Microsoft Azure Documentation

Create your first Azure Functions HTTP-triggered function

This article guides you through creating your first Azure Functions HTTP-triggered function. Azure Functions is a serverless compute service that enables you to run code on-demand without explicitly provisioning or managing infrastructure.

Prerequisites

Step 1: Create a new Functions project

Open your terminal or command prompt, and navigate to a directory where you want to create your project. Then, run the following command to create a new Functions project:

func init MyFunctionProj --worker-runtime node --docker

Replace MyFunctionProj with the name of your project. The --worker-runtime specifies the language of your Functions, and --docker generates a Dockerfile for containerization.

Step 2: Create a new HTTP-triggered function

Navigate into your project directory:

cd MyFunctionProj

Then, create a new HTTP-triggered function:

func new --name HttpTriggerFunction --template "HTTP trigger" --authlevel "anonymous"

This command creates a new function named HttpTriggerFunction with an HTTP trigger template. --authlevel "anonymous" means the function can be called without an API key.

Step 3: Understand the function code

Open the HttpTriggerFunction folder in your code editor. You'll find a few files, including index.js (or your language's equivalent) and function.json.

function.json

This file defines the function's bindings, including the HTTP trigger:

                
{
  "bindings": [
    {
      "authLevel": "anonymous",
      "type": "httpTrigger",
      "direction": "in",
      "name": "req",
      "methods": [
        "get",
        "post"
      ]
    },
    {
      "type": "http",
      "direction": "out",
      "name": "res"
    }
  ]
}

index.js

This file contains the actual code for your function:

                
module.exports = async function (context, req) {
    context.log('JavaScript HTTP trigger function processed a request.');

    const name = (req.query.name || (req.body && req.body.name));
    const responseMessage = name
        ? 'Hello, ' + name + '!'
        : "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response.";

    context.res = {
        status: 200,
        body: responseMessage
    };
};

Note: The code above is for Node.js. The structure and specifics will vary slightly for other languages like C#, Python, or Java.

Step 4: Run your function locally

In your terminal, within your project directory, run the following command to start the Functions host:

func start

The output will show the local URL for your HTTP-triggered function. It typically looks like http://localhost:7071/api/HttpTriggerFunction.

Step 5: Test your function

Open your web browser and navigate to the local URL. You can also append a name query parameter:

http://localhost:7071/api/HttpTriggerFunction?name=AzureFunctionsUser

You should see a personalized greeting. If you navigate without a name, you'll see the default message.

Next steps