csoai/measurement-capsules

Signed measurement capsules v0.2 (2026-09-26 index)

Read first: one field in these files is superseded. The index and the batch records carry private_until: "owner approves publication", written before publication was approved. Publication was approved on 2026-09-26; the signed erratum v0.2/publication/2026-09-26-erratum.json supersedes that one field and nothing else. No capsule, count or signature changed.

A measurement capsule is one content-addressed statement of what one instrument observed about one subject at one time, with the declared value, the observed value, the differential, its limitations and a state. Capsules are not signed one by one: each batch's signed record.json binds its capsules through an RFC 6962 Merkle root over their ids, and a signed daily index binds every batch. This dataset holds every file of the 2026-09-26 index published at https://councilof.ai/measurement-capsules/v0.2/, byte for byte, plus two viewer tables derived from them.

Read from the signed index payload (v0.2/index.signed.json → payload): 13,184 capsules in 8 batches, index root 85533b833d36f8a4165da34206ee6e39f7434c646c8a2c381d251391ceec366d, as of 2026-09-26T10:34:15Z.

batch	what each capsule states	capsules	states (from the batch's record.json)	RFC 6962 Merkle root
a2a_card	does a published A2A agent card verify under the key it references	33	VERIFIED 13, UNCHECKABLE 12, 8 in the state for a signature that does not verify	bf12f4ad340a11a14ecbd359ba90b3aaebb36bb75bcf9e11f433148441bae436
contract_parity	is the tool set an MCP server's surfaces declare the tool set the live server lists	9,148	CONSISTENT 5,570, INCONSISTENT 2,905, UNCHECKABLE 673	70403984d857b7b167d0010608f79c5407bc8642435eb72e7644c83918b1a788
cross_ledger	is the issuer's declared token deployment on a ledger the one the ledger shows, and what the ledger's own state says is issued	353	CONSISTENT 101, OPERATOR_API 77, UNCHECKABLE 52, STATE_PROOF_VERIFIED 49, LISTED_NOT_READ 34, STATE_PROOF_RECORDED 10, TOTAL_COMPLETE 10, TOTAL_PARTIAL 8, PERMISSIONED_NOT_READABLE 6, INCONSISTENT 4, ISSUER_LIST_UNAVAILABLE 2	a6e3fd14b1cc68072d919bfc59565161e59c492f97c775bbebefd48705770bf9
mill_cross_runtime-5ae00c1f4c2e	does a signed evaluation result reproduce on a second runtime	14	NOT_REPRODUCED 7, REPRODUCED_ITEMWISE 5, REPRODUCED_AGGREGATE_ONLY 2	5ae00c1f4c2ed290fb91206f29372d0df3e61478c568d4797855502e751ebff6
mill_cross_runtime-78226433e9e4	does a signed evaluation result reproduce on a second runtime	140	NOT_REPRODUCED 82, REPRODUCED_ITEMWISE 49, REPRODUCED_AGGREGATE_ONLY 9	78226433e9e433b311e067ee56fcbaf415f6dc57301254f3bb4922a0b8053cf6
public_signals	what a public counter reads on a day, from its source	118	MEASURED 103, UNCHECKABLE 12, PARTIAL 3	ef67f71508192f08f1aedb00276592ee81e85661e7c3421bec036d4e7b9adb42
self_parity	does an index's listing of a CSOAI offering say what CSOAI actually serves (CSOAI's own entries)	138	NOT_LISTED 55, CONSISTENT 37, UNCHECKABLE 37, INCONSISTENT 8, NOT_DECLARED 1	53d5c6b23a13c464546d31ab18abcf1fae3990961019fc2443748d62922acf3a
tool_drift	are the tools an endpoint advertised at one observation the tools it advertised at the next	3,240	UNCHECKABLE 1,755, UNCHANGED_AT_NAME_GRANULARITY 1,485	fd0f514e03dd825698a3eab57d33431b09e62e442f85c7592db50f2371e9d2df

A state is the instrument's reading of one subject on one day, never a grade; UNCHECKABLE means the instrument could not decide and is counted, not scored. Each capsule carries authority_state: NONE (measurement only; it grants no execution authority).

What this is not

• Not a ranking or approval of any server, agent, issuer, asset or model.
• Not a population total: each batch covers the subjects its source record covers.
• self_parity and the SELF rows of public_signals are about CSOAI's own offerings and counters; they are reported beside the third-party batches and never added to them.
• The per-endpoint lookup shards under https://councilof.ai/measurement-capsules/v0.2/endpoints/ are a derived index over these capsules and are not copied here.

