MediaKeySession

This represents a media key session.

For more information, see https://www.w3.org/TR/encrypted-media/#mediakeysession-interface.

Extends

• EventTarget

Properties

closed

readonly closed: Promise<void>

Signals when the object becomes closed as a result of the Session Closed algorithm being run.

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-closed.

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expiration

readonly expiration: number

The expiration time for all key(s) in the session, or NaN if no such time exists or if the license explicitly never expires, as determined by the CDM.

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-expiration.

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keyStatuses

readonly keyStatuses: MediaKeyStatusMap

A reference to a read-only map of key IDs known to the session to the current status of the associated key. Each entry has a unique key ID.

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-keystatuses.

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onkeystatuseschange()

onkeystatuseschange: (this, ev) => any

Event handler for the "keystatuseschange" event.

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-onkeystatuseschange.

Parameters

this

MediaKeySession

ev

Event

Returns

any

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onmessage()

onmessage: (this, ev) => any

Event handler for the "message" event.

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-onmessage.

Parameters

this

MediaKeySession

ev

MediaKeyMessageEvent

Returns

any

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sessionId

readonly sessionId: string

The Session ID for this object and the associated key(s) or license(s).

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-sessionid.

Methods

addEventListener()

Call Signature

addEventListener<K>(type, listener, options?): void

Adds an even listener.

Type Parameters

• K extends keyof MediaKeySessionEventMap

Parameters

type

K

Type of event.

listener

(this, ev) => any

Event handler.

options?

Ignored.

boolean

AddEventListenerOptions

Returns

void

Overrides

EventTarget.addEventListener

Call Signature

addEventListener(type, listener, options?): void

Adds an even listener.

Parameters

type

string

Type of event.

listener

EventListener

Event handler.

options?

Ignored.

boolean

AddEventListenerOptions

Returns

void

Overrides

EventTarget.addEventListener

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close()

close(): Promise<void>

Indicates that the application no longer needs the session and the CDM should release any resources associated with the session and close it. Persisted data is not released or cleared.

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-close.

Returns

Promise<void>

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dispatchEvent()?

optional dispatchEvent(event): boolean

Dispatches an event to the target

Parameters

event

Event

The event which signals an occurrenceo.

Returns

boolean

TODO

Add and define in the implementations, keep it optional for now.

Inherited from

EventTarget.dispatchEvent

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generateRequest()

generateRequest(initDataType, initData): Promise<void>

Generates a license request based on the initData. A message of type "license-request" or "individualization-request" will always be queued if the algorithm succeeds and the promise is resolved.

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-generaterequest.

Parameters

initDataType

string

The Initialization Data Type of the initData.

initData

ArrayBuffer

Initialization Data.

Returns

Promise<void>

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load()

load(sessionId): Promise<boolean>

Loads the data stored for the specified session into this object.

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-load

Parameters

sessionId

string

The Session ID of the session to load.

Returns

Promise<boolean>

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remove()

remove(): Promise<void>

Removes all license(s) and key(s) associated with the session. For persistent session types, other session data will be cleared as defined for each session type once a release message acknowledgment is processed by update().

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-remove.

Returns

Promise<void>

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removeEventListener()

removeEventListener(type, listener, options?): void

Removes an event listener.

Parameters

type

string

The event to listen to.

listener

EventListener

The Event Handler function to be removed.

options?

Ignore.

boolean

EventListenerOptions

Returns

void

Inherited from

EventTarget.removeEventListener

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update()

update(response): Promise<void>

Provides messages, including licenses, to the CDM.

For more information, see https://www.w3.org/TR/encrypted-media/#dom-mediakeysession-update.

Parameters

response

ArrayBuffer

A message to be provided to the CDM.

Returns

Promise<void>

Promise that will get fulfilled when method executes successfully. The contents are Key System-specific. It must not contain executable code.

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Last updated: Sep 30, 2025