:orphan:

URI Format
==========

WAMP uses URIs (*Uniform Resource Identifiers*) to identify topics,
registered procedures, and errors. All of these form a single, global,
hierarchical namespace.

To avoid resource naming conflicts, WAMP follows the package naming
convention from Java, where URIs should begin with (reversed) domain
names owned by the organization defining the URI.

So for a company using the domain "expressweasel.com" an URL for a login
procedure could be

::

    com.expressweasel.user.login

URI format rules
----------------

Crossbar.io implements the strict URI conventions from the WAMP
specification. This is in order to assure that URIs are valid
identifiers across as many languages as possible.

This means:

-  Allowed characters are **lower case** letters, numbers, '.' and '\_'.
   (Lower case letters are used to ensure compatibility with languages
   which have case-insensitive identifiers.)
-  There can be no non-empty parts between the separating full-stops,
   e.g. ``com.expressweasel.user..start`` is not a valid URI. (It could
   be used as part of patter-based subscriptions/registrations though.)
-  ``wamp`` as an inital URI part is not allowed, since this is reserved
   for URIs predefined with the WAMP protocol itself.
-  ``crossbar`` as an initial URI part is not allowed, since this is
   used by Crossbar.io itself for internal messaging.