Fix bug related to non-canonical inline datums in UTxO JSON round-trips

[v0d1ch]

cardano-api's FromJSON for TxOut ignores the inlineDatumRaw field and
reconstructs HashableScriptData via scriptDataFromJson, which re-serialises
canonically. For outputs whose datum was encoded with definite-length CBOR
arrays (valid on L1 but non-canonical), H(canonical) ≠ H(original), causing
"Inline datum not equivalent to inline datum hash" on event replay.

Add parseTxOutFromJSON that reads inlineDatumRaw, deserialises the original
bytes directly, and patches inlineDatumhash to the canonical hash before
delegating to the standard parser — then restores the original bytes. Add
parseUTxOFromJSON that applies this per entry. Wire it in via an OVERLAPPING
orphan FromJSON UTxO instance in IsTx.hs so all deserialization paths
(Snapshot, HTTP handlers, event replay) are fixed without touching the IsTx
typeclass interface.

Add property tests: one pending the upstream cardano-api fix (xprop), one
verifying our parseTxOutFromJSON preserves the original datum hash.

Upstream PR: IntersectMBO/cardano-api#1238

---

• CHANGELOG updated or not needed
• Documentation updated or not needed
• Haddocks updated or not needed
• No new TODOs introduced or explained herafter

[github-actions]

Transaction cost differences

No cost or size differences found

[github-actions]

End-to-end benchmark differences

Comparing this PR (new) against master (old). Numbers come from cloud VMs, so changes under 5% are shown as ≈ and are likely run-to-run noise rather than a real regression or improvement. 🟢 = improvement, 🔴 = regression.

Baseline Scenario

Metric	master	PR	Δ
End-to-end TPS (tx/s)	569.31	580.05	≈ +10.74 (+1.9%)
Per-snapshot TPS P50 (tx/s)	4112.37	3971.55	≈ -140.82 (-3.4%)
Per-snapshot TPS P95 (tx/s)	7616.29	7520.96	≈ -95.33 (-1.3%)
Per-snapshot TPS max (tx/s)	7998.89	7964.34	≈ -34.55 (-0.4%)
Avg. Confirmation Time (ms)	507.30	497.10	≈ -10.20 (-2.0%)
P50 confirmation (ms)	510.20	500.70	≈ -9.50 (-1.9%)
P95 confirmation (ms)	520.80	511.60	≈ -9.20 (-1.8%)
P99 confirmation (ms)	521.10	511.80	≈ -9.30 (-1.8%)
Invalid txs	0.00	0.00	≈ +0.00 (n/a%)

Three local nodes

Metric	master	PR	Δ
End-to-end TPS (tx/s)	307.29	301.23	≈ -6.06 (-2.0%)
Per-snapshot TPS P50 (tx/s)	1006.00	977.49	≈ -28.51 (-2.8%)
Per-snapshot TPS P95 (tx/s)	3255.75	2344.99	🔴 -910.76 (-28.0%)
Per-snapshot TPS max (tx/s)	3785.24	2474.97	🔴 -1310.27 (-34.6%)
Avg. Confirmation Time (ms)	2633.10	2676.50	≈ +43.40 (+1.6%)
P50 confirmation (ms)	2686.90	2747.10	≈ +60.20 (+2.2%)
P95 confirmation (ms)	2904.40	2942.90	≈ +38.50 (+1.3%)
P99 confirmation (ms)	2912.50	2948.80	≈ +36.30 (+1.2%)
Invalid txs	0.00	0.00	≈ +0.00 (n/a%)

[github-actions]

Transaction costs

Sizes and execution budgets for Hydra protocol transactions. Note that unlisted parameters are currently using arbitrary values and results are not fully deterministic and comparable to previous runs.

