Verification

Verify the feed yourself. Every entry is signed, every entry names the one before it, and every page carries a freshly signed statement of the newest entry. The rules are exact enough to write your own verifier, and three reference verifiers pass all 125 published test vectors.

On this page

A signed entry
The checks
The kit
Run it
A clean result
Filtered reads and key revocation

A signed entry

record_hash: SHA-256 of the entry's canonical text, lowercase hex.
signature: Ed25519 signature over the 64-character hash string, hex.
public_key_id: the key in public-key.json that made it. Retired keys stay in the file so old entries keep verifying.
prev_seq and prev_hash: the seq and record_hash of the entry before.
feed_head, on every page: {"type":"feed_head","seq":N,"record_hash":"...","signed_at":"..."}, signed at the time of the request.

The checks

Check	What it establishes
Hash and signature of each entry	The text is exactly what was signed, by a key in the key file.
`seq` and chain	Entries are in order and each names the one before it, so nothing was changed, inserted or removed in the middle.
Publications	Revisions follow one another: `revision` rises by one and `supersedes_seq` names the previous entry.
Status entries	Standing changes are well formed, and the set of revoked entries is derived from them.
Signed head	The head is genuine and agrees with the entries; if the last page ends before the head's `seq`, entries were dropped from the end.
Key revocation	Entries signed by a revoked key are trusted only up to the last trusted entry named in a signed notice.

Section 4 of the rules states exactly what a clean result does and does not establish, including how to compare heads across AI Platforms.

The kit

Everything is at https://feed.aigistry.com/verify/, with a SHA-256 checksum for every file.

VERIFICATION.md: the rules, version 1.2.
verify_feed.py (Python, needs cryptography), verify-record.php.txt (PHP, needs sodium; save as verify-record.php) and verify-feed.mjs (Node 18 or later).
vectors/: 125 test vectors, one JSON file each, with expected results: valid feeds, tampering, omissions, truncation, status entries, revoked keys. A verifier you write should pass every one.

Run it

python3 verify_feed.py --keys public-key.json page1.json page2.json
php verify-record.php --keys public-key.json page1.json page2.json
node verify-feed.mjs --keys public-key.json page1.json page2.json
python3 verify_feed.py --vectors vectors   # the folder of vector files

Options: --prev-seq N --prev-hash HEX (anchor: the last entry you verified last time), --filtered, --json. Exit status: 0 nothing wrong was found, 1 problems were found, 2 the input could not be read. Pass pages in order. Keep reading while a page's has_more is true, using next_after as the next after.

A clean result

Every entry was signed by a key in the public key file, and its text is exactly what was signed.
The entries are in order and each names the one before it.
If the last page carried a signed head, nothing was cut from the end.
The verifier also works out which publications are revoked from the signed status entries, so you can compare it with the lookup route.

Filtered reads and key revocation

A read filtered to one authority record, GovTech Provider or government returns the matching entries unchanged and in order. Tell the verifier the read was filtered (--filtered); it never takes that from the unsigned filter member. A filtered read authenticates every entry it returns; read the whole feed without a filter when completeness matters. If a signing key is ever revoked, public-key.json carries a signed notice with the last trusted entry, and the verifiers apply it.

Entry text is authenticated, not safe: title and body are written by GovTech Providers, so treat them as untrusted data.