Add a custom linkifier

Linkifiers make it easy to refer to issues or tickets in third party issue trackers, like GitHub, Salesforce, Zendesk, and others. For instance, you can add a linkifier that automatically turns #2468 into a link to https://github.com/zulip/zulip/issues/2468.

If the pattern appears in a topic, Zulip adds an Open () button to the right of the topic in the message recipient bar that links to the appropriate URL.

If you have any trouble creating the linkifiers you want, please contact Zulip support with details on what you're trying to do.

Add a custom linkifier

Reorder linkifiers

Linkifiers are processed in order, and will not apply to text that is already linkified. You can therefore choose which linkifiers to prioritize when more than one linkifier applies. See the overlapping patterns section for examples.

Common linkifier patterns

The following examples cover the most common types of linkifiers, with a focus on linkifiers for issues or tickets.

Link to an issue or ticket

This is a pattern that turns a # followed by a number into a link. It is often used to link to issues or tickets in third party issue trackers, like GitHub, Salesforce, Zendesk, and others.

Link to issues or tickets in multiple projects or apps

To set up linkifiers for issues or tickets in multiple projects, consider extending the #2468 format with project-specific variants. For example, the Zulip development community uses #M2468 for an issue in the repository for the Zulip mobile app, #D2468 and issue in the desktop app repository, etc.

Link to issues or tickets in multiple repositories

For organizations that commonly link to multiple GitHub repositories, this linkfier pattern turns org/repo#ID into an issue or pull request link.

Link to a hexadecimal issue or ticket number

The following pattern linkfies a string of hexadecimal digits between 7 and 40 characters long, such as a Git commit ID.

Advanced linkifier patterns

Linkifiers are a flexible system that can be used to construct rules for a wide variety of situations. Linkifier patterns are regular expressions, using the re2 regular expression engine.

Linkifiers use RFC 6570 compliant URL templates to describe how links should be generated. These templates support several expression types. The default expression type ({var}) will URL-encode special characters like / and &; this behavior is desired for the vast majority of linkifiers. Fancier URL template expression types can allow you to get the exact behavior you want in corner cases like optional URL query parameters. For example:

• Use {+var} when you want URL delimiter characters to not be URL-encoded.
• Use {?var} and {&var} for variables in URL query parameters.
• Use {#var} when generating # fragments in URLs.

The URL template specification has brief examples and detailed examples explaining the precise behavior of URL templates.

Linking to documentation pages

This example pattern is a shorthand for linking to pages on Zulip's ReadTheDocs site.

Linking to Google search results

This example pattern allows linking to Google searches.

Overlapping patterns

In this example, a general linkifier is configured to make GitHub repository references like zulip-desktop#123 link to issues in that repository within the zulip GitHub organization. A more specific linkifier overrides that linkifier for a specific repository of interest (django/django) that is in a different organization.