@types/express-session

property domain

domain?: string;

property expires

expires?: Date;

property httpOnly

httpOnly?: boolean;

property maxAge

maxAge?: number;

property originalMaxAge

originalMaxAge: number;

• Returns the original maxAge (time-to-live), in milliseconds, of the session cookie.

property path

path?: string;

property sameSite

sameSite?: boolean | 'lax' | 'strict' | 'none';

property secure

secure?: boolean | 'auto';

property signed

signed?: boolean;

method all

all: (
    callback: (err: any, obj?: { [sid: string]: SessionData }) => void
) => void;

method clear

clear: (callback?: (err?: any) => void) => void;

method destroy

destroy: (sid: string, callback?: (err?: any) => void) => void;

method get

get: (
    sid: string,
    callback: (err: any, session?: SessionData | null) => void
) => void;

method length

length: (callback: (err: any, length?: number) => void) => void;

method set

set: (sid: string, session: SessionData, callback?: (err?: any) => void) => void;

method touch

touch: (sid: string, session: SessionData, callback?: () => void) => void;

property cookie

cookie: Cookie;

• Each session has a unique cookie object accompany it. This allows you to alter the session cookie per visitor. For example we can set req.session.cookie.expires to false to enable the cookie to remain for only the duration of the user-agent.

property id

id: string;

• Each session has a unique ID associated with it. This property is an alias of req.sessionID and cannot be modified. It has been added to make the session ID accessible from the session object.

method destroy

destroy: (callback: (err: any) => void) => this;

• Destroys the session and will unset the req.session property. Once complete, the callback will be invoked.

method regenerate

regenerate: (callback: (err: any) => void) => this;

• To regenerate the session simply invoke the method. Once complete, a new SID and Session instance will be initialized at req.session and the callback will be invoked.

method reload

reload: (callback: (err: any) => void) => this;

• Reloads the session data from the store and re-populates the req.session object. Once complete, the callback will be invoked.

method resetMaxAge

resetMaxAge: () => this;

• Resets the cookie's maxAge to originalMaxAge

  See Also

  • Cookie

method save

save: (callback?: (err: any) => void) => this;

• Save the session back to the store, replacing the contents on the store with the contents in memory (though a store may do something else - consult the store's documentation for exact behavior).

  This method is automatically called at the end of the HTTP response if the session data has been altered (though this behavior can be altered with various options in the middleware constructor). Because of this, typically this method does not need to be called. There are some cases where it is useful to call this method, for example: redirects, long-lived requests or in WebSockets.

method touch

touch: () => this;

• Updates the maxAge property. Typically this is not necessary to call, as the session middleware does this for you.

method all

all: (
    callback: (
        err: any,
        obj?: SessionData[] | { [sid: string]: SessionData }
    ) => void
) => void;

• Returns all sessions in the store

method clear

clear: (callback?: (err?: any) => void) => void;

• Delete all sessions from the store.

method createSession

createSession: (
    req: express.Request,
    session: SessionData
) => Session & SessionData;

method destroy

abstract destroy: (sid: string, callback?: (err?: any) => void) => void;

• Destroys the session with the given session ID.

method get

abstract get: (
    sid: string,
    callback: (err: any, session?: SessionData | null) => void
) => void;

• Gets the session from the store given a session ID and passes it to callback.

  The session argument should be a Session object if found, otherwise null or undefined if the session was not found and there was no error. A special case is made when error.code === 'ENOENT' to act like callback(null, null).

method length

length: (callback: (err: any, length?: number) => void) => void;

• Returns the amount of sessions in the store.

method load

load: (sid: string, callback: (err: any, session?: SessionData) => any) => void;

method regenerate

regenerate: (req: express.Request, callback: (err?: any) => any) => void;

method set

abstract set: (
    sid: string,
    session: SessionData,
    callback?: (err?: any) => void
) => void;

• Upsert a session in the store given a session ID and SessionData

method touch

touch: (sid: string, session: SessionData, callback?: () => void) => void;

• "Touches" a given session, resetting the idle timer.

property domain

domain?: string | undefined;

• Specifies the value for the Domain Set-Cookie attribute. By default, no domain is set, and most clients will consider the cookie to apply to only the current domain.

property encode

encode?: ((val: string) => string) | undefined;

property expires

expires?: Date | null | undefined;

• Specifies the Date object to be the value for the Expires Set-Cookie attribute. By default, no expiration is set, and most clients will consider this a "non-persistent cookie" and will delete it on a condition like exiting a web browser application.

