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· 2 min read
Marcin Szamotulski

Overview of spint 102

Leios

We completed a basic prototype of a request-respond mini-protocol that supports server-side message reordering while ensuring both deadlock and livelock freedom. The prototype was reviewed by the consensus and formal methods teams. Next development steps involve simplifying the API and evaluating specific modifications tailored for Leios. At this point, we consider the technical risk of this development direction to be addressed and are transitioning to other, higher-priority Leios tasks.

Mithril

We're moving the development to a new repository: https://github.com/IntersectMBO/dmq-node

Ouroboros Network

Cardano Node

· 2 min read
John Lotoski

High level summary

The SRE team continues work on Cardano environment improvements and general maintenance.

Some notable recent changes, updates or improvements include:

  • Within approximately 1 day of the preview network partition occurring, mentioned in the last biweekly SRE update, mainnet experienced a similar partition. Again, after an intense multi-team and community collaborative effort which the SRE team was participating in from the beginning, a new cardano-node version 10.5.3 was released to fix the issue, with all network participants on problematic versions encouraged to upgrade immediately so that the partition would resolve itself as the majority of stake aligned under node versions with proper ledger hash handling. Indeed, with the quick reaction of the community as a whole, the network partition resolved within approximately 14 hours. Various after action reports are available detailing the event, such as Pi Lanningham's Poison Piggy - After Action Report

  • Subsequent to the mainnet fork event above, 10.6.1 has also been pre-released and deployed to IOE pre-release infrastructure. The SRE team has also been participating in other after action investigation activity.

Repository Work -- Merged

Cardano-mainnet

  • Bumps and deploys cardano-node release to 10.5.3

  • Fixed Mithril scripts due to Mithril aggregator upstream API breaking changes

  • Updates the save-ssh-config recipe to match opentofu ssh config artifact output

  • Cleaned up flake.nix inputs and some colmena modules code

  • Modifies two bootstrap EBS gp3 volumes to accommodate some data handling work

    cardano-mainnet-pr-40

Cardano-parts

  • Bumps cardano-node release to 10.5.3, pre-release to 10.6.1, and cardano-db-sync pre-release to 13.6.0.6

  • Mithril script code for node entrypoint, systemd ExecPre and process-compose jobs were fixed to accommodate breaking upstream API changes

  • The pkgs.nix flakeModule was re-factored to make switching between localFlake and capkgs pins easier

    cardano-parts-release-v2025-12-04

Cardano-playground

  • Bumps and deploys cardano-node release to 10.5.3, pre-release to 10.6.1, and cardano-db-sync pre-release to 13.6.0.6

  • Updates the cardano-book for the corresponding cardano-node release and pre-release updates

  • Adds a metrics scraper nixosModule for perf team custom data analysis

  • Fixed Mithril scripts due to Mithril aggregator upstream API breaking changes (via cardano-parts pin update)

  • Updates the save-ssh-config recipe to match opentofu ssh config artifact output

  • Cleaned up flake.nix inputs and some colmena modules code

    cardano-playground-pr-52

Repository Work In Progress -- PRs and Branches

· One min read
Noon van der Silk

What did the team achieve?

  • Implemented the "SafeClose" feature #2330
  • Continued working on partial fanout #1468
  • Continued working on chain following approach #2206
  • Organised a lovely team off-site!
  • Worked on running hydra-node on a Rasberry PI #2353
  • Added API to retrieve head start timestamp #2316
  • Added blockfrost support to the TUI #2032
  • Released version 1.2.0!

What's next?

  • Finish Rasberry PI demo #2353
  • Continue working on partial fanout #1468
  • Continue work on chain-following improvements #2206
  • Tighten up documentation around contestation period #2389
  • Add a few more test cases to our HTLC demo

· 2 min read
Alexey Kuleshevich

High level summary

This period Ledger team completed full definion in Haskell and binary representation with CDDL specification of what it means to be a Nested Transaction. Besides this important milestone we've tackled some tech dept, added ability to inject a Cost Model for any Plutus version upon startup for the purpose of testing and benchmarking, optimized memory accounts representation and improved usability of some predicate failures. We made some very nice progress on enhancing CDDL specification with cuddle, which will allow us to reduce quite a bit of code duplication and improve CDDL conformance property testing.

