This is the monthly report on the progress of the Hydra and Mithril projects for September 2025. It serves as preparation for, and a written summary of, the monthly stakeholder review meeting. The meeting is announced on our Discord channels and held on Google Meet. This month, the meeting took place on September 24, 2025, using the presentation slides; the recording is also available.
Mithril
Issues and pull requests closed in September
Roadmap
Below are the latest updates on our roadmap:
- DMQ signature diffusion prototype (#2402) – integrated the Haskell DMQ node with the Mithril nodes and started testing end-to-end communication
- Support multiple proof systems in STM (#2550) – added support for multiple proof systems in the STM library
- Cardano and Mithril Docker image — proof of concept (#2541) – created a prototype Docker image that bundles Cardano and Mithril nodes.
DMQ implementation update
Here is the current status of the DMQ implementation:
| Mini-protocols | Pallas | Mithril Signer | Mithril Aggregator | Mithril Relay | Haskell DMQ Node |
|---|---|---|---|---|---|
| N2C submission | ✓ | ✓ | - | ✓* | ✓ |
| N2C notification | ✓ | Planned | ✓ | ✓* | ✓ |
| N2N diffusion | Planned | - | - | - | ✓ |
The network team completed the Haskell DMQ node implementation. We began integrating it with the Mithril nodes and started testing end-to-end communication. We also made protocol adjustments that are reflected in CIP-0137 and in the Pallas library.
Distributions
In September, we completed the following:
- Released the new distribution
2537 - Stabilized the ledger state snapshot converter command in the Mithril client CLI
- Stabilized the incremental Cardano database certification backend.
In October, the following events are planned:
- Release of a new distribution (
2542).
Dev blog
We published the following posts:
Bundling Cardano and Mithril nodes in a Docker image
We have developed a prototype Docker image that extends the existing Cardano node image with integrated Mithril functionality. This prototype includes:
- An embedded, statically built Mithril signer
- Pre-configured Mithril-specific configuration files
- A wrapped Cardano node endpoint that automatically launches the Mithril signer in the background when the node operates as a block producer.
This prototype image can be started with the same configuration parameters as the original Cardano node image, which should make it easy for users to deploy a combined Cardano and Mithril setup. We will continue to work on this prototype, as well as other options to simplify Mithril deployments for SPOs and enhance protocol adoption.
Error detection in the verification of the Cardano database
We improved Cardano database verification in both the Mithril client library and CLI. The enhanced verification now generates detailed reports listing tampered or missing files within the database. This gives users better visibility into integrity issues so they can identify problems more precisely and take targeted corrective actions. The implementation required significant refactoring of the underlying verification logic to achieve more accurate detection and comprehensive reporting.
Protocol status
The protocol operated smoothly on the release-mainnet network with the following metrics:
- Registered stake:
4.7B₳(22%of the Cardano network) - Registered SPOs:
245(9%of the Cardano network) - Full Cardano database restorations:
945restorations - Signer software adoption:
77.9%of the SPOs are running a recent version (one of the last three releases).
You can find more information on the Mithril protocol insights dashboard.
Hydra
Issues and pull requests closed in September
This month, notable roadmap updates include:
Partial ada commits
We had a very nice feature request to allow a user to commit only part of a UTXO: Allow partial ada commit. We have implemented this in #2160 and continued to address follow-up work in #2185 and #2282.
Blockfrost enhancements
We made improvements to Blockfrost error messages and timeout options.
Enable deposit recovery from any state
We updated the API server and hydra-tui to allow recovery of
deposits even after the head you intended to deposit into is closed. See
#2217 and
#2256 for further
details.
Roadmap update
- Delivered recovering in a closed state
- Working on HTLC between two Hydra heads
- Starting work on partial fanout
- Starting work on a light-weight node via Raspberry Pi.
Links
The monthly review meeting for September 2025 took place on September 24, 2025, via Google Meet. The presentation slides and the recording are available for review.