# Functions

**Twilio Functions** is a serverless environment that lets you create event-driven Twilio applications that scale with your business.

## Key features

* **Secure by default**: Ensures that only Twilio requests execute your code.
* **Serverless**: Offload infrastructure management to Twilio.
* **Autoscaling**: Adds capacity to meet your application's demand.
* **Native Twilio integration**: Access Functions directly in the Console with a pre-initialized [Twilio Node.js SDK](https://github.com/twilio/twilio-node).
* **Familiar**: Develop in an environment powered by [Node.js 22](https://nodejs.org/en/blog/release/v22.14.0).

## How Functions work

![Diagram showing HTTP requests and responses between a web app, TwiML, Twilio services, and third-party services.](https://docs-resources.prod.twilio.com/c53e91e471d18c0a2043c49be617066815b536bc99ae2b95fcfc977428f41620.png)

Twilio Functions replaces your need to find hosting or stand up a server to serve TwiML or any other HTTP-based responses. With Functions, you no longer maintain or scale web infrastructure. Twilio manages and scales it for you.

Typical use cases include manipulating voice calls, serving up tokens for our mobile SDKs, or invoking the Twilio REST API in response to an event, such as an inbound SMS.

## Get started with Serverless and Twilio Functions

The Twilio Functions and Assets Editor displays Functions, Assets, dependencies, environment variables, and debugging tools in a single window. You can upload and create [Assets](/docs/serverless/functions-assets/assets). You can access all your Functions to edit them in multiple tabs simultaneously.

![Twilio Functions Console showing code editor with example TwiML function and logs pane.](https://docs-resources.prod.twilio.com/402ccb797944a0f0d4ed448b70b590c62d5878466ef6e3276a1abe9d476ce6cf.png)

The following code examples help you start building with Twilio Functions and Assets.

### Learn the basics for handling SMS, MMS, and phone calls

* [Receive inbound SMS](/docs/serverless/functions-assets/quickstart/receive-sms)
* [Send SMS and MMS](/docs/serverless/functions-assets/quickstart/send-sms-and-mms)
* [Receive incoming phone calls](/docs/serverless/functions-assets/quickstart/receive-call)
* [Make a Call](/docs/serverless/functions-assets/quickstart/make-a-call)

### Learn how to leverage APIs

* [Make an API request](/docs/serverless/functions-assets/quickstart/api-request)

### Learn how headers and cookies can add extra functionality and security

* [Enable CORS between Flex Plugins and Functions](/docs/serverless/functions-assets/quickstart/enabling-cors-between-flex-plugins-and-functions)
* [Validate Webhook requests from SendGrid](/docs/serverless/functions-assets/quickstart/validate-webhook-requests-from-sendgrid)
* [Manage application state with cookies](/docs/serverless/functions-assets/quickstart/cookies-state)
* [Protect your Function with Basic Auth](/docs/serverless/functions-assets/quickstart/basic-auth)
* [Protect your Function with JSON Web Token (JWT)](/docs/serverless/functions-assets/quickstart/json-web-token)

### Learn how to integrate Functions with Twilio Studio

* [Use the Run Function widget in Studio](/docs/serverless/functions-assets/quickstart/run-function-studio-widget)
* [Add delay](/docs/serverless/functions-assets/quickstart/add-delay)
* [Normalize telephone numbers](/docs/serverless/functions-assets/quickstart/normalize-telephone-numbers)

### Learn other common use cases

* [Use Twilio Sync to manage real-time data in your applications](/docs/serverless/functions-assets/quickstart/real-time-data-sync)
* [Determine carrier, phone number type, and caller info](/docs/serverless/functions-assets/quickstart/lookup-carrier-and-caller-info)
* [Time of day routing](/docs/serverless/functions-assets/quickstart/time-of-day-routing)
* [Prevent blocked numbers from calling your application](/docs/serverless/functions-assets/quickstart/blocked-numbers)
* [Display Node.js and Twilio server-side SDK versions](/docs/serverless/functions-assets/quickstart/display-versions)

## Next steps

After you understand what Functions can do, learn how requests reach your Function.

If you want to jump directly to the available tools and values inside a Function, skip ahead.

* Learn about [request flow and limitations for your Twilio Function](/docs/serverless/functions-assets/functions/request-flow)
* Learn about [the execution process, handler method, and response building](/docs/serverless/functions-assets/functions/invocation)