WebTransport

BYOB reader support

The close() method of the WebTransport interface closes an ongoing WebTransport session.

The closed read-only property of the WebTransport interface returns a promise that resolves when the transport is closed.

The congestionControl read-only property of the WebTransport interface indicates the application's preference for either high throughput or low-latency when sending data.

The createBidirectionalStream() method of the WebTransport interface asynchronously opens and returns a bidirectional stream.

`options.sendOrder` parameter

The createUnidirectionalStream() method of the WebTransport interface asynchronously opens a unidirectional stream.

BYOB reader support

`options.sendOrder` parameter

The datagrams read-only property of the WebTransport interface returns a WebTransportDatagramDuplexStream instance that can be used to send and receive datagrams — unreliable data transmission.

The getStats() method of the WebTransport interface asynchronously returns an object containing HTTP/3 connection statistics.

The incomingBidirectionalStreams read-only property of the WebTransport interface represents one or more bidirectional streams opened by the server. Returns a ReadableStream of WebTransportBidirectionalStream objects. Each one can be used to reliably read data from the server and write data back to it.

The incomingUnidirectionalStreams read-only property of the WebTransport interface represents one or more unidirectional streams opened by the server. Returns a ReadableStream of WebTransportReceiveStream objects. Each one can be used to reliably read data from the server.

The ready read-only property of the WebTransport interface returns a promise that resolves when the transport is ready to use.

The reliability read-only property of the WebTransport interface indicates whether the connection supports reliable transports only, or whether it also supports unreliable transports (such as UDP).

The WebTransport() constructor creates a new WebTransport object instance.

`options.allowPooling` parameter

`options.congestionControl` parameter

`options.requireUnreliable` parameter

`options.serverCertificateHashes` parameter

The WebTransportBidirectionalStream interface of the WebTransport API represents a bidirectional stream created by a server or a client that can be used for reliable transport. Provides access to a WebTransportReceiveStream for reading incoming data, and a WebTransportSendStream for writing outgoing data.

The readable read-only property of the WebTransportBidirectionalStream interface returns a WebTransportReceiveStream instance that can be used to reliably read incoming data.

Returns `WebTransportReceiveStream` (earlier spec returned `ReadableStream`)

The writable read-only property of the WebTransportBidirectionalStream interface returns a WebTransportSendStream instance that can be used to write outgoing data.

Returns `WebTransportSendStream` (earlier spec returned `WritableStream`)

The WebTransportDatagramDuplexStream interface of the WebTransport API represents a duplex stream that can be used for unreliable transport of datagrams between client and server. Provides access to a ReadableStream for reading incoming datagrams, a WritableStream for writing outgoing datagrams, and various settings and statistics related to the stream.

BYOB reader support

The incomingHighWaterMark property of the WebTransportDatagramDuplexStream interface gets or sets the high water mark for incoming chunks of data — this is the maximum size, in chunks, that the incoming ReadableStream's internal queue can reach before it is considered full. See Internal queues and queuing strategies for more information.

The incomingMaxAge property of the WebTransportDatagramDuplexStream interface gets or sets the maximum age for incoming datagrams, in milliseconds.

The maxDatagramSize read-only property of the WebTransportDatagramDuplexStream interface returns the maximum allowable size of outgoing datagrams, in bytes, that can be written to WebTransportDatagramDuplexStream.writable.

The outgoingHighWaterMark property of the WebTransportDatagramDuplexStream interface gets or sets the high water mark for outgoing chunks of data — this is the maximum size, in chunks, that the outgoing WritableStream's internal queue can reach before it is considered full. See Internal queues and queuing strategies for more information.

The outgoingMaxAge property of the WebTransportDatagramDuplexStream interface gets or sets the maximum age for outgoing datagrams, in milliseconds.

The readable read-only property of the WebTransportDatagramDuplexStream interface returns a ReadableStream instance that can be used to unreliably read incoming datagrams from the stream.

The WebTransportError interface of the WebTransport API represents an error related to the API, which can arise from server errors, network connection problems, or client-initiated abort operations (for example, arising from a WritableStream.abort() call).

The source read-only property of the WebTransportError interface returns an enumerated value indicating the source of the error.

The streamErrorCode read-only property of the WebTransportError interface returns a number in the range 0-255 indicating the application protocol error code for this error, or null if one is not available.

The WebTransportError() constructor creates a new WebTransportError object instance.

The WebTransportReceiveStream interface of the WebTransport API is a ReadableStream that can be used to read from an incoming unidirectional or bidirectional WebTransport stream.

The getStats() method of the WebTransportReceiveStream interface asynchronously returns an object containing statistics for the current stream.

The WebTransportSendStream interface of the WebTransport API is a specialized WritableStream that is used to send outbound data in both unidirectional or bidirectional WebTransport streams.

The getStats() method of the WebTransportSendStream interface asynchronously returns an object containing statistics for the current stream.

The sendOrder property of the WebTransportSendStream interface indicates the send priority of this stream relative to other streams for which the value has been set.