# MobiusFlow Uniform Resource Identifiers (URIs)

Within a MobiusFlow system all hubs, services, objects and resources are identified by a unique address known as a Uniform Resource Identifier or **URI**. These URIs are hierarchical so given the URI for a Mobius resource it is possible to identify which object the resource belongs to, what the object type is, which service the object belongs to and which Mobius node the service is running on.

## Mobius URI Definition <a href="#mobiusflowuniformresourceidentifiers-mobiusuridefinition" id="mobiusflowuniformresourceidentifiers-mobiusuridefinition"></a>

An object’s URI (or name) is defined in 4 parts, namely the hub ID *(<mark style="color:blue;">**HID**</mark>)*, service ID *(<mark style="color:green;">**SID**</mark>)*, object profile ID *(<mark style="color:purple;">**PID**</mark>)* and instance number *(<mark style="color:yellow;">**INS**</mark>)*. A fifth part is added when accessing a specific resource, the resource ID *(<mark style="color:red;">**RID**</mark>)*.

Each part of an object’s URI is a [hexadecimal](https://en.wikipedia.org/wiki/Hexadecimal) uppercase string of a defined length (as shown in the table below). The URI’s parts are separated with a forward slash (/).

A full URI is typically defined as <mark style="color:blue;">**HID**</mark>**/**<mark style="color:green;">**SID**</mark>**/**<mark style="color:purple;">**PID**</mark>**/**<mark style="color:yellow;">**INS**</mark>**/**<mark style="color:red;">**RID**</mark>.

It is possible to address any part of the system by only using the required parts of the URI. e.g. to address a service only the first two parts of the URI are used <mark style="color:blue;">**HID**</mark>**/**<mark style="color:green;">**SID**</mark> and to address an object only the first four parts are used <mark style="color:blue;">**HID**</mark>**/**<mark style="color:green;">**SID**</mark>**/**<mark style="color:purple;">**PID**</mark>**/**<mark style="color:yellow;">**INS**</mark>.

<table data-header-hidden><thead><tr><th width="138"></th><th></th><th></th><th></th></tr></thead><tbody><tr><td><strong>URI Section</strong></td><td><strong>Length</strong></td><td><strong>Example</strong></td><td><strong>Description</strong></td></tr><tr><td><mark style="color:blue;"><strong>HID</strong></mark></td><td>6</td><td>000001</td><td>The Mobius Hub or node ID. This should be unique within a MobiusFlow system.</td></tr><tr><td><mark style="color:green;"><strong>SID</strong></mark></td><td>3</td><td>01F</td><td>The microservice ID. This must be unique for all services on a single node.</td></tr><tr><td><mark style="color:purple;"><strong>PID</strong></mark></td><td>4</td><td>003A</td><td>The object's profile ID. This describes the objects type. Object profiles determine what resources an object has available.</td></tr><tr><td><mark style="color:yellow;"><strong>INS</strong></mark></td><td>4</td><td>0001</td><td>The object's instance number. This is unique for each object of a specific type belonging to a service.</td></tr><tr><td><mark style="color:red;"><strong>RID</strong></mark></td><td>2</td><td>40</td><td>The resource ID</td></tr></tbody></table>

An example of an object URI for an object of instance 1, profile 3A, created by service 1F connected to hub 1 is:

*<mark style="color:blue;">**000001**</mark>**/**<mark style="color:green;">**01F**</mark>**/**<mark style="color:purple;">**003A**</mark>**/**<mark style="color:yellow;">**0001**</mark>*&#x20;

and if addressing resource 40 on that object the full URI would be:

*<mark style="color:blue;">**000001**</mark>**/**<mark style="color:green;">**01F**</mark>**/**<mark style="color:purple;">**003A**</mark>**/**<mark style="color:yellow;">**0001**</mark>**/**<mark style="color:red;">**40**</mark>*

## Mobius URI Wildcards <a href="#mobiusflowuniformresourceidentifiers-mobiusuriwildcards" id="mobiusflowuniformresourceidentifiers-mobiusuriwildcards"></a>

Under certain conditions, such as subscribing to a resource’s change of value event, it is possible to use wildcards in the URI. These wildcards are described in the table below and follow the MQTT standard.

| **Wildcard** | **Meaning**                                             | **Example**                                                                                                                                                                                 |
| ------------ | ------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **+**        | Any value in this location                              | <mark style="color:blue;">000001</mark>/<mark style="color:green;">+</mark>/<mark style="color:purple;">003A</mark>/<mark style="color:yellow;">+</mark>/<mark style="color:red;">40</mark> |
| **#**        | Any value in this location and all subsequent locations | <mark style="color:blue;">000001</mark>/<mark style="color:green;">01F</mark>/<mark style="color:purple;">#</mark>                                                                          |