License Management

This page describes how to manage your QUBO++ license using the qbpp-license command-line utility. The license system is shared between QUBO++ (C++) and PyQBPP (Python).

License Types

QUBO++ offers several license types with different variable count limits and validity periods.

License Type	Key Required	Validity	CPU Variables	GPU Variables
Anonymous Trial	No	7 days	1,000	1,000
Registered Trial	Yes	30 days	10,000	10,000
Standard	Yes	Agreement term	2,147,483,647	1,000
Professional	Yes	Agreement term	2,147,483,647	2,147,483,647
Fallback	N/A	Always	100	100

Anonymous Trial: No registration required. Automatically activated on first use.
Registered Trial: Requires a free license key for evaluation purposes. Apply here.
Standard License: For production use. Supports large-scale CPU optimization.
Professional License: For production use with GPU acceleration (ABS3 Solver, Exhaustive Solver).
Fallback Mode: When no valid license is found or the license has expired, QUBO++ runs with a 100-variable limit.

Setting and Activating the License Key

If you have a license key, set it using one of the following methods.

Method 1: Activate with `qbpp-license` (recommended)

Run the following command once per machine:

qbpp-license -k XXXXXX-XXXXXX-XXXXXX-XXXXXX -a

The license key is encrypted and cached locally. After activation, no environment variable or -k option is needed for subsequent runs — QUBO++ programs automatically use the cached key.

To re-activate or change the key, simply run the command again with a new key.

Method 2: Environment Variable

Set the QBPP_LICENSE_KEY environment variable. This is useful for Docker/CI environments where the local cache is not persistent.

export QBPP_LICENSE_KEY=XXXXXX-XXXXXX-XXXXXX-XXXXXX

Priority

When multiple methods are used, the following priority applies:

-k argument or qbpp::license_key() in code (highest)
QBPP_LICENSE_KEY environment variable
Cached key (lowest)

Note: For Anonymous Trial, no license key is needed. Simply run qbpp-license -a without setting a key.

Checking License Status

To display the current license status without making any changes:

qbpp-license

This shows the license type, expiry date, variable limits, and activation usage. The command contacts the license server to refresh the status.

Deactivating a License

To move a license to another machine, first deactivate it on the current machine:

qbpp-license -d

Each license key has a limited number of allowed activations.
Deactivation frees up one activation slot.
Anonymous Trial licenses cannot be deactivated.
There is a 24-hour cooldown between consecutive deactivations to prevent abuse.

Command Reference

Usage: qbpp-license [options]

Options:
  -h, --help         Show help message and exit
  -k, --key KEY      Specify a license key
  -a, --activate     Activate the license on this machine
  -d, --deactivate   Deactivate the license on this machine
  -t, --time-out SEC Set the server communication timeout (default: 20 seconds)

Examples

Command	Description
`qbpp-license`	Display current license status
`qbpp-license -a`	Activate (Anonymous Trial if no key is set)
`qbpp-license -k KEY -a`	Activate with a specific key
`qbpp-license -d`	Deactivate the license on this machine
`qbpp-license -t 60`	Check status with a 60-second timeout
`qbpp-license -k KEY -t 60 -a`	Activate with a key and extended timeout

How License Verification Works

qbpp-license command: Always contacts the license server to get the latest status. This may take a few seconds depending on network conditions.
QUBO++ programs: Verify the license using the local cache and do not block on server communication. The server is contacted only when the cache needs to be refreshed (e.g., after a long period without synchronization).
License key storage: When a license is activated, the key is encrypted and cached locally. This allows subsequent runs without setting the key again.

Network and Timeout

If your network is slow or behind a firewall/proxy, the default 20-second timeout may not be enough.

To increase the timeout:

qbpp-license -t 60 -a

If the server is unreachable, QUBO++ falls back to the cached license status. If no cache exists, QUBO++ runs in Fallback Mode (100-variable limit).

Programs work but with limited variables

QUBO++ may be running in Fallback Mode. Check the license status:
```
$ qbpp-license
```
Ensure the license key is set correctly via qbpp-license -k KEY -a or QBPP_LICENSE_KEY.
Re-activate if necessary: qbpp-license -a

“Deactivation cooldown”

There is a 24-hour waiting period between consecutive deactivations.
Wait and try again after the cooldown period has elapsed.

Floating Licenses

Floating licenses allow shared access across multiple machines within an organization. Instead of being permanently locked to a machine, a floating license uses a lease-based mechanism.

When a QUBO++ program starts, it acquires a lease from the license server.
The lease is automatically renewed while the program is running.
When the program exits, the lease is released, making the slot available for other machines.
If the program crashes or the network is lost, the lease expires automatically after a timeout period.

Usage is the same as node-locked licenses:

qbpp-license -k F-XXXXXX-XXXXXX-XXXXXX-XXXXXX -a

The floating license key is also cached locally, so subsequent runs do not require setting the key again.