Clients in Zulip

zerver.models.Client is Zulip's analogue of the HTTP User-Agent header (and is populated from User-Agent). It exists for use in analytics and other places to provide human-readable summary data about "which Zulip client" was used for an operation (e.g. was it the Android app, the desktop app, or a bot?).

In general, it shouldn't be used for anything controlling the behavior of Zulip; it's primarily intended to assist debugging.

Analytics

A Client is used to sort messages into client categories such as ZulipElectron on the /stats page. For more information see, Analytics.

Integrations

Generally, integrations in Zulip should declare a unique User-Agent, so that it's easy to figure out which integration is involved when debugging an issue. For incoming webhook integrations, we do that convenentialy via the auth decorators (as we will describe shortly); other integrations generally should set the first User-Agent element on their HTTP requests to something of the form ZulipIntegrationName/1.2 so that they are categorized properly.

The api_key_only_webhook_view auth decorator, used for most incoming webhooks, accepts the name of the integration as an argument and uses it to generate a client name that it adds to the request (Django HttpRequest) object as request.client.

In most integrations, request.client is then passed to check_send_stream_message, where it is used to keep track of which client sent the message (which in turn is used by analytics). For more information, see the webhook walkthrough.