Files

file	bytes	sha256	what
latest.json	196	52e0e2855098aec4ec17d830951cdb7d974e0a612978d44c9d5081d6610ebfd0	pointer to the current version
v0.2/a2a_card/capsules.jsonl.gz	7,916	ba413e8160120205d8b9ec87fec95fa9e0f3ac2e6c858d4e6e807851882cd661	the capsules, canonical JSON lines sorted by capsule_id
v0.2/a2a_card/leaves.json	2,812	d509c87797581f871dfcca872c55449623f862e9a7058c51d7a5a2abbc4446fe	the batch's Merkle leaves (capsule ids)
v0.2/a2a_card/record.json	3,338	180a16f838f33372e1e6345fb272d7b3427a55dacee5571c34a6947a116cc6b6	the batch record: adapter, states, Merkle root, capsule file hashes
v0.2/a2a_card/record.json.ots	635	5243568f0fb91879c58b21e8e350a45d7090c39c32984e80800f6aee8bf55acf	OpenTimestamps proof
v0.2/a2a_card/record.signed.json	1,557	d379b0096adf4537af48b3c046c65a76c2b4a45c371943985e1e8193d2f93e2f	Ed25519 signature over a payload pinning record.json, the capsule file and the Merkle root
v0.2/anchors.json	3,674	99788acf2317092b0cecf47e52cb74ac88f55f6a89fcfd5c7be47faef0ce8ad3	where the index bytes are anchored, read from the anchor files
v0.2/contract_parity/capsules.jsonl.gz	1,992,620	7b24218a5616d4deb2461ddca0ff97dc7eafc5f094be77ca1f772f05ac862d6d	the capsules, canonical JSON lines sorted by capsule_id
v0.2/contract_parity/leaves.json	613,530	4f0903244ae0aa20b9cd569de5dd7fcdfa572d4038c1b5a6d4d370618d295ee2	the batch's Merkle leaves (capsule ids)
v0.2/contract_parity/record.json	5,150	1b9186699b27ac5bc13c4b211f7a5f1317aee96e0c85c27668ac21b9214af357	the batch record: adapter, states, Merkle root, capsule file hashes
v0.2/contract_parity/record.json.ots	705	47a09989614e81efe78c59ead13e8ed9aa2fcc915091f80b52386352c0cf252e	OpenTimestamps proof
v0.2/contract_parity/record.signed.json	1,584	84b4d17bb7056960e00789056fdc27f5ed5ecaec1d7495440d7815b9e9ce74c2	Ed25519 signature over a payload pinning record.json, the capsule file and the Merkle root
v0.2/cross_ledger/capsules.jsonl.gz	111,954	af25aa3413d97f3d14406d51b8bf0013198ba26b6359eaadf12370081e5830b1	the capsules, canonical JSON lines sorted by capsule_id
v0.2/cross_ledger/leaves.json	24,262	091e9609bca4f2dccb74fe73256cca801ced2b51250f16f764ff0fce8e849057	the batch's Merkle leaves (capsule ids)
v0.2/cross_ledger/record.json	12,130	ace6cbe3697ed1f6715ea2f921eaad07c82cab795fb86609a3d16b3c956465df	the batch record: adapter, states, Merkle root, capsule file hashes
v0.2/cross_ledger/record.json.ots	705	13ed380424d7386aee72de5bbdc26152bf0731c9ae9c1915902863c26a86a371	OpenTimestamps proof
v0.2/cross_ledger/record.signed.json	1,803	9f16a1d677bca6d96720ec39fad8494805f7444d5d79e2824413f91bf91f1385	Ed25519 signature over a payload pinning record.json, the capsule file and the Merkle root
v0.2/index.json	34,150	ee3d921750d40456eb58ed24d2a9ba141d6fc1d16510ddd338166c4f5620b72a	the day's index over every batch: roots, counts, index root
v0.2/index.json.ots	1,532	e2843a3682e31fa153250a41525d7e2844496b2ac945934927cd3c6e66b731fd	OpenTimestamps proof
v0.2/index.signed.json	2,934	18be27315446e0f543e62a4e516cce10976a07ef770dbdb839e8bf9329546415	Ed25519 signature over the index
v0.2/mill_cross_runtime-5ae00c1f4c2e/capsules.jsonl.gz	8,040	a8dc6d18a2835c8bead883b17c5a71257da40faf63381bce2f0f98e6ab366c8d	the capsules, canonical JSON lines sorted by capsule_id
v0.2/mill_cross_runtime-5ae00c1f4c2e/leaves.json	1,580	00111f3e8fa28132c6a2d8bfea15149a017291bf54f64cddc54e353e3d50ef30	the batch's Merkle leaves (capsule ids)
v0.2/mill_cross_runtime-5ae00c1f4c2e/record.json	3,613	32ece857c94062f41a03aad9e269532cdbe5dc0a576ed20110edc4ecacb0468d	the batch record: adapter, states, Merkle root, capsule file hashes
v0.2/mill_cross_runtime-5ae00c1f4c2e/record.json.ots	670	18a726ece04b3b550f985f68cd767b4a283e430eb1e3102b2ceb3e26202c5203	OpenTimestamps proof
v0.2/mill_cross_runtime-5ae00c1f4c2e/record.signed.json	1,616	4bd0799e4b01be5794733510030c021438957e490bf0108e7ef2424f08f55ad8	Ed25519 signature over a payload pinning record.json, the capsule file and the Merkle root