Metadata
Generated at	2026-07-09 08:50:25.943397226 UTC
Max. memory units	14000000
Max. CPU units	10000000000
Max. tx size (kB)	16384

Script summary

Name	Hash	Size (Bytes)
νHead	fd75e24c9ea915ce8e48d3ff1d0c54ad09cc01191c24416ad7dba4a3	11621
μHead	83a964e973c065bbe70588f5e089817f92182ae81743e7a54cf3e29e*	4856
νDeposit	c78e8c9205721eb3ef4410f3db9c6169fa6db497c24641d29c20529c	1615
νCRS	09db7ee6cf7a4b358dd5c8a2f19d2c048336ffc5a01ef35a47ca7072	2736

• The minting policy hash is only usable for comparison. As the script is parameterized, the actual script is unique per head.

Init transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	5351	9.19	3.03	0.48
2	5445	9.56	3.14	0.49
3	5545	10.01	3.29	0.50
5	5736	11.43	3.76	0.52
10	6217	13.51	4.40	0.56
50	10058	34.52	10.96	0.95
100	14859	61.43	19.39	1.44
115	16298	70.47	22.24	1.60

Cost of Increment Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	2282	18.33	6.59	0.45
2	2406	19.33	7.53	0.47
3	2540	19.67	8.24	0.48
5	2806	21.49	10.04	0.52
10	3456	26.59	14.74	0.62
50	8700	65.75	51.54	1.44
75	11974	89.59	74.37	1.94

Cost of Decrement Transaction

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	599	16.03	5.75	0.35
2	728	16.92	6.65	0.37
3	861	17.84	7.56	0.39
5	1125	19.62	9.35	0.43
10	1782	24.10	13.84	0.52
50	7021	62.14	50.30	1.32
75	10295	86.34	73.20	1.83

Close transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	593	15.49	10.37	0.38
3	858	17.31	12.18	0.42
5	1117	19.11	13.99	0.45
10	1773	23.66	18.51	0.55
50	7013	61.78	55.09	1.36
75	10288	86.14	78.09	1.86

Contest transaction costs

Parties	Tx size	% max Mem	% max CPU	Min fee ₳
1	619	18.79	13.48	0.43
2	751	19.85	14.43	0.45
3	890	20.97	15.40	0.47
5	1149	23.12	17.31	0.51
10	1799	28.45	22.07	0.62
50	7044	73.86	60.80	1.50
73	10057	99.29	82.87	1.99

FanOut transaction costs

Involves spending head output and burning head tokens. Uses ada-only UTXO for better comparability.

Parties	UTxO	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
10	0	0	5529	22.68	41.73	0.88
10	1	57	5564	25.03	44.25	0.92
10	5	285	5699	35.28	54.57	1.08
10	10	568	5867	49.29	67.85	1.30
10	20	1139	6208	81.82	95.83	1.78
10	20	1137	6206	81.82	95.83	1.78

PartialFanOut transaction costs

Largest chunk of ada-only outputs that can be distributed in one partial fanout step, computed dynamically. The last row is the maximum total UTxO count where at least one output can still be distributed.

Distributed	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
11	570	987	34.31	65.19	0.94
25	1309	1428	67.64	98.26	1.47
30	1308	1427	67.64	98.26	1.47
40	1309	1428	67.64	98.26	1.47
50	1307	1426	67.64	98.26	1.47
100	1309	1428	67.64	98.26	1.47
150	1307	1422	67.64	98.26	1.47
200	1307	1426	67.64	98.26	1.47
200	1309	1428	67.64	98.26	1.47

PartialFanOut transaction costs (with native tokens)

Largest chunk of native-token outputs that can be distributed in one partial fanout step, computed dynamically. The last row is the maximum total UTxO count where at least one output can still be distributed.

Distributed	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
11	1110	1598	41.40	67.74	1.04
25	2247	2500	75.99	98.03	1.58
30	2352	2610	75.97	98.07	1.59
40	1953	2192	75.97	97.97	1.57
50	2142	2391	75.99	98.03	1.58
100	1995	2237	75.97	97.97	1.57
150	2226	2475	75.97	98.03	1.58
200	2310	2567	75.99	98.08	1.58
200	2058	2303	75.99	97.98	1.57

FinalPartialFanOut transaction costs (with native tokens)

Terminal partial fanout step (FanoutProgress → Final) with outputs carrying a native token. Burns all head tokens and proves accumulator exhaustion via BLS proof.

