Cardano Updates

The root cause was in confirmedUTxO inside onOpenNetworkReqSn: it always
  included utxoToCommit unconditionally. When a new ReqSn with no deposit
  arrived after recovery, the recovered deposit was still part of the base
  UTxO used to apply transactions, and with no withoutUTxO to strip it
  back out, it baked into the new snapshot's utxo field.

* Add Nuvola Blog Interview

* Fix URL and Update Image Reference

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Co-authored-by: Denicio Bute <>

  The new accumulator-based headIsFinalizedWith validator checks that the
  head input value covers all distributed outputs. The test head output was
  missing UTxO.totalValue, causing H4 (HeadValueIsNotPreserved) failures.

Signed-off-by: Sasha Bogicevic <[email protected]>

* feat: add conway governance queries

* feat: update tests fgor gow queries

Signed-off-by: Sasha Bogicevic <[email protected]>

  Remove utxoHash/alphaUTxOHash/omegaUTxOHash from ClosedDatum, all
  Close/Contest redeemers, and the snapshot signing tuple. The BLS
  accumulator already commits to the full UTxO set (utxo ∪ alpha ∪
  omega), making the three separate SHA256 hashes redundant.

  Full fanout now verifies outputs via a KZG membership proof (same as
  partial fanout) rather than hash comparison. The Fanout redeemer gains
  proof and crsRef fields; the three output-count fields are dropped.

  Snapshot signing shrinks from a 7-tuple to a 4-tuple
  (headId, version, snapshotNumber, accumulatorHash).

Signed-off-by: Sasha Bogicevic <[email protected]>

Signed-off-by: Sasha Bogicevic <[email protected]>

Also reduce a diff in the test code

Signed-off-by: Sasha Bogicevic <[email protected]>

  Replace the hardcoded numToDistribute = totalUTxO - 1 in the partial
  fanout benchmarks with a binary search that finds the largest chunk
  actually fitting within both the tx size and execution budget, mirroring
  findFittingFanoutTx in the real node. The Remaining column in the output
  table now carries meaningful information instead of always showing 1.

  Also add ContestationDeadlineOutsideTimeHorizon to the PostTxError
  oneOf in api.yaml, which was defined in Chain.hs but missing from the
  schema, causing ServerOutputSpec to fail.

Signed-off-by: Sasha Bogicevic <[email protected]>

  computeFinalPartialFanOutCost was capped at 7 (fanoutChunkSize), hiding
  the real tx-size limit for the terminal fanout step. Now it sweeps a wide
  range and searches for the actual maximum, using a single preceding output
  as minimal setup to reach FanoutProgress.

  computePartialFanOutMixedCost also dropped its fanoutChunkSize cap and
  now distributes all-but-one outputs, consistent with the nominal benchmark.
  The stale description mentioning fanoutChunkSize is corrected accordingly.

Signed-off-by: Sasha Bogicevic <[email protected]>

Signed-off-by: Sasha Bogicevic <[email protected]>

  fanoutChunkSize and fanoutOutputThreshold are now defined once in
  Test.Hydra.Tx.Fixture and imported wherever needed, removing the
  per-file duplicates.

  prepareTxToPost gains explicit FanoutTx/FinalPartialFanoutTx branches
  (error) so GHC's exhaustiveness checker catches any future unhandled
  constructor, instead of silently falling through a wildcard.

  The two deadline-slot conversions in mkChain.postTx now throw
  FailedToConstructFanoutTx (a PostTxError Tx) instead of userError,
  so the exception is caught by Node.hs's PostTxError handler rather
  than propagating uncaught and crashing the node.