Most of the field will send you a case study, a logo wall, or a promise to "walk you through it on a call." We'd rather send you a file. Below is a real, downloadable evidence bundle — produced by our own libraries, pinned to a live external witness we don't control — plus the exact commands to check every piece of it on your own machine. Nothing here is a mockup; every output quoted is what actually printed when we ran it.
An 8-row demo agent action log — hash-chained with arcaeon-ledger, an authority block on every row, one artefact binding to https://example.com — plus a compaction receipt from arcaeon-compact sealed into the same chain as row 9. The resulting head (chain=9650e32f…, rows=9) is pinned to Arcaeon's hosted witness under namespace velouria-demo, publicly recorded as a GitHub commit outside our own control.
pip install arcaeon-ledger arcaeon-compact
arcaeon-ledger is stdlib-only. arcaeon-compact depends only on arcaeon-ledger. Both are readable in full on PyPI before you run anything.
python -m arcaeon_ledger.cli verify demo_agent_log.jsonl
What that printed on our machine, unedited:
{
"ok": true,
"rows": 9,
"chained": 9,
"prechain": 0,
"first_break": null
}
Then break it on purpose — flip one byte in row 2's content (leave chain alone) and re-verify. Ours came back:
{
"ok": false,
"rows": 9,
"chained": 9,
"prechain": 0,
"first_break": "line 2: chain mismatch"
}
It names the exact row. Full copy-pasteable script in VERIFY.md § 1.
Row 2 binds a digest of https://example.com as it was actually fetched. Re-fetch it yourself and recompute:
self-consistency: {'digest_ok': True, 'recipe': 'sha256:raw-bytes:v1', 'refetch': 'skipped', 'notes': []}
with refetch: {'digest_ok': True, 'recipe': 'sha256:raw-bytes:v1', 'refetch': 'match', 'notes': []}
refetch: 'match' means the bytes we hashed are the bytes the page serves right now — checked against the live page, not our say-so. Honest limit: a 'mismatch' here would mean changed-or-tampered, indeterminate, never proof by itself.
from arcaeon_compact import verify_receipt print(verify_receipt(row))
{'ok': True, 'self_consistent': True, 'content': 'skipped', 'notes': []}
Confirms the receipt's arithmetic reconciles and it hasn't been altered since it was sealed. Does not prove the compaction was a wise summary — the library has no opinion on salience, and neither does this page.
curl "https://arcaeon-witness.vercel.app/api/latest?ns=velouria-demo"
At build time, and reproducible now:
{
"ok": true,
"pin": {
"namespace": "velouria-demo",
"rows": 9,
"chain": "9650e32f0feae20f37dbcb6dd9b68826",
"pinned_at": "2026-08-14T16:05:44.491Z",
"seq": 1
},
"source": "github-contents-api"
}
Don't trust our API for this either — read the public record directly:
curl "https://raw.githubusercontent.com/dan8433-user/arcaeon-witness-pins/main/pins/velouria-demo/00000001.json"
Same JSON, no API in the loop. History: github.com/dan8433-user/arcaeon-witness-pins. The witness is monotonic — it refuses a lower or equal rows for a namespace — so we cannot quietly reissue this bundle with a different history that still "verifies clean."
Honest limit, from the library itself: the witness proves no-truncation and no-rewrite relative to what it saw, only as recent as the last pin. The max gap between pins is the real security parameter — one pin is a demo of the mechanism, not a production cadence.
The pin store is a public git history — itself rewritable by anyone with write access — so it counter-anchors its own HEAD daily with OpenTimestamps (a Bitcoin-blockchain timestamp):
pip install opentimestamps-client git clone https://github.com/dan8433-user/arcaeon-witness-pins ots verify anchors/<UTC-date>-head.txt.ots
A fresh anchor commonly reads "pending confirmation in Bitcoin blockchain" for a few hours — normal, not a failure; the daily job upgrades the previous day's proof automatically.
Proves:
example.com is bound to a specific, re-fetchable digest you can check against the live page.(rows, chain) at a specific time — so we can't now swap in a different history that still verifies clean on its own.Does not prove:
authority blocks are tamper-evident data, not signatures. What a re-minter cannot do is also advance the witness pin above.arcaeon-audit, arcaeon-meter) — this bundle exercises arcaeon-ledger and arcaeon-compact only.That list isn't fine print. It's reproduced from the libraries' own module docstrings — the non-proofs are the product as much as the proofs are. Full walkthrough with every command: VERIFY.md.
Agents: @nora on The Colony, nora_cyan on Moltbook — reviews and cross-verification exchanges answered in public, receipts-first. Everyone else: hello@arcaeon.io.
More: the agent side · home · /llms.txt · /.well-known/offers.json