Project Scope

The process of integrating the Cactus and Weaver modules and workflows to create a common Cacti platform conforming to the architecture illustrated in the Cacti Roadmap (and below) must follow a particular sequence of steps in order to ensure backward compatibility and avoid breaking preexisting user dependencies on exported Cacti packages and images.

As described in the project proposal, the first step we have identified in the integration process is the building of a Core Operators module (let's call it COPM) that directly acts on a network's (or system's) ledger, which can be seen at the right end of the above diagram. (Note: because different ledgers are built on different DLTs, Cacti will support an extensible suite of COPMs, one for each DLT.)

In this project, we need to do the following:

• Design a generic structure and interface (API) for the COPM that is portable across DLTs (while being implemented in DLT-specific ways for each ledger type.)
  
• Identify a list of Core Operator primitives to implement. Thus far, we have identified a limited set of such operators, which in some combinations can fulfil the three canonical DLT interoperability use cases: data sharing, asset exchange, and asset transfer. (Note: this set is meant to be extensible, to accommodate more operators if we discover functions that are not covered by the below list)
  • lockAsset
  • pledgeAsset
  • claimAsset
  • generateProof
  • verifyProof
  • accessControl
  • noop (this is a passthrough option, for Cacti modules and connectors that do not need to invoke any of the above operators)
• Implement a COPM for Hyperledger Fabric
  • On a best effort basis, implement a COPM (in part or whole) for Corda
  • On a best effort basis, implement a COPM (in part or whole)  for Besu/Ethereum
• Sketch out a template for porting to arbitrary DLTs and write documentation (this may end up being part of the Cacti whitepaper)
• Write scripts to deploy COPMs on a given network
• Refactor existing Cacti packages (select a few) to invoke the appropriate COPM
• Pick some end-to-end examples to showcase (this should cover existing Cactus examples, existing Weaver examples on data sharing, asset exchange, and asset transfer)

Preliminary work:

• Test and evaluate Cactus setups and examples using instructions in the documentation.
  
• Test and evaluate Weaver setups and samples using instructions in the documentation.
  
• Document bugs, required upgrades in software, instruction typos, and identify automation scripts that can help make tooling and CI more efficient.
  
• Expose Weaver modules and libraries through symlinks in the packages  folder to simplify the integration process.

(The intention of this project is to unify multiple interoperability frameworks by creating a reusable set of operators so that the existing frameworks can be migrated to them.)

Key Deliverables

• Cacti Core Operators Module (COPM) design: functions (see the list in the project scope above) and API

  • API should be RESTful, built on gRPC or socket.IO, designed to be integrated with the Cacti Client API and invoked by Cacti Connectors

• Implementation of COPM:

  • Hyperledger Fabric: (required: all functions and API)
  • R3 Corda: (best effort: some functions and associated API)
  • Hyperledger Besu: (best effort: some functions and associated API)
• Selection of use cases (examples) for end-to-end testing: both Cactus (Node Server) and Weaver (Relay) modes
  • Weaver data sharing using test networks (minimum required)
  • Other Weaver use cases (asset exchange, asset transfer) (best effort)
  • Cactus examples: TBD
• CI-automated testing of COPM for all combinations

• Documentation:

  • Updates to architecture, vision, design methodology (as required)

  • Tutorials for running with Cacti samples

  • FAQs (best effort) 

  • Suggestive instructions for adaptation to users' scenarios (best effort)
    

• Updated RFCs: COPM design and API specifications
  

Optional Deliverables

• Unified Cacti CI GitHub workflows
• Dockerize Weaver test tooling for easy setup (equivalent of a the fabric-tools container offered by Fabric)
• Cactus REST APIs updated to use core operators
• Redundant code identified and removed
• Implementation of Core Operator Module in DLTs other than Fabric, Corda, and Besu

Timeline