v0.2/mill_cross_runtime-78226433e9e4/capsules.jsonl.gz	75,831	cf7d3db1cf664b99ad89593dd44109263d14b28c2026c8c53b5c65cb949673f8	the capsules, canonical JSON lines sorted by capsule_id
v0.2/mill_cross_runtime-78226433e9e4/leaves.json	10,023	20f5ba19f13643bb6905f1e6693761b5c3a72dd41c77e92399758c8ffce8b2ff	the batch's Merkle leaves (capsule ids)
v0.2/mill_cross_runtime-78226433e9e4/record.json	19,318	422fa6377b274bab095e8e875f67d087a275417c14c90a4c4e4cedb56ca9a5ff	the batch record: adapter, states, Merkle root, capsule file hashes
v0.2/mill_cross_runtime-78226433e9e4/record.json.ots	705	0eeb913f7e36161c2e46dedefc68997de65294db5c515e03176bd38f4e483607	OpenTimestamps proof
v0.2/mill_cross_runtime-78226433e9e4/record.signed.json	1,637	12522ad5cab221f1c7291401d21e5b0c29750adec829387ca6f43d3ac93de2c3	Ed25519 signature over a payload pinning record.json, the capsule file and the Merkle root
v0.2/public_signals/capsules.jsonl.gz	19,788	5d8a0c632c0158116f2973c4256afc6bb03fc18957dab72eed75ce9e284ce770	the capsules, canonical JSON lines sorted by capsule_id
v0.2/public_signals/leaves.json	8,515	3c79d8555bef3cb10a16fb8f2a6247f8dbb0d5457416bece04b1521bc0f2c610	the batch's Merkle leaves (capsule ids)
v0.2/public_signals/record.json	2,603	abbcec606003f5eab774c6990f32b6c95c4eca692e5467c5e987fe5d426c8690	the batch record: adapter, states, Merkle root, capsule file hashes
v0.2/public_signals/record.json.ots	670	49b8ea5ed8259bdef6aed4c2c69012a5aff4628cf47d78acc5ffd7585084e83a	OpenTimestamps proof
v0.2/public_signals/record.signed.json	1,567	e12dfa01e8cd21ae6f00583b8c14e5d159076af2f59f0c5f7844954666e5adae	Ed25519 signature over a payload pinning record.json, the capsule file and the Merkle root
v0.2/publication/2026-09-26-erratum.json	12,759	068f1c9b9f029f46a46d0fe6306a83491254f8d69c5dd01605c3214ec02eeec9	dated erratum: the private_until field in the listed files is obsolete
v0.2/publication/2026-09-26-erratum.json.ots	635	da7d8646a8429e45d131715b0857945581926569908bbfcec6961722d4d8ec0d	OpenTimestamps proof
v0.2/publication/2026-09-26-erratum.signed.json	1,860	925128abde6e84e64abe70575b2cd7521dd750e93b9024757142b0d525a81d6b
v0.2/publication/2026-09-26.json	2,069	effd4713967cff6e03e548f752c87cbb7405a869f15871b00ac92c950201a804	publication state of the index (PUBLIC, owner-approved 2026-09-26)
v0.2/publication/2026-09-26.json.ots	635	a86b67fb4f08b002fcf23eeb31a76645b3bcb6a83bc3ed532391839e08a64ebb	OpenTimestamps proof
v0.2/publication/2026-09-26.signed.json	1,785	df7fff513f5967337187c6ab27d14db18882c0096c0f7c2317aab2a24877e3fa
v0.2/self_parity/capsules.jsonl.gz	21,624	dc703838bd4c5e9db443f23e54d972343d5c9fdcaf258397472194c5e8267c64	the capsules, canonical JSON lines sorted by capsule_id
v0.2/self_parity/leaves.json	9,847	f1e773743b8fad3434572a740a42deac9a4e431e01412dd4f6f3075d1782d133	the batch's Merkle leaves (capsule ids)
v0.2/self_parity/record.json	2,412	57d697af67fc40fc4ce206aec5407e1e6873684ae7e4387cb3a06c125a700337	the batch record: adapter, states, Merkle root, capsule file hashes
v0.2/self_parity/record.json.ots	635	0504f41051179f3c74a2adc9c81e0fe8373e6eb5ba190ed9ce2b1d1d0b860638	OpenTimestamps proof
v0.2/self_parity/record.signed.json	1,608	697f2fa62243841e5cd48976c3f70a1e1fbc9b59b7a81ad5dc45bc57132addee	Ed25519 signature over a payload pinning record.json, the capsule file and the Merkle root
v0.2/tool_drift/capsules.jsonl.gz	646,582	febe9aed6140c3cc12a0c256fb0ffa9e76bc66a19342f086af03ee60c7baa7aa	the capsules, canonical JSON lines sorted by capsule_id
v0.2/tool_drift/leaves.json	217,679	06f5e6aca407f1f1947d1815527b76d5fbc5723768ce66962fc37c8fc4e9c99a	the batch's Merkle leaves (capsule ids)
v0.2/tool_drift/record.json	3,184	a7a13dab161631d0557726fd64c0dee82bd0b95cb54e2749d96aaddc93fef473	the batch record: adapter, states, Merkle root, capsule file hashes
v0.2/tool_drift/record.json.ots	635	d1ef2d355459afae33bed898cfd4576c0da1362cd15ec9714e9958c6275456c6	OpenTimestamps proof
v0.2/tool_drift/record.signed.json	1,564	de12c6b4aa1e785ec5b1a3c7ed55f23eb385f126d7ae91b851a4607b43ec5147	Ed25519 signature over a payload pinning record.json, the capsule file and the Merkle root