Low level summary

Features

  • PR-5419 - Type-class-based CDDL generation
  • PR-5413 - Subtransactions CBOR deserializer
  • PR-5379 - Add ability to inject any cost models via AlonzoGenesis
  • PR-5416 - Switch to Credential Staking from RewardAccount in StakePoolState
  • PR-5449 - Improve memory representation of ConwayAccountState
  • PR-5442 - Deprecate StakeCredential and PaymentCredential synonyms
  • PR-5429 - Fail PlutusV4 TxInfo translation when Ptr is present in the TxOuts
  • PR-5455 - Make IncompleteWithdrawals more informative
  • PR-5457 - Required top level guards
  • PR-5441 - Redefine predicate failures in Dijkstra without using CBOR group encoding
  • PR-5450 - Remove set-algebra library and all its usage
  • PR-5443 - CDDL with typeclasses: mary, alonzo, babbage
  • PR-5460 - Ensure EraBlockBody instances are not orphans.
  • PR-5451 - Switch to CompactForm Coin in PParams
  • PR-5383 - Remove listLenBound from EncCBORGroup class

Testing

  • PR-5426 - Test "accepted" predicates in conformance
  • PR-5434 - Add Imp test reproducer for #5418
  • PR-5433 - Make ticking a bit more realistic in Imp tests
  • PR-5440 - Bump constrained-generators

Infrastructure and releasing

· 2 min read
Jean-Philippe Raynaud

High level overview

This week, the Mithril team kept focusing on the SNARK-friendly STM library, completing the Schnorr signature scheme and modules reorganization, and implementing some wrappers for the Jubjub backend. They also progressed on specifying the non-recursive SNARK circuit, assessing constraints on Halo2 verification keys, prototyping the recursive SNARK solution, and prototyping the Bitcoin DeFi prover with RISC Zero.

Additionally, they continued implementing a simple aggregator discovery mechanism, worked on improvements to the protocol security page, and completed enhancements to the end-to-end tests to better support the introduction of new features and improve the reliability of the backward-compatibility test.

Finally, they worked on the second phase of the common aggregator client implementation and kept upgrading to Cardano node v.10.6.

Low level overview

Features

  • Completed the issue Implement Schnorr signature scheme in STM #2756
  • Completed the issue Re-organize modules of STM library #2793
  • Worked on the issue Implement a simple aggregator discovery mechanism #2726
  • Worked on the issue Experimental blst-Jubjub #2772
  • Worked on the issue Compute the IVC state with SHA256 in the recursive circuit #2806
  • Worked on the issue Document recursive SNARK solution #2767
  • Worked on the issue Prepare specifications for the Mithril circuit #2797
  • Worked on the issue Implement Jubjub/Poseidon backends wrappers in Schnorr signature scheme #2817
  • Worked on the issue Assess constraints on Halo2 circuit verification #2799
  • Worked on the issue Feasibility of Bitcoin Defi usecase #2818
  • Worked on the issue Update protocol parameters to SNARK friendly values #2813
  • Worked on the issue Proposals for Mithril/DMQ as optout feature of Cardano #2831

Protocol maintenance

  • Completed the issue Certification stopped on mainnet and preview network #2805
  • Completed the issue Enhance e2e test to support the introduction of new features #2781
  • Completed the issue Enhance reliability of backward compatibility test #2760
  • Completed the issue Stabilize Cardano DB v2 client CLI/library - Phase 4 #2758
  • Completed the issue Revise expiration delays for signed entity types #2826
  • Worked on the issue Enhance protocol security page on website #2703
  • Worked on the issue Upgrade to Cardano 10.6 #2790
  • Worked on the issue Implement a common aggregator client - Phase 2 #2827