Cookies

Cookie reading and writing, built on Bun's native cookie primitives.

Cookies extends Bun.CookieMap, so it keeps the whole native API — get, set, delete, iteration — and adds the two constructions the framework needs: parsing an inbound Cookie header and parsing outbound Set-Cookie headers back into a map.

The two header formats are not interchangeable, which is why they get separate entry points: a Cookie header is a list of name/value pairs on one line with no attributes, while each Set-Cookie header is a single cookie carrying its own Path, Max-Age, HttpOnly and the rest.

Cookies

class

class Cookies extends Bun.CookieMap

A cookie map with header-parsing constructors.

Everything Bun.CookieMap offers is available unchanged; the two static methods are the additions. Use Cookies.fromHeader for what a client sent and Cookies.fromSetCookieHeaders for what a server is sending back — reading a response's own cookies, or following them in a client.

Cookies.constructor()

constructor(...args: ConstructorParameters<typeof Bun.CookieMap>)

Creates a cookie map, forwarding to the native constructor.

Bun.CookieMap is a native class that ignores new.target, so instances come back with the base prototype and none of the subclass members attached. The prototype is reattached here, which is what makes subclassing work at all.

Parameters

• args — The native Bun.CookieMap constructor arguments.

Cookies.fromHeader()

static fromHeader(cookieHeader: string): Cookies

Builds a map from an inbound Cookie header.

Parameters

• cookieHeader — The raw Cookie header value, as sent by the client.

Returns — The cookies it carried. Repeated names resolve to the last occurrence.

Cookies.fromSetCookieHeaders()

static fromSetCookieHeaders(headers: string[]): Cookies

Builds a map from outbound Set-Cookie headers, preserving each cookie's attributes.

Parameters

• headers — The raw Set-Cookie values, one per cookie.

Returns — The cookies they describe. Repeated names resolve to the last occurrence.

parseSetCookieHeaders

function

function parseSetCookieHeaders(headers: string[]): Array<Bun.Cookie>;

Parses Set-Cookie header values into individual cookies, attributes included.

Each header carries exactly one cookie, so no splitting is needed — unlike parseCookieHeader, which has to break one header into many pairs.

Parameters

• headers — The raw Set-Cookie header values, one per cookie. Use Headers.getSetCookie() to obtain them; a plain get collapses repeated headers into one string and loses the boundaries.

Returns — The parsed cookies, in the order given.