spec, creates definition for 'evm_gettoperc20tokensbypricemovers' from corresponding operationId 'gettoperc20tokensbypricemovers', mapping params to inputSchema.

  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/server.ts:85-94 (registration)

  MCP ListTools request handler registration. Returns tool list with names and inputSchemas, including 'evm_gettoperc20tokensbypricemovers'.

  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/server.ts:26-44 (helper)

  Builds toolDefinitionMap by fetching EVM OpenAPI spec, extracting tools with 'evm_' prefix, and storing definitions for dispatch.

  async function mapToolDefinitions(config: SchemaConfig) {
    const spec = (await getSpec(config.specUrl)) as OpenAPIV3DocumentX;
    const api = (await SwaggerParser.dereference(spec)) as OpenAPIV3DocumentX;
  
    const tools = extractToolsFromApi(api, config.prefix);
    const blacklist = Array.isArray(api['x-mcp-blacklist'])
      ? api['x-mcp-blacklist'].map((e) => `${config.prefix}${e.toLowerCase()}`)
      : [];
  
    const toolDefinitionMap: Record<string, McpToolDefinition> = {};
    for (const tool of tools) {
      if (blacklist.includes(tool.name)) continue;
      toolDefinitionMap[tool.name] = {
        ...tool,
        baseUrl: config.baseUrl,
      };
    }
    return toolDefinitionMap;
  }