# 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:
* Use our [REST API](/api/rest) endpoint for [sending
messages](/api/send-message). This works great for internal tools
or cases where the third-party tool wants to control the formatting
of the messages in Zulip.
* Use one of our supported [integration
frameworks](/integrations/meta-integration), such as the
[Slack-compatible incoming webhook](/integrations/doc/slack_incoming),
[Zapier integration](/integrations/doc/zapier), or
[IFTTT integration](/integrations/doc/ifttt).
* Implementing an incoming webhook integration (detailed on this page),
where all the logic for formatting the Zulip messages lives in the
Zulip server. This is how most of [Zulip's official
integrations](/integrations/) work, because they enable Zulip to
support third-party services that just have an "outgoing webhook"
feature (without the third party needing to do any work specific to
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](https://zulip.readthedocs.io/en/latest/development/overview.html).
* Use [Zulip's JSON integration](/integrations/doc/json),
, or a similar site to capture an example
webhook payload from the third-party service. Create a
`zerver/webhooks//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//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//tests.py`.
Run the test for your integration like this:
```
tools/test-backend zerver/webhooks//
```
Iterate on debugging the test and webhooks handler until it all
works.
* Capture payloads for the other common types of `POST`s 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//doc.md`(required for
getting it merged into Zulip). You can use existing documentation, like
[this one](https://raw.githubusercontent.com/zulip/zulip/main/zerver/webhooks/github/doc.md),
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](incoming-webhooks-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 streams/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](http://www.ultrahook.com/), 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:
```
{{ api_url }}/v1/external/INTEGRATION_NAME?api_key=API_KEY
```
The list of existing webhook integrations can be found by browsing the
[Integrations documentation](/integrations/) 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](/api/api-keys) documentation.
### stream
The stream for the integration to send notifications to. Can be either
the stream ID or the [URL-encoded][url-encoder] stream name. By default
the integration will send direct messages to the bot's owner.
!!! tip ""
A stream ID can be found when [browsing streams][browse-streams]
in the web or desktop apps.
### topic
The topic in the specified stream for the integration to send
notifications to. The topic should also be [URL-encoded][url-encoder].
By default the integration will have a topic configured for stream
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`.
!!! tip ""
For a list of supported events, see a specific [integration's
documentation](/integrations) page.
[browse-streams]: /help/introduction-to-channels#browse-and-subscribe-to-channels
[add-bot]: /help/add-a-bot-or-integration
[url-encoder]: https://www.urlencoder.org/
## Related articles
* [Integrations overview](/api/integrations-overview)
* [Incoming webhook walkthrough](/api/incoming-webhooks-walkthrough)
* [Non-webhook integrations](/api/non-webhook-integrations)