data/capsules.parquet has one row per capsule (the verbatim canonical line is in capsule_json); data/batches.parquet has one row per batch. verify.py re-derives both from the verbatim files.

Timestamps

• v0.2/a2a_card/record.json.ots commits to the sha256 of v0.2/a2a_card/record.json; its state is pending (3 calendar commitments, no Bitcoin block-header attestation in these bytes yet). A pending proof dates nothing until a block attests it.
• v0.2/contract_parity/record.json.ots commits to the sha256 of v0.2/contract_parity/record.json; its state is pending (3 calendar commitments, no Bitcoin block-header attestation in these bytes yet). A pending proof dates nothing until a block attests it.
• v0.2/cross_ledger/record.json.ots commits to the sha256 of v0.2/cross_ledger/record.json; its state is pending (3 calendar commitments, no Bitcoin block-header attestation in these bytes yet). A pending proof dates nothing until a block attests it.
• v0.2/index.json.ots commits to the sha256 of v0.2/index.json and carries a Bitcoin block-header attestation (confirmed in Bitcoin block 968674), plus 3 calendar attestations that are still pending and do not affect it.
• v0.2/mill_cross_runtime-5ae00c1f4c2e/record.json.ots commits to the sha256 of v0.2/mill_cross_runtime-5ae00c1f4c2e/record.json; its state is pending (3 calendar commitments, no Bitcoin block-header attestation in these bytes yet). A pending proof dates nothing until a block attests it.
• v0.2/mill_cross_runtime-78226433e9e4/record.json.ots commits to the sha256 of v0.2/mill_cross_runtime-78226433e9e4/record.json; its state is pending (3 calendar commitments, no Bitcoin block-header attestation in these bytes yet). A pending proof dates nothing until a block attests it.
• v0.2/public_signals/record.json.ots commits to the sha256 of v0.2/public_signals/record.json; its state is pending (3 calendar commitments, no Bitcoin block-header attestation in these bytes yet). A pending proof dates nothing until a block attests it.
• v0.2/publication/2026-09-26-erratum.json.ots commits to the sha256 of v0.2/publication/2026-09-26-erratum.json; its state is pending (3 calendar commitments, no Bitcoin block-header attestation in these bytes yet). A pending proof dates nothing until a block attests it.
• v0.2/publication/2026-09-26.json.ots commits to the sha256 of v0.2/publication/2026-09-26.json; its state is pending (3 calendar commitments, no Bitcoin block-header attestation in these bytes yet). A pending proof dates nothing until a block attests it.
• v0.2/self_parity/record.json.ots commits to the sha256 of v0.2/self_parity/record.json; its state is pending (3 calendar commitments, no Bitcoin block-header attestation in these bytes yet). A pending proof dates nothing until a block attests it.
• v0.2/tool_drift/record.json.ots commits to the sha256 of v0.2/tool_drift/record.json; its state is pending (3 calendar commitments, no Bitcoin block-header attestation in these bytes yet). A pending proof dates nothing until a block attests it.

v0.2/anchors.json records the producer's check of the index proof against the Bitcoin block header. Check any proof yourself with ots verify <file>.ots.