  If both expires and maxAge are set in the options, then the last one defined in the object is what is used.

  See Also

  • maxAge

  Deprecated

  The expires option should not be set directly; instead only use the maxAge option

property httpOnly

httpOnly?: boolean | undefined;

• Specifies the boolean value for the HttpOnly Set-Cookie attribute. When truthy, the HttpOnly attribute is set, otherwise it is not. By default, the HttpOnly attribute is set.

  Be careful when setting this to true, as compliant clients will not allow client-side JavaScript to see the cookie in document.cookie.

property maxAge

maxAge?: number | undefined;

• Specifies the number (in milliseconds) to use when calculating the Expires Set-Cookie attribute. This is done by taking the current server time and adding maxAge milliseconds to the value to calculate an Expires datetime. By default, no maximum age is set.

  If both expires and maxAge are set in the options, then the last one defined in the object is what is used. maxAge should be preferred over expires.

  See Also

  • expires

property partitioned

partitioned?: boolean | undefined;

• Specifies the boolean value for the [Partitioned Set-Cookie](https://tools.ietf.org/html/draft-cutler-httpbis-partitioned-cookies/) attribute. When truthy, the Partitioned attribute is set, otherwise it is not. By default, the Partitioned attribute is not set.

  **Note** This is an attribute that has not yet been fully standardized, and may change in the future. This also means many clients may ignore this attribute until they understand it.

property path

path?: string | undefined;

• Specifies the value for the Path Set-Cookie attribute. By default, this is set to '/', which is the root path of the domain.

property priority

priority?: 'low' | 'medium' | 'high' | undefined;

• Specifies the string to be the value for the [Priority Set-Cookie attribute](https://tools.ietf.org/html/draft-west-cookie-priority-00#section-4.1).

  - 'low' will set the Priority attribute to Low. - 'medium' will set the Priority attribute to Medium, the default priority when not set. - 'high' will set the Priority attribute to High.

  More information about the different priority levels can be found in [the specification](https://tools.ietf.org/html/draft-west-cookie-priority-00#section-4.1).

  **Note** This is an attribute that has not yet been fully standardized, and may change in the future. This also means many clients may ignore this attribute until they understand it.

property sameSite

sameSite?: boolean | 'lax' | 'strict' | 'none' | undefined;

• Specifies the boolean or string to be the value for the SameSite Set-Cookie attribute. - true will set the SameSite attribute to Strict for strict same site enforcement. - false will not set the SameSite attribute. - lax will set the SameSite attribute to Lax for lax same site enforcement. - none will set the SameSite attribute to None for an explicit cross-site cookie. - strict will set the SameSite attribute to Strict for strict same site enforcement.

  More information about the different enforcement levels can be found in the specification.

  **Note:** This is an attribute that has not yet been fully standardized, and may change in the future. This also means many clients may ignore this attribute until they understand it.

property secure

secure?: boolean | 'auto' | undefined;

• Specifies the boolean value for the Secure Set-Cookie attribute. When truthy, the Secure attribute is set, otherwise it is not. By default, the Secure attribute is not set. Be careful when setting this to true, as compliant clients will not send the cookie back to the server in the future if the browser does not have an HTTPS connection.

  Please note that secure: true is a **recommended option**. However, it requires an https-enabled website, i.e., HTTPS is necessary for secure cookies. If secure is set, and you access your site over HTTP, **the cookie will not be set**.

  The cookie.secure option can also be set to the special value auto to have this setting automatically match the determined security of the connection. Be careful when using this setting if the site is available both as HTTP and HTTPS, as once the cookie is set on HTTPS, it will no longer be visible over HTTP. This is useful when the Express "trust proxy" setting is properly setup to simplify development vs production configuration.

  If you have your node.js behind a proxy and are using secure: true, you need to set "trust proxy" in express. Please see the [README](https://github.com/expressjs/session) for details.

  Please see the [README](https://github.com/expressjs/session) for an example of using secure cookies in production, but allowing for testing in development based on NODE_ENV.

property signed

signed?: boolean | undefined;

property cookie

cookie: Cookie;

property cookie

cookie?: CookieOptions | undefined;

• Settings object for the session ID cookie.

  See Also

  • CookieOptions

property name

name?: string | undefined;

• The name of the session ID cookie to set in the response (and read from in the request). The default value is 'connect.sid'.

