High level overview​

This week, the Mithril team completed the implementation of the Relation trait for the IVC circuit and the removal of the HTTP client and TLS features from STM. They continued implementing the circuit verification key whitelist/revoke mechanism, supporting an IVC follower aggregator joining the network at any time, and adding a Proof of Bound Possession for the SNARK verification keys. They also started activating the dual genesis keys and the future_snark feature by default, testing the scaling of the SNARK infrastructure to full security parameters, and finalizing the Mithril SNARK Book.

The team completed the certificate chain cache committed after chain verification in the client library and started leveraging it with the EarlyStopVerification mode.

Finally, they released the new 2630.1-hotfix distribution which fixes a stack overflow in the aggregator and signer on the release-preprod network when decoding a block, kept upgrading to Cardano node 11.1, and kept investigating the blocks and transactions verification failure on the testing-preview network.

Low level overview​

Features​

• Completed the issue Implement Relation trait for the IVC circuit #3428
• Completed the issue Remove the HTTP client and TLS features from STM #3558
• Completed the issue Add a certificate chain cache committed after chain verification in the client library #3520
• Worked on the issue Implement circuit verification key whitelist/revoke mechanism #3148
• Worked on the issue Support an IVC follower aggregator joining the network at any time #3446
• Worked on the issue Add a SNARK verification key Proof of Bound Possession #3537
• Worked on the issue Activate dual genesis keys #3388
• Worked on the issue Activate future_snark feature by default #2814
• Worked on the issue Test scaling SNARK infrastructure to full security parameters #3153
• Worked on the issue Finalize the Mithril SNARK Book #3383
• Worked on the issue Leverage the certificate chain cache with the EarlyStopVerification mode #3521

Protocol maintenance​

• Released the new distribution 2630.1-hotfix
• Published a dev blog post Distribution 2630.1 hotfix is now available
• Completed the issue Stack overflow in aggregator and signer on release-preprod when decoding a block #3549
• Worked on the issue Upgrade to Cardano 11.1 #3346
• Worked on the issue Blocks and transaction verification fails on testing-preview #3526

High level summary​

The Plutus team has delivered a number of September milestones, and is putting the finishing touches on the remaining ones.

A new with-crypto cabal flag makes it possible to build Plinth and Plutus without the system crypto C libraries. We've also further improved the usability of the certifier in the uplc cli tool.

Work in progress includes the cost models for keepPolicies and dropPolicies (CIP-0168), and a CIP for removing the scope check during script deserialization.

Key Pull Requests Merged​

• Encode single constructor ledger types using Data.List
• Add some V4 helper functions
• Improve efficiency and consistency of Data.AssocMap
• Deserialiser optimizations
• Add a with-crypto cabal flag to build Plinth/Plutus scripts without system crypto C libraries
• Improve uplc/plc certifier usability
• Emit checkpoints in UPLC inliner
• Add more test cases for Plutus Ledger Api V4 types

Pull Requests In Progress​

• Cost models for keepPolicies and dropPolicies (CIP-0168)
• Make Data AssocMap FromData shape-safe
• Require exact product arity in generated FromData
• Evaluate Scott caseInteger scrutinee once
• Specify casing on built-in types
• Builtin Pattern Matching (CIP-0194)
• Compile BuiltinData transparently in the plugin

High level summary​

• Leios prototype development (Treasury Funding Initiative 4: Ouroboros Leios Implementation):
  • Split the Leios database into two files, one for data a node can still roll back, and one for data that is settled. A certified Endorser Block moves from the first file to the second in the background. An operator can put the two files on different disks, and give the busier file the faster disk. The same change adds garbage collection in small steps: one thread marks the rows a node no longer needs, and a second thread deletes them in paced batches, so the deletion does not hold up the rest of the node (#2261, for ouroboros-leios#969).
  • Adapted the prototype node to the two file layout, and published the size of each part as a node metric (cardano-node#6656). Added a dashboard that shows how many Endorser Blocks and transactions sit in each part, and updated the devnet configuration to match (ouroboros-leios#1054).
  • db-synthesizer now builds a Leios chain instead of a chain of empty blocks. It fills each block with transactions, puts what does not fit into an Endorser Block, and votes on each announced Endorser Block so that a later block can certify it. It also stores each Endorser Block it forges, which an earlier version dropped. The other database tools now have a Leios chain to work on (#2241, #2283).
  • db-truncater now handles a Leios chain. After it cuts the chain back to a chosen slot, it cuts the Leios database back to the same slot, drops the transactions that no Endorser Block refers to, and shrinks the file (#2262, for ouroboros-leios#1023).
  • Moved block forging out of the node kernel into a module of its own, and split it into named steps. The behaviour does not change. The new shape makes the forging path easier to follow, easier to instrument, and easier to reuse from the database tools (#2281).
• Maintenance and support (Treasury Funding Initiative 17: Maintenance and Support):
  • Dropped support for node-to-client protocol versions below v23. Version 23 shipped with node 10.7.0 in March 2026, and every client we checked already offers it. The older versions kept legacy code alive in the consensus layer (#2265).

