# Web APIs

The **JavaScript Runtime Environment** is a set of APIs that are available as tools for the development of functions.

You can deploy projects using the Azion Edge Infrastructure, and automatically provision what is needed for your code to run on a low latency rate, closer to the users.

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## WinterTC Compliance

Azion participates in [WinterTC (TC55)](https://wintertc.org/), an Ecma International Technical Committee that standardizes a [minimum common API](https://min-common-api.proposal.wintertc.org) for web-interoperable server-side JavaScript runtimes. This participation ensures:

- **API interoperability**: Code written for Azion Runtime follows the same standards as other major runtimes.
- **Standards alignment**: Azion collaborates with WHATWG, W3C, and other standards bodies.
- **Portability**: Functions built on WinterTC-compliant APIs work consistently across platforms.

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## Network APIs

[addEventListener](/en/documentation/products/applications/functions/runtime-apis/javascript/add-eventlistener/)

[Fetch](/en/documentation/products/applications/functions/runtime-apis/javascript/fetch/)

[FetchEvent](/en/documentation/products/applications/functions/runtime-apis/javascript/fetch-event/)

[Request](/en/documentation/products/applications/functions/runtime-apis/javascript/request/)

[Response](/en/documentation/products/applications/functions/runtime-apis/javascript/response/)

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## Encoding APIs

[Encoding](/en/documentation/products/applications/functions/runtime-apis/javascript/encoding/)

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## Web Stream APIs

[TransformStream](/en/documentation/products/applications/functions/runtime-apis/javascript/transform-stream/)

[ReadableStream](/en/documentation/products/applications/functions/runtime-apis/javascript/readable-stream/)

[WritableStream](/en/documentation/products/applications/functions/runtime-apis/javascript/writable-stream/)

[ReadableStreamBYOBReader](/en/documentation/products/applications/functions/runtime-apis/javascript/readable-byob-reader/)

[ReadableStreamDefaultReader](/en/documentation/products/applications/functions/runtime-apis/javascript/readable-default-reader/)

[WritableStreamDefaultWriter](/en/documentation/products/applications/functions/runtime-apis/javascript/stream-default-writer/)

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## Web Standards APIs

[URLPattern](/en/documentation/products/applications/functions/runtime-apis/javascript/url-pattern/)

[StructuredClone](/en/documentation/products/applications/functions/runtime-apis/javascript/structured-clone/)

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## V8 Primitives

[WebAssembly](/en/documentation/products/applications/functions/runtime-apis/javascript/webassembly/)

[Intl](/en/documentation/products/applications/functions/runtime-apis/javascript/intl/)

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## Web Crypto APIs

[Crypto](/en/documentation/products/applications/functions/runtime-apis/javascript/crypto/)

[CryptoKey](/en/documentation/products/applications/functions/runtime-apis/javascript/crypto-key/)

[SubtleCrypto](/en/documentation/products/applications/functions/runtime-apis/javascript/subtle-crypto/)

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## EventTarget

[EventTarget](/en/documentation/products/applications/functions/runtime-apis/javascript/event-target/)

## EdgeRuntime property

The EdgeRuntime property can be accessed in different ways:

```js
    if (typeof EdgeRuntime !== 'string') {
    // Your logic here.
    }
```

```js
    if (typeof globalThis.EdgeRuntime !== 'string') {
    // Your logic here.
    }
```

```js
   if (typeof self.EdgeRuntime !== 'string') {
    // Your logic here.
   }
```

## Supported types

For a complete list of the Azion Runtime supported types, go to [Azion Runtime supported types](/en/documentation/products/applications/functions/runtime-apis/javascript/azion-runtime-globals/).