  Note if you have multiple apps running on the same hostname (this is just the name, i.e. localhost or 127.0.0.1; different schemes and ports do not name a different hostname), then you need to separate the session cookies from each other. The simplest method is to simply set different names per app.

property proxy

proxy?: boolean | undefined;

• Trust the reverse proxy when setting secure cookies (via the "X-Forwarded-Proto" header). The default value is undefined.

  - true: The X-Forwarded-Proto header will be used. - false: All headers are ignored and the connection is considered secure only if there is a direct TLS/SSL connection. - undefined: Uses the "trust proxy" setting from express

property resave

resave?: boolean | undefined;

• Forces the session to be saved back to the session store, even if the session was never modified during the request. Depending on your store this may be necessary, but it can also create race conditions where a client makes two parallel requests to your server and changes made to the session in one request may get overwritten when the other request ends, even if it made no changes (this behavior also depends on what store you're using).

  The default value is true, but using the default has been deprecated, as the default will change in the future. Please research into this setting and choose what is appropriate to your use-case. Typically, you'll want false.

  How do I know if this is necessary for my store? The best way to know is to check with your store if it implements the touch method. If it does, then you can safely set resave: false. If it does not implement the touch method and your store sets an expiration date on stored sessions, then you likely need resave: true.

property rolling

rolling?: boolean | undefined;

• Force the session identifier cookie to be set on every response. The expiration is reset to the original maxAge, resetting the expiration countdown. The default value is false.

  With this enabled, the session identifier cookie will expire in maxAge *since the last response was sent* instead of in maxAge *since the session was last modified by the server*. This is typically used in conjuction with short, non-session-length maxAge values to provide a quick timeout of the session data with reduced potential of it occurring during on going server interactions.

  Note that when this option is set to true but the saveUninitialized option is set to false, the cookie will not be set on a response with an uninitialized session. This option only modifies the behavior when an existing session was loaded for the request.

  See Also

  • saveUninitialized

property saveUninitialized

saveUninitialized?: boolean | undefined;

• Forces a session that is "uninitialized" to be saved to the store. A session is uninitialized when it is new but not modified. Choosing false is useful for implementing login sessions, reducing server storage usage, or complying with laws that require permission before setting a cookie. Choosing false will also help with race conditions where a client makes multiple parallel requests without a session.

  The default value is true, but using the default has been deprecated, as the default will change in the future. Please research into this setting and choose what is appropriate to your use-case.

  **If you are using express-session in conjunction with PassportJS:** Passport will add an empty Passport object to the session for use after a user is authenticated, which will be treated as a modification to the session, causing it to be saved. This has been fixed in PassportJS 0.3.0.

property secret

secret: CipherKey | CipherKey[];

• This is the secret used to sign the session ID cookie. The secret can be any type of value that is supported by Node.js crypto.createHmac (like a string or a Buffer). This can be either a single secret, or an array of multiple secrets. If an array of secrets is provided, only the first element will be used to sign the session ID cookie, while all the elements will be considered when verifying the signature in requests. The secret itself should be not easily parsed by a human and would best be a random set of characters.

  A best practice may include: * The use of environment variables to store the secret, ensuring the secret itself does not exist in your repository. * Periodic updates of the secret, while ensuring the previous secret is in the array.

  Using a secret that cannot be guessed will reduce the ability to hijack a session to only guessing the session ID (as determined by the genid option).

  Changing the secret value will invalidate all existing sessions. In order to rotate the secret without invalidating sessions, provide an array of secrets, with the new secret as first element of the array, and including previous secrets as the later elements.

  Note HMAC-256 is used to sign the session ID. For this reason, the secret should contain at least 32 bytes of entropy.

property store

store?: Store | undefined;

• The session store instance, defaults to a new MemoryStore instance.

  See Also

  • MemoryStore

property unset

unset?: 'destroy' | 'keep' | undefined;

• Control the result of unsetting req.session (through delete, setting to null, etc.). - destroy: The session will be destroyed (deleted) when the response ends. - keep: The session in the store will be kept, but modifications made during the request are ignored and not saved. 'keep'

method genid

genid: (req: express.Request) => string;

• Function to call to generate a new session ID. Provide a function that returns a string that will be used as a session ID. The function is given the request as the first argument if you want to use some value attached to it when generating the ID.

  The default value is a function which uses the uid-safe library to generate IDs. Be careful to generate unique IDs so your sessions do not conflict.

type SessionStore

type SessionStore = session.Store & { generate: (req: Request) => void };