Incoming webhook integrations
An incoming webhook allows a third-party service to push data to Zulip when
something happens. There are several ways to set up an incoming webhook in
Zulip:
In an incoming webhook integration, the third-party service's
"outgoing webhook" feature sends an HTTP POST to a special URL when
it has something for you, and then the Zulip "incoming webhook"
integration handles that incoming data to format and send a message in
Zulip.
New official Zulip webhook integrations can take just a few hours to
write, including tests and documentation, if you use the right
process.
Quick guide
-
Set up the
Zulip development environment.
-
Use Zulip's JSON integration,
https://webhook.site/, or a similar site to capture an example
webhook payload from the third-party service. Create a
zerver/webhooks/<mywebhook>/fixtures/ directory, and add the
captured JSON payload as a test fixture.
-
Create an Integration object, and add it to the WEBHOOK_INTEGRATIONS
list in zerver/lib/integrations.py. Search for WebhookIntegration in that
file to find an existing one to copy.
-
Write a draft webhook handler in zerver/webhooks/<mywebhook>/view.py. There
are a lot of examples in the zerver/webhooks/ directory that you can copy.
We recommend templating from a short one, like zendesk.
-
Write a test for your fixture in zerver/webhooks/<mywebhook>/tests.py.
Run the test for your integration like this:
tools/test-backend zerver/webhooks/<mywebhook>/
Iterate on debugging the test and webhooks handler until it all
works.
-
Capture payloads for the other common types of POSTs the third-party
service will make, and add tests for them; usually this part of the
process is pretty fast.
-
Document the integration in zerver/webhooks/<mywebhook>/doc.md(required for
getting it merged into Zulip). You can use existing documentation, like
this one,
as a template. This should not take more than 15 minutes, even if you don't speak English
as a first language (we'll clean up the text before merging).
Hello world walkthrough
Check out the detailed walkthrough for step-by-step
instructions.
Checklist
Files that need to be created
Select a name for your incoming webhook and use it consistently. The examples
below are for a webhook named MyWebHook.
zerver/webhooks/mywebhook/__init__.py: Empty file that is an obligatory
part of every python package. Remember to git add it.zerver/webhooks/mywebhook/view.py: The main webhook integration function,
called api_mywebhook_webhook, along with any necessary helper functions.zerver/webhooks/mywebhook/fixtures/message_type.json: Sample JSON payload data
used by tests. Add one fixture file per type of message supported by your
integration.zerver/webhooks/mywebhook/tests.py: Tests for your webhook.zerver/webhooks/mywebhook/doc.md: End-user documentation explaining
how to add the integration.static/images/integrations/logos/mywebhook.svg: A square logo for the
platform/server/product you are integrating. Used on the documentation
pages as well as the sender's avatar for messages sent by the integration.static/images/integrations/mywebhook/001.png: A screenshot of a message
sent by the integration, used on the documentation page. This can be
generated by running tools/screenshots/generate-integration-docs-screenshot --integration mywebhook.static/images/integrations/bot_avatars/mywebhook.png: A square logo for the
platform/server/product you are integrating which is used to create the avatar
for generating screenshots with. This can be generated automatically from
static/images/integrations/logos/mywebhook.svg by running
tools/setup/generate_integration_bots_avatars.py.
Files that need to be updated
zerver/lib/integrations.py: Add your integration to
WEBHOOK_INTEGRATIONS. This will automatically register a
URL for the incoming webhook of the form api/v1/external/mywebhook and
associate it with the function called api_mywebhook_webhook in
zerver/webhooks/mywebhook/view.py. Also add your integration to
DOC_SCREENSHOT_CONFIG. This will allow you to automatically generate
a screenshot for the documentation by running
tools/screenshots/generate-integration-docs-screenshot --integration mywebhook.
Common Helpers
- If your integration will receive a test webhook payload, you can use
get_setup_webhook_message to create our standard message for test payloads.
You can import this from zerver/lib/webhooks/common.py, and it will generate
a message like this: "GitHub webhook is successfully configured! 🎉"
General advice
-
Consider using our Zulip markup to make the output from your
integration especially attractive or useful (e.g., emoji, Markdown
emphasis, or @-mentions).
-
Use topics effectively to ensure sequential messages about the same
thing are threaded together; this makes for much better consumption
by users. E.g., for a bug tracker integration, put the bug number in
the topic for all messages; for an integration like Nagios, put the
service in the topic.
-
Integrations that don't match a team's workflow can often be
uselessly spammy. Give careful thought to providing options for
triggering Zulip messages only for certain message types, certain
projects, or sending different messages to different channels/topics,
to make it easy for teams to configure the integration to support
their workflow.
-
Consistently capitalize the name of the integration in the
documentation and the Client name the way the vendor does. It's OK
to use all-lower-case in the implementation.
-
Sometimes it can be helpful to contact the vendor if it appears they
don't have an API or webhook we can use; sometimes the right API
is just not properly documented.
-
A helpful tool for testing your integration is
UltraHook, which allows you to receive webhook
calls via your local Zulip development environment. This enables you to do end-to-end
testing with live data from the service you're integrating and can help you
spot why something isn't working or if the service is using custom HTTP
headers.
URL specification
The base URL for an incoming webhook integration bot, where
INTEGRATION_NAME is the name of the specific webhook integration and
API_KEY is the API key of the bot created by the user for the
integration, is:
https://chat2.ifi.lmu.de/api/v1/external/INTEGRATION_NAME?api_key=API_KEY
The list of existing webhook integrations can be found by browsing the
Integrations documentation or in
zerver/lib/integrations.py at WEBHOOK_INTEGRATIONS.
Parameters accepted in the URL include:
api_key (required)
The API key of the bot created by the user for the integration. To get a
bot's API key, see the API keys documentation.
stream
The channel for the integration to send notifications to. Can be either
the channel ID or the URL-encoded channel name. By default
the integration will send direct messages to the bot's owner.
topic
The topic in the specified channel for the integration to send
notifications to. The topic should also be URL-encoded.
By default the integration will have a topic configured for channel
messages.
only_events, exclude_events
Some incoming webhook integrations support these parameters to filter
which events will trigger a notification. You can append either
&only_events=["event_a","event_b"] or
&exclude_events=["event_a","event_b"] (or both, with different events)
to the URL, with an arbitrary number of supported events.
You can use UNIX-style wildcards like * to include multiple events.
For example, test* matches every event that starts with test.
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