Distributed	UTxO (bytes)	Tx size	% max Mem	% max CPU	Min fee ₳
1	111	5415	21.54	43.18	0.87
5	535	5756	35.15	54.71	1.08
10	1120	6236	53.23	69.49	1.36
10	1070	6185	53.35	69.50	1.35

End-to-end benchmark results

This page is intended to collect the latest end-to-end benchmark results produced by Hydra's continuous integration (CI) system from the latest master code.

Please note that these results are approximate as they are currently produced from limited cloud VMs and not controlled hardware. Rather than focusing on the absolute results, the emphasis should be on relative results, such as how the timings for a scenario evolve as the code changes.

Generated at 2026-07-09 08:50:09.137562698 UTC

Baseline Scenario

Number of nodes	1
Number of txs	300
Avg. Confirmation Time (ms)	517.8
P99	531.1ms
P95	530.8ms
P50	520.8ms
End-to-end TPS	559.40 tx/s
Snapshots observed	4
Per-snapshot TPS P50	4133.07 tx/s
Per-snapshot TPS P95	8102.01 tx/s
Per-snapshot TPS max	8530.62 tx/s
Number of Invalid txs	0
Fanout outputs	0

Three local nodes

Number of nodes	3
Number of txs	900
Avg. Confirmation Time (ms)	2581.5
P99	2847.8ms
P95	2831.0ms
P50	2630.5ms
End-to-end TPS	313.08 tx/s
Snapshots observed	10
Per-snapshot TPS P50	1014.29 tx/s
Per-snapshot TPS P95	2647.76 tx/s
Per-snapshot TPS max	2928.10 tx/s
Number of Invalid txs	0
Fanout outputs	0

Scenario benchmark results

This page collects results from the scenario matrix: every combination of cluster size, UTxO shape, and incremental-ops mode is exercised by CI from the latest master code and reported below.

Numbers are approximate. They come from cloud VMs rather than controlled hardware, so the useful signal is the relative change between cells and between commits, not the absolute throughput.

Generated at 2026-07-09 08:59:19.226145621 UTC

Summary across cells

TPS columns are rates (transactions per second); Wall clock (s) is the measured elapsed time from the first tx submission to the last confirmation. Times are rounded to one decimal.

Scenario	Txs	Wall clock (s)	End-to-end TPS (tx/s)	Per-snapshot p50 TPS (tx/s)	Avg conf (ms)	P95 conf (ms)
Nodes=1, Constant, incremental ops off, fire and forget	30	0.1	458.50	2215.91	64.7	65.1
Nodes=1, Constant, incremental ops off, wait for tx valid	30	0.2	161.73	174.95	6.1	8.5
Nodes=1, Growing, incremental ops off, fire and forget	30	0.1	415.40	865.02	71.1	72.0
Nodes=1, Growing, incremental ops off, wait for tx valid	30	0.3	117.44	118.05	8.4	10.9
Nodes=1, Mixed, incremental ops off, fire and forget	30	0.1	488.34	2084.73	60.7	61.2
Nodes=1, Mixed, incremental ops off, wait for tx valid	30	0.2	131.95	136.39	7.5	10.8
Nodes=2, Constant, incremental ops off, fire and forget	60	0.2	397.65	1624.09	149.1	149.9
Nodes=2, Constant, incremental ops off, wait for tx valid	60	0.5	116.16	122.26	17.0	22.7
Nodes=2, Growing, incremental ops off, fire and forget	60	0.2	334.79	683.54	177.1	178.9
Nodes=2, Growing, incremental ops off, wait for tx valid	60	0.9	64.19	68.07	30.6	45.3
Nodes=2, Mixed, incremental ops off, fire and forget	60	0.2	387.49	1978.97	153.3	154.5
Nodes=2, Mixed, incremental ops off, wait for tx valid	60	0.7	80.73	88.65	24.5	36.1
Nodes=3, Constant, incremental ops off, fire and forget	90	0.3	350.49	1598.58	253.9	256.4
Nodes=3, Constant, incremental ops off, wait for tx valid	90	1.0	93.25	84.25	31.5	44.0
Nodes=3, Growing, incremental ops off, fire and forget	90	0.3	272.34	489.33	325.6	329.1
Nodes=3, Growing, incremental ops off, wait for tx valid	90	2.0	44.76	44.46	63.6	99.9
Nodes=3, Mixed, incremental ops off, fire and forget	90	0.3	317.93	1015.10	278.6	281.8
Nodes=3, Mixed, incremental ops off, wait for tx valid	90	1.4	63.38	60.95	46.3	65.7

