Below is a well-deserved Q2 update highlighting ecosystem tooling and solutions across April, May, and June.

The past three months have been all about tightening up infrastructure, enhancing developer tools, and shipping valuable updates to support the Cardano ecosystem. With over 90 pull requests merged and 60+ issues closed in June alone, it’s been a highly productive quarter.

Check out the highlights below to see what’s been delivered.

⚙ Cardano Rosetta Java​

cardano-foundation/cardano-rosetta-java

April: 23 PRs merged focused on performance and stability:

• Spring Boot 3.4 + JDK 21 Virtual Threads
• Docker build-from-source support, Ubuntu 24.04
• Sync status upgrades, transaction serialization fixes, and Mithril patching
• Current release: v1.2.7 → v1.2.8 incoming (Mithril fix) → v1.2.9 already in testing

May: Continued evolution of the Cardano Rosetta integration stack coming very soon:

• Upgraded to JDK 24 LTS and Spring Boot 3.4 for modern runtime compatibility
• Docker-based infrastructure improvements — cleaner container splits and environment handling
• Added support for building Postgres, Mithril, and Cardano Node from source in both single-container and Docker Compose setups — a key security feature over pulling pre-built images
• Retry mechanism added for better node submission resilience
• Cleaned up pruning variable usage, enhanced /network/status endpoint with oldest_block
• Closed issues include runtime upgrades, variable cleanup, and improved Docker orchestration for internal deployments

June: 18 PRs Merged | 5 Issues Closed

Wide-ranging fixes and enhancements throughout the Rosetta Java stack:

• Resolved issues with reward withdrawal, DRep vote delegation parsing, and nested token bundles in the /construction/parse endpoint
• Upgraded Docker setups for single-container builds (Cardano Node, Mithril, Postgres)
• Improved environment variable handling, renamed key config fields, and added retry logic
• Closed issues related to pruning behavior, stake balance endpoint responses, and internal release testing for v1.2.9

🔷 Cardano IBC Incubator​

cardano-foundation/cardano-ibc-incubator

May: Mitigated the token dust attack vector uncovered during the security audit

June: 9 PRs Merged | 2 Issues Closed

• Brought down deployment costs to 570 ADA
• Upgraded Mithril and Cardano node version

🔷 Ada Handle Resolver​

cardano-foundation/cf-adahandle-resolver

May: Released v0.1.4 — now using Yaci Store 0.1.2 and Spring Boot 3.3.11

🔗 Connect with Wallet​

cardano-foundation/cardano-connect-with-wallet

April: The wallet list component caught up with the wallet button — now fully supports CIP-45 and mobile wallets. Nice polish!

June: PRs Merged | 1 Issue Closed

• Resolved a release issue where CIP-30 wallets weren't being properly detected — improving compatibility across wallet integrations

💰 Java Rewards Calculation​

cardano-foundation/cf-java-rewards-calculation

April: Bug report opened to improve stake key registration checks at epoch boundaries.

🧰 Cardano Client Lib​

bloxbean/cardano-client-lib

April: Fixed performance issue with dummy signers — now avoids unnecessary account generation.

June: 4 PRs Merged

Precision fixes to improve developer reliability:

• Resolved native script parsing issues caused by indefinite-length arrays
• Migrated repository publishing from OSSRH to the new Maven Central portal

May:

• Fixed a subtle bug in multi-asset value subtraction logic
• Also opened a new issue to catch transaction builder errors when negative balances are likely — improving developer feedback during build time

🧪 Yaci DevKit​

bloxbean/yaci-devkit

April: Open community discussion kicked off on how devs can best use Yaci locally. Great move to engage builders!

May:

• Added fixes for Plutus V3 compatibility with Lucid Evolution
• Improved community-facing tooling: beta builds now pushed with clearer NPM version tags
• Feature request raised for managing public network setups using Yaci CLI

June: 2 PRs Merged | 1 Issue Closed

CLI and testing enhancements:

• Added rollback simulation support using DB snapshots and TCP proxy-based forks in Yaci CLI
• Improved API usability with Swagger annotations
• Closed the issue for passing --era flags via CLI

➗ Yaci​

bloxbean/yaci

April: Resolved JSON serialization issue affecting governance number types. Clean and precise.

June: 4 PRs Merged

Resilience and parsing improvements:

• Improved error handling for N2NChainSyncFetcher, allowing continuation on parse failure
• Fixed native script parsing errors and merged relevant CI and Maven-related changes

🏛 Yaci Store​

bloxbean/yaci-store

April: v2.0.0-beta1 Released — now with full ledger-state calculation! This is huge 🤯:heart_on_fire::up_parrot: No need for DB Sync — Yaci Store independently derives rewards, ADAPot, and governance state from block data.

