# `@arcjet/headers`

[Arcjet][arcjet] extension of the Headers class. - [npm package (`@arcjet/headers`)](https://www.npmjs.com/package/@arcjet/headers) - [GitHub source code (`headers/` in `arcjet/arcjet-js`)](https://github.com/arcjet/arcjet-js/tree/main/headers) ## What is this? This is an internal utility to help us deal with [`Headers`][mdn-headers]. This exists to prevent the `cookie` header from being set and non-string values from being set. ## When should I use this? You should not use this but use `Headers` or plain objects instead. This package matches our current needs which are likely different from yours. ## Install This package is ESM only. Install with npm in Node.js: ```sh npm install @arcjet/headers ``` ## Use ```ts import { ArcjetHeaders } from "@arcjet/headers"; const headers = new ArcjetHeaders({ abc: "123" }); console.log(headers.get("abc")); // => "123" ``` ## API This package exports the identifier [`ArcjetHeaders`][api-arcjet-headers]. The default export is [`ArcjetHeaders`][api-arcjet-headers]. This package exports no [TypeScript][] types. ### `new ArcjetHeaders([init])` Creates a new `ArcjetHeaders` instance. We use this internally to prevent the `cookie` header from being set and to ensure only string values are used. ###### Parameters - `init` (`Headers | Array<[string, string]> | Record | string | undefined>`, optional) — initial headers to set ###### Returns An `ArcjetHeaders` instance that extends the standard `Headers` class. ## License [Apache License, Version 2.0][apache-license] © [Arcjet Labs, Inc.][arcjet] [arcjet]: https://arcjet.com [apache-license]: http://www.apache.org/licenses/LICENSE-2.0 [api-arcjet-headers]: #new-arcjetheadersinit [mdn-headers]: https://developer.mozilla.org/en-US/docs/Web/API/Headers [typescript]: https://www.typescriptlang.org/