> For the complete documentation index, see [llms.txt](https://docs.n8n.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.n8n.io/connect/create-nodes/plan-your-node/choose-a-node-building-style.md).

# Choose a node building style

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](/connect/create-nodes/build-your-node/reference/versioning.md) for more information on types of versioning.

## Data handling differences <a href="#data-handling-differences" id="data-handling-differences"></a>

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](/connect/create-nodes/build-your-node/reference/base-files.md) for more information on node parameters and the `execute()` method.

## Syntax differences <a href="#syntax-differences" id="syntax-differences"></a>

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<INodeExecutionData[][]> {
    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
}
```