# Package com.google.appengine.api.channel

Provides persistent connectivity to JavaScript clients for real time messaging without the use of polling.

See: Description

- Interface Summary
  Interface | Description
  --- | ---
  ChannelService | `ChannelService` allows you to manage manage two-way connections with clients.

- Class Summary
  Class | Description
  --- | ---
  ChannelMessage | Class that represents a channel message.
  ChannelPresence | Represents presence information returned by the server.
  ChannelServiceFactory | Constructs and instance of the Channel service.

- Exception Summary
  Exception | Description
  --- | ---
  ChannelFailureException | `ChannelFailureException` is an unchecked exception that is thrown for any unexpected error that occurs while communicating with the channel service.

## Package com.google.appengine.api.channel Description

Provides persistent connectivity to JavaScript clients for real time messaging without the use of polling.

See Also:
  `ChannelService`, The Channel Java API in the Google App Engine Developer's Guide.