How to add another regulatory node and add some functionality to it in corda DLT?

Question

I would like to add a new Notary/Regulatory node in my Cordapp application , which should perform some extra validation checks when transaction is completed between two parties. so that notary/regulatory will be finally checks for some things and stamp the transaction.

Answer 1

There are two options here:

1. Instead of using the default FinalityFlow to notarise, broadcast and record transactions, you can implement your own flow that performs some additional validation before the notarisation step. The limitation here is that the checks are not part of the notary service.

2. Create your own custom notary. Here, the custom validation checks happen within the notary service. The ability to do this is a recent change to the codebase, as such the documentation has not been updated to reflect the changes, however the source docs can be found on github:

   • Instructions for creating a custom notary service: https://github.com/corda/corda/blob/9e563f9b98b79a308d68ecb01c80ce61df048310/docs/source/tutorial-custom-notary.rst
   • Sample custom notary service code: https://github.com/corda/corda/blob/9e563f9b98b79a308d68ecb01c80ce61df048310/docs/source/example-code/src/main/kotlin/net/corda/docs/CustomNotaryTutorial.kt

Answer 2

As Roger notes, you could customise FinalityFlow/implement your own notary.

An alternative would be:

• Add a new node to the network representing some regulator
• Write the contract rules so that the regulator is a required signer on transactions
• Have the regulator do additional checking of the transaction in their flow before signing