How to verify

pip install cryptography pyarrow
python3 verify.py

verify.py checks, for every batch: record.json against the signed payload; capsules.jsonl.gz and its decompressed bytes against record.json; that every capsule line is canonical JSON and its capsule_id is the sha256 of the canonical capsule without capsule_id; the RFC 6962 root over the sorted ids; the Ed25519 signature with a tamper control. Then the index against every batch, the index root, the derived tables and manifest.jsonl.

# Signature check in a few lines. did.json refuses the default Python User-Agent, so this names one.
import json, hashlib, base64, urllib.request
from cryptography.hazmat.primitives.asymmetric import ed25519
req = urllib.request.Request("https://csoai.org/.well-known/did.json",
                             headers={"User-Agent": "csoai-dataset-verify/1.0 (+https://huggingface.co/datasets/csoai)"})
did = json.load(urllib.request.urlopen(req, timeout=30))
x = [m for m in did["verificationMethod"] if m["id"].endswith("#board-attestation-1")][0]["publicKeyJwk"]["x"]
key = ed25519.Ed25519PublicKey.from_public_bytes(base64.urlsafe_b64decode(x + "=="))
for f in ["v0.2/a2a_card/record.signed.json", "v0.2/contract_parity/record.signed.json", "v0.2/cross_ledger/record.signed.json", "v0.2/index.signed.json", "v0.2/mill_cross_runtime-5ae00c1f4c2e/record.signed.json", "v0.2/mill_cross_runtime-78226433e9e4/record.signed.json", "v0.2/public_signals/record.signed.json", "v0.2/publication/2026-09-26-erratum.signed.json", "v0.2/publication/2026-09-26.signed.json", "v0.2/self_parity/record.signed.json", "v0.2/tool_drift/record.signed.json"]:
    s = json.load(open(f))
    c = json.dumps(s["payload"], sort_keys=True, separators=(",", ":"), ensure_ascii=False).encode()
    assert hashlib.sha256(c).hexdigest() == s["signature"]["payload_sha256"]
    key.verify(bytes.fromhex(s["signature"]["sig_ed25519"]), c)   # raises if the bytes were altered
    print("VERIFIES", f)

Signed by did:web:csoai.org#board-attestation-1. The signature proves who signed these bytes; it does not prove any claim beyond what the capsules' own instruments measured.

Objections, contact and corrections

Contact, corrections and objections (including a request to re-check or withdraw a specific row): nicholas@csoai.org, or the "Object or opt out" route at https://councilof.ai/census/. A correction is published as a new, linked version and logged in the signed corrections ledger at https://councilof.ai/api/corrections; signed files are never edited in place. CSOAI Ltd (company no. 16939677, England and Wales) is the accountable publisher.

How to cite

CSOAI Ltd (Council of AI). Signed measurement capsules v0.2 (2026-09-26 index). 2026. Hugging Face dataset csoai/measurement-capsules. https://huggingface.co/datasets/csoai/measurement-capsules

@misc{csoai_measurement_capsules_v0_2,
  title        = {Signed measurement capsules v0.2 (2026-09-26 index)},
  author       = {{CSOAI Ltd}},
  year         = {2026},
  howpublished = {Hugging Face dataset, https://huggingface.co/datasets/csoai/measurement-capsules},
  note         = {Corrections: https://councilof.ai/api/corrections}
}

Licence: CC-BY-4.0. Attribute Council of AI, CSOAI Ltd (16939677), https://councilof.ai.

Corrections and verification

• Corrections ledger (signed): https://councilof.ai/api/corrections. Corrections to CSOAI's published records are logged there with what changed and when.
• Verify a signed record yourself, free and without an account: https://councilof.ai/gspc-verify/ (step by step: https://councilof.ai/signed/HOW-TO-VERIFY.md).
• Conformance kit for signed-receipts/v1, with test vectors for implementers: https://councilof.ai/spec/signed-receipts/v1/conformance/