--- #https://www.notion.so/n8n/Frontmatter-432c2b8dff1f43d4b1c8d20075510fe4 contentType: explanation --- # Choose your node building approach n8n has two node-building styles, declarative and programmatic. You should use the declarative style for most nodes. This style: * Uses a JSON-based syntax, making it simpler to write, with less risk of introducing bugs. * Is more future-proof. * Supports integration with REST APIs. The programmatic style is more verbose. You must use the programmatic style for: * Trigger nodes * Any node that isn't REST-based. This includes nodes that need to call a GraphQL API and nodes that use external dependencies. * Any node that needs to transform incoming data. * Full versioning. Refer to [Node versioning](/integrations/creating-nodes/build/reference/node-versioning.md) for more information on types of versioning. ## Data handling differences The main difference between the declarative and programmatic styles is how they handle incoming data and build API requests. The programmatic style requires an `execute()` method, which reads incoming data and parameters, then builds a request. The declarative style handles this using the `routing` key in the `operations` object. Refer to [Node base file](/integrations/creating-nodes/build/reference/node-base-files/index.md) for more information on node parameters and the `execute()` method. ## Syntax differences To understand the difference between the declarative and programmatic styles, compare the two code snippets below. This example creates a simplified version of the SendGrid integration, called "FriendGrid." The following code snippets aren't complete: they emphasize the differences in the node building styles. In programmatic style: ```js import { IExecuteFunctions, INodeExecutionData, INodeType, INodeTypeDescription, IRequestOptions, } from 'n8n-workflow'; // Create the FriendGrid class export class FriendGrid implements INodeType { description: INodeTypeDescription = { displayName: 'FriendGrid', name: 'friendGrid', . . . properties: [ { displayName: 'Resource', . . . }, { displayName: 'Operation', name: 'operation', type: 'options', displayOptions: { show: { resource: [ 'contact', ], }, }, options: [ { name: 'Create', value: 'create', description: 'Create a contact', }, ], default: 'create', description: 'The operation to perform.', }, { displayName: 'Email', name: 'email', . . . }, { displayName: 'Additional Fields', // Sets up optional fields }, ], }; async execute(this: IExecuteFunctions): Promise { let responseData; const resource = this.getNodeParameter('resource', 0) as string; const operation = this.getNodeParameter('operation', 0) as string; //Get credentials the user provided for this node const credentials = await this.getCredentials('friendGridApi') as IDataObject; if (resource === 'contact') { if (operation === 'create') { // Get email input const email = this.getNodeParameter('email', 0) as string; // Get additional fields input const additionalFields = this.getNodeParameter('additionalFields', 0) as IDataObject; const data: IDataObject = { email, }; Object.assign(data, additionalFields); // Make HTTP request as defined in https://sendgrid.com/docs/api-reference/ const options: IRequestOptions = { headers: { 'Accept': 'application/json', 'Authorization': `Bearer ${credentials.apiKey}`, }, method: 'PUT', body: { contacts: [ data, ], }, url: `https://api.sendgrid.com/v3/marketing/contacts`, json: true, }; responseData = await this.helpers.httpRequest(options); } } // Map data to n8n data return [this.helpers.returnJsonArray(responseData)]; } } ``` In declarative style: ```js import { INodeType, INodeTypeDescription } from 'n8n-workflow'; // Create the FriendGrid class export class FriendGrid implements INodeType { description: INodeTypeDescription = { displayName: 'FriendGrid', name: 'friendGrid', . . . // Set up the basic request configuration requestDefaults: { baseURL: 'https://api.sendgrid.com/v3/marketing' }, properties: [ { displayName: 'Resource', . . . }, { displayName: 'Operation', name: 'operation', type: 'options', displayOptions: { show: { resource: [ 'contact', ], }, }, options: [ { name: 'Create', value: 'create', description: 'Create a contact', // Add the routing object routing: { request: { method: 'POST', url: '=/contacts', send: { type: 'body', properties: { email: {{$parameter["email"]}} } } } }, // Handle the response to contact creation output: { postReceive: [ { type: 'set', properties: { value: '={{ { "success": $response } }}' } } ] } }, ], default: 'create', description: 'The operation to perform.', }, { displayName: 'Email', . . . }, { displayName: 'Additional Fields', // Sets up optional fields }, ], } // No execute method needed } ```