Nodes=1, Constant, incremental ops off, fire and forget

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	64.7
P99	65.2ms
P95	65.1ms
P50	64.9ms
End-to-end TPS	458.50 tx/s
Snapshots observed	2
Per-snapshot TPS P50	2215.91 tx/s
Per-snapshot TPS P95	4194.94 tx/s
Per-snapshot TPS max	4370.85 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=1, Constant, incremental ops off, wait for tx valid

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	6.1
P99	9.0ms
P95	8.5ms
P50	5.6ms
End-to-end TPS	161.73 tx/s
Snapshots observed	30
Per-snapshot TPS P50	174.95 tx/s
Per-snapshot TPS P95	188.69 tx/s
Per-snapshot TPS max	190.83 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=1, Growing, incremental ops off, fire and forget

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	71.1
P99	72.0ms
P95	72.0ms
P50	71.6ms
End-to-end TPS	415.40 tx/s
Snapshots observed	2
Per-snapshot TPS P50	865.02 tx/s
Per-snapshot TPS P95	1627.26 tx/s
Per-snapshot TPS max	1695.01 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=1, Growing, incremental ops off, wait for tx valid

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	8.4
P99	13.0ms
P95	10.9ms
P50	8.4ms
End-to-end TPS	117.44 tx/s
Snapshots observed	30
Per-snapshot TPS P50	118.05 tx/s
Per-snapshot TPS P95	161.10 tx/s
Per-snapshot TPS max	171.01 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=1, Mixed, incremental ops off, fire and forget

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	60.7
P99	61.2ms
P95	61.2ms
P50	61.0ms
End-to-end TPS	488.34 tx/s
Snapshots observed	2
Per-snapshot TPS P50	2084.73 tx/s
Per-snapshot TPS P95	3944.46 tx/s
Per-snapshot TPS max	4109.77 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=1, Mixed, incremental ops off, wait for tx valid

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	1
Number of txs	30
Avg. Confirmation Time (ms)	7.5
P99	11.9ms
P95	10.8ms
P50	7.2ms
End-to-end TPS	131.95 tx/s
Snapshots observed	30
Per-snapshot TPS P50	136.39 tx/s
Per-snapshot TPS P95	177.98 tx/s
Per-snapshot TPS max	196.75 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=2, Constant, incremental ops off, fire and forget

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	149.1
P99	150.0ms
P95	149.9ms
P50	149.4ms
End-to-end TPS	397.65 tx/s
Snapshots observed	2
Per-snapshot TPS P50	1624.09 tx/s
Per-snapshot TPS P95	3078.96 tx/s
Per-snapshot TPS max	3208.28 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=2, Constant, incremental ops off, wait for tx valid

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	17.0
P99	26.3ms
P95	22.7ms
P50	16.2ms
End-to-end TPS	116.16 tx/s
Snapshots observed	60
Per-snapshot TPS P50	122.26 tx/s
Per-snapshot TPS P95	152.64 tx/s
Per-snapshot TPS max	167.19 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=2, Growing, incremental ops off, fire and forget