High level overview​

This week, the Mithril team completed the missing IVC off-circuit checks, the property-based tests for the IVC pure helpers, the caching of the circuit keys with the reuse of the SNARK prover setups, and the enhancements of the end-to-end tests for the IVC SNARK. They continued implementing the circuit verification key whitelist/revoke mechanism and supporting an IVC follower aggregator joining the network at any time. They also started implementing the Relation trait for the IVC circuit and adding a Proof of Bound Possession for the SNARK verification keys.

The team completed the IPFS support in the end-to-end tests, the test infrastructure for IPFS nodes, and the summary of the IPFS PoC. They also started adding a certificate chain cache committed after chain verification in the client library.

Finally, they kept upgrading to Cardano node 11.1, reduced the aggregator compile time, and kept investigating the blocks and transactions verification failure on the testing-preview network.

Low level overview​

Features​

• Completed the issue Add missing IVC off-circuit checks #3381
• Completed the issue Add property-based tests for the IVC pure helpers #3469
• Completed the issue Cache the circuit keys and reuse the SNARK prover setups #3424
• Completed the issue Enhance end-to-end tests for IVC SNARK #3390
• Completed the issue Implement IPFS in the end to end tests #3460
• Completed the issue Prepare summary for IPFS PoC #3519
• Worked on the issue Implement circuit verification key whitelist/revoke mechanism #3148
• Worked on the issue Support an IVC follower aggregator joining the network at any time #3446
• Worked on the issue Implement Relation trait for the IVC circuit #3428
• Worked on the issue Add a SNARK verification key Proof of Bound Possession #3537
• Worked on the issue Add a certificate chain cache committed after chain verification in the client library #3520

Protocol maintenance​

• Completed the issue Implement test infrastructure for IPFS nodes #3461
• Completed the issue Reduce the aggregator compile time #3538
• Completed the issue Publication to doc.rs failed for distribution 2630 #3507
• Worked on the issue Upgrade to Cardano 11.1 #3346
• Worked on the issue Blocks and transaction verification fails on testing-preview #3526

High level overview​

This week, the Mithril team completed the behavior tests for the IVC wiring, the harmonization of the recursive and non-recursive SNARK implementations in STM, and the STM README with recursive and non-recursive examples. They continued adding the missing IVC off-circuit checks, implementing the circuit verification key whitelist/revoke mechanism, and supporting an IVC follower aggregator joining the network at any time. They also started adding property-based tests for the IVC pure helpers.

The team completed the adaptation of the documentation for the on-chain configuration parameters. They also completed the IPFS file downloader of the client and started implementing the IPFS support in the end-to-end tests.

Finally, they kept upgrading to Cardano node 11.1, started fixing the failed publication of the distribution 2630 to docs.rs, and started investigating the blocks and transactions verification failure on the testing-preview network.

Low level overview​

Features​

• Completed the issue Add behavior tests for the IVC wiring #3465
• Completed the issue Harmonize the recursive and non-recursive SNARK implementations in STM #3421
• Completed the issue Adapt documentation for on-chain configuration parameters #3398
• Completed the issue Implement an IpfsFileDownloader in the client #3459
• Completed the issue Update STM README with recursive/non-recursive examples #3385
• Worked on the issue Add missing IVC off-circuit checks #3381
• Worked on the issue Implement circuit verification key whitelist/revoke mechanism #3148
• Worked on the issue Support an IVC follower aggregator joining the network at any time #3446
• Worked on the issue Add property-based tests for the IVC pure helpers #3469
• Worked on the issue Implement IPFS in the end to end tests #3460

Protocol maintenance​

• Worked on the issue Upgrade to Cardano 11.1 #3346
• Worked on the issue Publication to doc.rs failed for distribution 2630 #3507
• Worked on the issue Blocks and transaction verification fails on testing-preview #3526