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Data flow

Between the JavaScript SDK's UI and the LMS (License Management Server) system, only the following data is transferred:

  • license key
  • license secret
  • usage count (i.e. the number of transactions on the license)

This is the only information that is sent from the client to Wacom.

JS Dataflow

Customer System

Web App

On the web app, users then have the ability to set the license proxy and request a signature capture. These abilities utilize the setLicenseProxy() and generateSignature() functions respectively in order to complete these tasks. Both setLicenseProxy() and generateSignature() interact with the Signature SDK Module.

If the license is valid and upon completion of the signing of a signature, the Signature SDK Module will return SigObj data, readEncodedBitmapBinary() and the signature image to the web app. The signature will then be rendered and displayed by the web app for the user.

Information on if the license is invalid is contained in the section below.

Signature SDK Module and license proxy

After running setLicenseProxy(), validation will be conducted and a proxy set for licensing. The user's license key will then be returned to the module by the proxy.

The module also facilitates retrieval of the license's status by communicating with the LMS/License Management Server.

  • If the license is valid, the Signature SDK Module will present the signature capture UI web app-side to the user. When a user signs and subsequently sends signature data, the SDK Module will send the license key, secret and usage count to the LMS.

  • If the license is invalid - be it expired, out of transactions, not inserted or otherwise - then the Signature SDK Module will return the relevant license error to the web app, where the error will subsequently be displayed to the user.


- A network is required for access to the LMS on the first time using the application. After this, the offline params offlineTime and offlineCount track the maximum allowed period of time and signature quantity allocated to the user when the LMS isn't reachable.

- If the license runs out of transactions and/or time allocated, a new license and a new connection will be required unless the overage param has been specified a value. In this case, the license may be used the number of times more as specified in overage. For example, if overage is set as 10, then the license may be used 10 additional times after the license runs out of transactions. However, users will be charged for additional uses.

Wacom Backend Infrastructure

LMS (License Management Server) and License Database

Once the LMS has received the get license status request, it will load the license info from the license database. The database will then return the usage of the license and its current state. If the license is valid when attempting to sign, the LMS will update license usage information within the license database.