Registration System for your Plugins

SynthEdit includes a set of modules that let you add a basic registration system to a commercial plugin. You issue each customer a serial number tied to their name (or email), the plugin checks that serial on load, and you unlock features — or remove a “demo” limitation — only when a valid serial is present.

This is intentionally a lightweight scheme: it discourages casual copying, not a determined attacker. It needs no internet connection and no licence server.

The modules involved

Module	Category	Role
Registration Serial Generator	Special	Your tool for creating serials. Never ship this to customers.
Registration Check	Special	Lives inside your plugin. Verifies a name + serial and outputs a Is Valid boolean.
User Setting - Text	Sub-Controls	Stores a piece of text (the name, the serial) on disk so it survives a restart.

The Registration Check module has these pins:

• Rego Name — the registered user’s name.
• Serial — the serial number to check.
• Random Seed — a whole number unique to your product (see below).
• Is Valid (output) — true only when the serial matches the name for that seed.

The Registration Serial Generator has the matching Rego Name, Random Seed, and a Serial (output) pin that produces the correct serial for that name + seed.

How it works

1. The plugin reads the saved name and serial from two User Setting - Text modules.
2. It feeds them into a Registration Check module along with your secret Random Seed.
3. If Is Valid is true, you enable the full plugin (e.g. drive an LED indicator, bypass a noise/mute, or unlock a feature). If not, the plugin runs in demo mode.

Because the serial is derived from the name and the seed, the same name always produces the same serial — so you can re-issue a customer’s serial at any time just by running the generator again.

Storing the name and serial

Use two User Setting - Text modules — one for the name, one for the serial. Each has:

• Product — a name unique to your plugin (e.g. Acme SuperSynth). This decides which file on disk the value is saved in.
• Key — identifies the setting within that file, e.g. Registration Name and Serial.
• Default — the value used before the user has entered anything.
• value in — connect this to your text-entry control so the user can type their details.
• Value (output) — the saved value, read back on the next load.

The settings are written to a small XML file:

• Windows: C:\Users\<UserName>\AppData\Local\<Product>\Preferences.xml
• macOS: ~/Library/Preferences/<Product>/Preferences.xml

Use a unique Product name and a unique Random Seed

Give every product its own Product name and its own Random Seed. If two plugins share a seed, a serial issued for one will also unlock the other. If they share a Product name, their settings collide in the same file.

Setting it up

1. Add two User Setting - Text modules — set their Product to your plugin’s unique name, and their Key to Registration Name and Serial respectively.
2. Add a text-entry (or similar) control on your panel for each, feeding the value in pins, so customers can paste in the name and serial you send them.
3. Add a Registration Check module. Wire the two saved Value outputs into its Rego Name and Serial pins, and set its Random Seed to your secret number.
4. Use the Is Valid output to gate your plugin — light an LED, un-mute the audio, enable a feature, etc.

Issuing a serial to a customer

1. In a separate SynthEdit project (one you keep private), drop in a Registration Serial Generator.
2. Set its Random Seed to the same number you used in the Registration Check.
3. Type the customer’s name into Rego Name.
4. Read the Serial output and send that name + serial to the customer.

Serials are generated one at a time, by hand — there is no batch/automatic issuing built in.

A note on sandboxed DAWs (macOS)

On macOS, many hosts run plugins inside a sandbox — a security feature that gives the plugin its own private, walled-off storage area instead of the user’s real home folder. Logic Pro, GarageBand, and all AUv3 (Audio Unit v3) plugins are sandboxed; most other DAWs (Reaper, Live, Cubase, Bitwig, Studio One…) are not.

The practical consequence for registration: a sandboxed host keeps its own private copy of the settings file, separate per host. So a customer who registers your plugin in one sandboxed app may be asked to register again when they load it in a different app, because the second app can’t see the first one’s saved serial.

This is a platform limitation, not a bug in the modules. If a single machine-wide registration matters to you, the robust options are to store the licence somewhere shared across hosts (written by your installer, or in the macOS Keychain) rather than relying on per-host settings — or to simply accept that the user registers once per host. On Windows, and in non-sandboxed macOS DAWs, the saved registration is shared normally and this does not arise.

Limitations

• It’s a deterrent, not strong copy protection — the check happens entirely on the user’s machine.
• Serials are issued manually, one per customer.
• On sandboxed macOS hosts the registration is per-host (see above).