• Viewers now live for Preview, Preprod, and Mainnet
• Validated up to: epoch 916 (Preview), 212 (Preprod), 545 (Mainnet)
• 28 PRs merged, including:
  • New API endpoints (Proposals, DReps, Rewards, AdaPot, Network Info)
  • Governance fixes (DRep expiry, snapshot handling)
  • Native image support, rollback improvements, docs upgrades

May: One of the most active repositories this month — with 13 PRs merged tackling governance data integrity, rollback logic, and infrastructure improvements

Major upgrades:

• Introduced Content-Aware Rollbacks to calculate data correct
• Improved proposal tracking and refund accuracy in governance modules
• Fixed Byron-era epoch lengths and slot duration mismatches on local devnet
• Switched to JDK 24 for runtime
• Closed a key issue improving governance and adapot module inclusion in yaci-store-all

June: 20 PRs Merged | 6 Issues Closed

Big month for Yaci Store — including the 2.0.0-beta2 pre-release!

• Introduced a powerful plugin framework for granular scope indexing with support for MVEL, SpEL, JS, and Python
• Added Prometheus metrics and initial monitoring dashboard for sync and Adapot status
• Implemented witness saving enable/disable option and epoch stake pruning
• Fixed native script parsing for the Preview network and adjusted stake filtering for inactive DReps
• Closed key issues related to adapot mismatches, Docker runtime configs, datasource cleanup, and governance metadata
• Positioned for broader extensibility and production-readiness with the 2.0.0-beta2 milestone

Thanks you to everyone who contributed throughout Q2. Your dedication, expertise, and energy are driving real progress across the ecosystem!​

Monthly changelogs can be below:

• April
• May
• June

In this interview, Kristian Portz, co-founder of Masumi Network, explains how the platform builds infrastructure for AI agents to work together, make decisions, and handle payments autonomously - while staying secure and compliant with European regulations. Built on the Cardano blockchain, Masumi creates transparent systems where agents interact without human input. Portz highlights real-world use cases in finance and healthcare and considers how AI agents might shape future governance, marking a shift in technology collaboration. Sounds Exciting? Well..let’s dive right in!

In this session of the Cardano Developer Office Hours, the team presents PoP (Proof of Provenance), a project to decentralize open-source development on Cardano. They cover risks of centralized infrastructure, using Cardano for verifiable software metadata, Merkle trees, and on-chain tracking. A live demo shows PoP in action. Use cases include secure versioning, on-chain test management, SPOs as decentralized oracles, and decentralized package tools.

Alex Nemish and Oleksii Khodakivskyi from Lantr introduce Scalus, a smart contract framework built with Scala 3. They walk through the vision, roadmap, and show how it simplifies development on Cardano, including a live demo of a payment splitter contract. This session is ideal for devs exploring new tools to build on Cardano.

In this interview, Rusty, also known as fallen-icarus on X, shares his vision for a truly decentralized financial system. He discusses the flaws in today’s DeFi models, which often rely on centralized mechanisms, and explains why a shift to P2P DeFi is necessary. Rusty breaks down key concepts like liquidity sharing, UTXO contention, and free-market solutions, offering a fresh perspective on making DeFi more scalable, efficient, and accessible. To learn more about the P2P DeFi solution Rusty proposes, check out the full interview below.

Giovanni Gargiulo, Senior Software Engineer at the Cardano Foundation, shares how ecosystem engineering supports Cardano’s growth. The session covers DevOps practices behind scalability, security, and uptime, along with challenges of running decentralized infrastructure. Giovanni also touches on infrastructure evolution, global adoption, and what’s ahead for Cardano engineering.

Satya Ranjan, Lead Blockchain Architect at the Cardano Foundation, presents Java tools for building on Cardano. The session covers cardano-client-lib, writing off-chain code, building transactions, and integrating governance and staking. Satya also demos Yaci DevKit for local dev environments, Yaci Store for indexing, and shows how to build lightweight apps using tailored data. Ideal for developers and exchanges exploring Java’s role in Cardano infrastructure.

This installment of the Cardano Developer Office Hours explores Reeve, a next-generation accountability tool for delivering tamper-proof and transparent financial insights. Reeve integrates traditional accounting systems with blockchain technology, ensuring transparency, immutability, and security for financial records. Built on Cardano, the platform offers a decentralized approach to financial data management. Designed for accountants, auditors, non-profits, and enterprises, Reeve helps streamline audits, improve efficiency, and build trust in financial processes. The session provides an overview of the project, its architecture, and current development.

This installment of the Cardano Developer Office Hours explores the Cosmos-Cardano Inter-Blockchain Communication (IBC) bridge project. The session provides an overview of the architecture, current development, and key components driving the project. Topics include the IBC protocol, blockchain interoperability, and the integration of Cosmos SDK with Cardano. A live demo showcases how to send messages between the Cosmos network and a local Cardano node. The session also covers real-world use cases like token transfers, cross-chain swaps, and more.

This 13th installment of the Cardano Developer Office Hours is presented by Thomas Kammerlocher, Senior Full Stack Developer at the Cardano Foundation. Thomas discusses the Java implementation of Rosetta, a tool developed by Coinbase for exchanges to integrate with Cardano. Rosetta simplifies multi-chain support with its blockchain-agnostic API, and the transition from TypeScript to Java enhances performance and reduces resource consumption. Upcoming updates include support for staking rewards tracking, off-chain data integration, and more improvements to scalability and efficiency.