> ## Documentation Index
> Fetch the complete documentation index at: https://docs.lukittu.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Licenses

> Licenses are the cornerstone of the Lukittu system, providing access control to your software. Without a valid license, users cannot access your software. License keys enable you to track software usage and prevent unauthorized access.

## License Properties

When creating a license in Lukittu, you can configure the following properties:

### License Key Format

License keys follow the format `XXXXX-XXXXX-XXXXX-XXXXX-XXXXX`, where X can be any character from A-Z or 0-9. Keys are unique within each team. You can either:

* Generate the key automatically through Lukittu
* Manually specify a custom key

### Expiration Types

#### 1. Never

Suitable for lifetime access products. The license will never expire once issued.

#### 2. Date

Set a specific expiration date for the license. The expiration date is timezone-aware and will be set according to your dashboard's timezone.

<Info>
  Example: Setting an expiration date of 12/12/2022 will make the license
  invalid after that date.
</Info>

#### 3. Duration

Specify a time period after which the license expires. You can choose when the expiration countdown begins:

* **Creation**: Timer starts when the license is created
* **Activation**: Timer starts upon first license activation, generating an expiration date based on the activation date

### Access Limitations

#### IP Limitations

Restrict the number of unique IP addresses that can use the license. Configure the IP limit period in team settings:

* **Day**: Maximum unique IPs per day
* **Week**: Maximum unique IPs per week
* **Month**: Maximum unique IPs per month

#### Concurrent Users

Control how many users can simultaneously use the license. This feature:

* Tracks usage through heartbeat signals
* Uses the "HWID timeout" setting from team settings to determine when a device becomes inactive
* Marks devices as inactive if no heartbeat is received within the timeout period

<Warning>
  **Important**: Dockerized environments may have issues with concurrent user
  limits due to difficulties in generating unique hardware identifiers.
</Warning>

### Assignment Options

#### Product Assignment

Restrict license usage to specific products in your portfolio. This is useful when:

* Managing multiple products
* Creating product-specific licenses
* Implementing tiered access

#### Customer Assignment

Control which customers can use the license:

* Assign multiple customers to a single license
* Enable shared license functionality
* Requires customer ID in authentication requests

### License Status

Licenses can have one of five statuses: ACTIVE, INACTIVE, EXPIRING, EXPIRED, or SUSPENDED. The status is automatically determined based on several factors:

#### Last Active Date

* Tracks when the license was last used
* Initially set to license creation date
* Updates with each license authentication request
* Used to determine inactivity status

#### Status Types

##### 1. ACTIVE

* Default status for valid, recently used licenses
* License is within expiration period
* Has been used within last 30 days

##### 2. INACTIVE

* No license activity for over 30 days
* License is still valid but unused
* Applies to all license types

##### 3. EXPIRING

* License will expire within 30 days
* Only applies to DATE and DURATION type licenses
* License is still valid and usable

##### 4. EXPIRED

* Past the expiration date
* Only applies to DATE and DURATION type licenses
* License is no longer valid

##### 5. SUSPENDED

* Manually suspended by administrator
* Overrides all other status checks
* License is temporarily invalid

<Note>
  A license is considered inactive if there have been no authentication
  requests for over 30 days, regardless of its expiration status.
</Note>

#### Suspension

* Temporarily disable licenses using the suspension feature
* Suspended licenses are considered invalid
* Useful for temporary access restriction

### Metadata

Store additional license information using metadata:

* Custom fields for extra license details
* Used by integrations
* Flexible data storage for specific use cases