Interwiki Links

Interwiki links are a short-hand notation for links that target external wikis or websites. For example, the following two hyperlinks mean the same thing (assuming an appropriate intermap configuration):

Another example: The Fossil Forum is hosted in a separate repository from the Fossil source code. This page is part of the source code repository. Interwiki links can be used to more easily refer to the forum repository:

Advantages Over Full URL Targets


Fossil supports interwiki links in both the Fossil Wiki and Markdown markup styles. An interwiki link consists of a tag followed by a colon and the link target:


The Tag must consist of ASCII alphanumeric characters only - no punctuation or whitespace or characters greater than U+007A. The PageName is the link notation on the target wiki. Three different classes of PageNames are recognized by Fossil:

  1. Path Links → the PageName begins with the "/" character or is an empty string.

  2. Hash Links → the PageName is a hexadecimal number with at least four digits.

  3. Wiki Links → An PageName that is not a Path or Hash.

The Intermap defines a base URL for each Tag. Path links are appended directly to the URL contained in the Intermap. The Intermap can define additional text to put in between the base URL and the PageName for Hash and Wiki links, respectively.


The intermap defines a mapping from interwiki Tags to full URLs. The Intermap can be viewed and managed using the fossil interwiki command or the /intermap webpages.

The current intermap for a server is seen on the /intermap page (which is read-only for non-Setup users) and at the bottom of the built-in Fossil Wiki rules and Markdown rules documentation pages.

Each intermap entry stores, at a minimum, the base URL for the remote wiki. The intermap entry might also store additional path text that is used for Hash and Wiki links. If only the base URL is provided, then the intermap will only allow Path style interwiki links. The Hash and Wiki style interwiki links are only allowed if the necessary extensions for provided in the intermap.

Disadvantages and Limitations

Intermap Storage Details

The intermap is stored in the CONFIG table of the repository database, in entries with names of the form "interwiki:Tag". The value for each such entry is a JSON string that defines the base URL and extensions for Hash and Wiki links.

See Also