Hydra Integration for Kuber
Repository: https://github.com/dquadrant/kuber
Summary
This project integrates Kuber, a Haskell-based Cardano Layer 1 transaction builder, with Hydra, Cardano’s Layer 2 scalability solution. Kuber simplifies transaction construction by allowing developers to define transactions in JSON, abstracting away complex tasks like fee balancing and submission. The goal is to extend this user-friendly transaction interface to also support the Hydra protocol, enabling developers to submit Layer 2 transactions just as easily as Layer 1.
Kuber already supports full functionality for Layer 1, including transaction construction, validation, and submission. This integration will bring the same functionality to Hydra, allowing developers to interact with a Hydra Head as easily as with Layer 1.
Scope of Project
- Extend Kuber to support building, validating, and submitting transactions over a Hydra Head.
- Implement Hydra lifecycle operations via Kuber API, including initializing the head, committing UTxOs, closing, aborting, and fanout.
- Provide well-structured WebSocket proxy support to receive and interpret Hydra events.
- Ensure Kuber works seamlessly with both mainnet and testnet deployments.
- Provide a client library to easily integrate with the backend
Milestones
M1 Project Planning and Architecture
Deliverables
- Deliverable includes this document and project architecture details
- Details are published to github : Architecture.md
M2.1 - Core Hydra Functionalities (Haskell, kuber-server)
Deliverables
- 2.1.1 Hydra WebSocket Integration – Kuber connects to and parses Hydra WebSocket event stream
- 2.1.2 Hydra Lifecycle Relay API – Endpoints for init, commit, decommit, close, contest, abort, fanout
- 2.1.3 Query API Implementation – REST APIs for querying UTXOs, state, protocol parameters
- 2.1.4 Transaction Build Support – JSON-based builder adjusted for Hydra; validation and balancing
- 2.1.5 Finalization & Documentation – Markdown docs, GitHub issues, testing, demo setup
M2.2 - Browser/Nodejs suppport (kuber-client)
Features
- Implementation of Hydra functionalities in JavaScript for the npm package.
- Ability to listen and react to events/transactions on hydra node.
- Submit transactions to hydra node and get transaction status.
- Compatibility with DApps, including wallet connection for transaction signing.
- Extensive test coverage for the npm package.
Deliverables
2.2.1 Verification of compatibility with existing Kuber/Hydra APIs. 2.2.2 Client Package - Published npm package and test results in the repository.
M3: Documentation and Community Engagement
Todos
- Comprehensive documentation for the Hydra-enabled Kuber library, Kuber Playground, and Kuber-Client npm package.
- Tutorials and guides for developers to integrate Hydra features into their applications. a
Deliverables
- Docusaurus deploymennt with docs and tutorials.
Risks and Issues
- Hydra WebSocket Latency:
- Submissions and state transitions may have slow response times.
- Non-standard API Responses:
- Some requests (e.g., transaction submission) may result in a
201 Createdinstead of200 OK, due to asynchronous handling.
- Some requests (e.g., transaction submission) may result in a
- Hydra Node Setup:
- Kuber does not manage or deploy Hydra nodes; users must set them up and configure connectivity manually.
🗓️ Hydra Integration Project Timeline
| Phase | Milestone/Task | Estimated Duration | Start Date | End Date | Deliverables |
|---|---|---|---|---|---|
| 🔹 M1 | Project Planning & Architecture | 2 weeks | March 1 | March 15 | Architecture document, GitHub setup |
| 🔹 M2.1.1 | Hydra WebSocket Integration | 1.5 weeks | April 6 | April 18 | Hydra WS connection, event parsing |
| 🔹 M2.1.2 | Lifecycle Relay API Endpoints | 1 week | March 16 | March 22 | API: init, commit, close, abort, fanout |
| 🔹 M2.1.3 | Query API Implementation | 1 week | March 23 | March 29 | REST APIs for UTXO, state, protocol params |
| 🔹 M2.1.4 | Hydra Transaction Build Support | 3 weeks | April 19 | May 10 | JSON builder, validation, balancing |
| 🔹 M2.1.5 | Finalization & Documentation | 1 week | May 11 | May 17 | Markdown docs, issue tracking, test/demo |
| 🔹 M2.2.1 | Client-side Hydra Support (npm package) | 3 weeks | May 18 | June 6 | JS package: listen, submit, test, publish |
| 🔹 M2.2.2 | Package Publication | 1 week | June 7 | June 13 | Verified build, published to npm |
| 🔹 M4 | Documentation & Community Engagement | 2 weeks | June 14 | June 27 | Docusaurus deployment, tutorials, examples |