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	177.1
P99	179.0ms
P95	178.9ms
P50	177.7ms
End-to-end TPS	334.79 tx/s
Snapshots observed	2
Per-snapshot TPS P50	683.54 tx/s
Per-snapshot TPS P95	1292.05 tx/s
Per-snapshot TPS max	1346.14 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=2, Growing, incremental ops off, wait for tx valid

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	30.6
P99	49.9ms
P95	45.3ms
P50	30.7ms
End-to-end TPS	64.19 tx/s
Snapshots observed	60
Per-snapshot TPS P50	68.07 tx/s
Per-snapshot TPS P95	104.35 tx/s
Per-snapshot TPS max	115.79 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=2, Mixed, incremental ops off, fire and forget

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	153.3
P99	154.6ms
P95	154.5ms
P50	153.6ms
End-to-end TPS	387.49 tx/s
Snapshots observed	2
Per-snapshot TPS P50	1978.97 tx/s
Per-snapshot TPS P95	3753.57 tx/s
Per-snapshot TPS max	3911.31 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=2, Mixed, incremental ops off, wait for tx valid

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	2
Number of txs	60
Avg. Confirmation Time (ms)	24.5
P99	66.3ms
P95	36.1ms
P50	22.7ms
End-to-end TPS	80.73 tx/s
Snapshots observed	60
Per-snapshot TPS P50	88.65 tx/s
Per-snapshot TPS P95	129.51 tx/s
Per-snapshot TPS max	151.31 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=3, Constant, incremental ops off, fire and forget

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	253.9
P99	256.5ms
P95	256.4ms
P50	255.0ms
End-to-end TPS	350.49 tx/s
Snapshots observed	2
Per-snapshot TPS P50	1598.58 tx/s
Per-snapshot TPS P95	3033.34 tx/s
Per-snapshot TPS max	3160.87 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=3, Constant, incremental ops off, wait for tx valid

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	31.5
P99	47.0ms
P95	44.0ms
P50	31.0ms
End-to-end TPS	93.25 tx/s
Snapshots observed	62
Per-snapshot TPS P50	84.25 tx/s
Per-snapshot TPS P95	173.36 tx/s
Per-snapshot TPS max	208.75 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=3, Growing, incremental ops off, fire and forget

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	325.6
P99	329.2ms
P95	329.1ms
P50	328.1ms
End-to-end TPS	272.34 tx/s
Snapshots observed	2
Per-snapshot TPS P50	489.33 tx/s
Per-snapshot TPS P95	925.93 tx/s
Per-snapshot TPS max	964.74 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=3, Growing, incremental ops off, wait for tx valid

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	63.6
P99	129.9ms
P95	99.9ms
P50	62.7ms
End-to-end TPS	44.76 tx/s
Snapshots observed	64
Per-snapshot TPS P50	44.46 tx/s
Per-snapshot TPS P95	103.57 tx/s
Per-snapshot TPS max	148.53 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=3, Mixed, incremental ops off, fire and forget

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	278.6
P99	281.9ms
P95	281.8ms
P50	280.9ms
End-to-end TPS	317.93 tx/s
Snapshots observed	2
Per-snapshot TPS P50	1015.10 tx/s
Per-snapshot TPS P95	1924.88 tx/s
Per-snapshot TPS max	2005.75 tx/s
Number of Invalid txs	0
Fanout outputs	0

Nodes=3, Mixed, incremental ops off, wait for tx valid

Each client first grows its UTxO set (1-in to 2-out) for half of its tx budget, then contracts it back (2-in to 1-out) for the remainder.

Number of nodes	3
Number of txs	90
Avg. Confirmation Time (ms)	46.3
P99	71.6ms
P95	65.7ms
P50	44.9ms
End-to-end TPS	63.38 tx/s
Snapshots observed	62
Per-snapshot TPS P50	60.95 tx/s
Per-snapshot TPS P95	143.46 tx/s
Per-snapshot TPS max	166.04 tx/s
Number of Invalid txs	0
Fanout outputs	0