HTTP in

#  What are Http-in nodes used for in Node-RED

The "HTTP In" node in Node-RED is a core node that allows you to create an HTTP endpoint within your flow. It essentially sets up an HTTP server that listens for incoming HTTP requests on a specified URL path and HTTP method (e.g., GET, POST). When a request is received at this endpoint, it triggers the flow and allows you to process the request and generate a response using other nodes in the flow. you can send any type of data as a response whether it is html page, JSON, string, etc.

The baseurl will be the URL of the Node-RED instance at which your flow is deployed or the URL of the Node-RED editor.

#  Configuring http-in node

  • Method: Specify the HTTP method (e.g., GET, POST, PUT, DELETE) that the node should listen for, for more information on Http request methods.
  • URL: Define the endpoint at which it should listen. The path should look like "/test", and you can also set parameters like "/test/:id" to access them using msg.params.id.

#  Sending response

Note: This node does not send any response to the request. The flow must include an HTTP Response node to complete the request.

#  Examples

  1. In the example flow below, we have an HTTP In node configured with the GET method and "/test" as the URL path. This node returns an HTML page as a response when a request is received.
  1. In the example flow below, we have an HTTP In node configured to return the todo item as a JSON object stored in the global context, associated with the requested ID provided as a request parameter.
  1. In the example flow below, we have an HTTP In node configured with the POST method and "/todo" as the URL path. When a POST request containing a todo JSON object is received, it stores it in the todo list within the global context.

#  Output

  • payload: For a GET request, contains an object of any query string parameters. Otherwise, contains the body of the HTTP request.
  • req object: An HTTP request object. This object contains multiple properties that provide information about the request.
    • body: The body of the incoming request. The format will depend on the request.
    • headers: An object containing the HTTP request headers.
    • query: An object containing any query string parameters.
    • params: An object containing any route parameters.
    • cookies: An object containing the cookies for the request.
    • files: If enabled within the node, an object containing any files uploaded as part of a POST request.
  • res object: An HTTP response object. This property should not be used directly;

Node Documentation

Creates an HTTP end-point for creating web services.

Outputs

payload
For a GET request, contains an object of any query string parameters. Otherwise, contains the body of the HTTP request.
reqobject
An HTTP request object. This object contains multiple properties that provide information about the request.
  • body - the body of the incoming request. The format will depend on the request.
  • headers - an object containing the HTTP request headers.
  • query - an object containing any query string parameters.
  • params - an object containing any route parameters.
  • cookies - an object containing the cookies for the request.
  • files - if enabled within the node, an object containing any files uploaded as part of a POST request.
resobject
An HTTP response object. This property should not be used directly; the HTTP Response node documents how to respond to a request. This property must remain attached to the message passed to the response node.

Details

The node will listen on the configured path for requests of a particular type. The path can be fully specified, such as /user, or include named parameters that accept any value, such as /user/:name. When named parameters are used, their actual value in a request can be accessed under msg.req.params.

For requests that include a body, such as a POST or PUT, the contents of the request is made available as msg.payload.

If the content type of the request can be determined, the body will be parsed to any appropriate type. For example, application/json will be parsed to its JavaScript object representation.

Note: this node does not send any response to the request. The flow must include an HTTP Response node to complete the request.