Spec v1.0.0

The export format is public. On purpose.

Every AssetDNA organisation can download its complete operating record as one open JSON file — assetdna.export.v1 — and anyone can verify that file offline, without AssetDNA existing. This page and the machine-readable schema below are the whole contract. If we ever disappeared, raised prices, or misbehaved, your record walks out the door intact and provable. That is the point.

JSON Schema →Verify an export in your browser →The connector spec (what goes in) →

The integrity model in one paragraph

Every change to the record is an event in an append-only chain. Each event's hash commits to the previous event's hash, so history can't be rewritten without breaking every hash after the edit. Head hashes are periodically anchored with an independent RFC 3161 timestamp authority, so the history provably existed — even we can't back-date it. Documents are bound in by SHA-256 fingerprint. The export carries all of it.

Hash rule

hash    = sha256( prevHash | type | payload | at(ISO) | propertyId )
genesis = "0000000000000000000000000000000000000000000000000000000000000000"

payload is hashed VERBATIM as the JSON string in the file — do not parse
and re-serialise it. at is hashed in ISO-8601 form. A null propertyId
hashes as the empty string. Field separator is "|".

Verification recipe

Sort events by seq ascending; confirm seq is contiguous from 1.
Start with prev = genesis. For each event: confirm prevHash === prev, re-derive the hash with the rule above, confirm it equals the event's hash, then set prev to it.
Confirm the final prev equals integrity.headHash.
Optionally, verify each anchor's RFC 3161 token (downloadable per-anchor) against its headHash with the authority's public certificate — proof of existence at the signed time, independent of AssetDNA.
For any document you hold the bytes of, confirm its SHA-256 equals the record's sha256.

Steps 1–3 run in any language in ~20 lines with a SHA-256 primitive — or paste the file into the in-browser verifier, which does exactly this with Web Crypto and no upload.

Field reference

Field	Type	Meaning
format	"assetdna.export.v1"	Format discriminator. Version-suffixed; breaking changes mint a new value.
exportedAt	string (ISO-8601)	When this file was produced.
org	object	name, slug, reportingCurrency (ISO 4217) of the exporting organisation.
integrity	object	The exporter's own audit at export time: chainVerified, events (count), genesis, headHash, hashRule. Recompute it yourself — never take this object on trust.
properties	object[]	The operating record: units, leases, valuations, meter readings, incidents, compliance. Convenience data — the events chain is the authoritative history.
events	object[]	The full hash chain, ascending contiguous seq from 1. Each event: seq, type, payload (a JSON string — hashed verbatim), at, actor, source, propertyId, prevHash, hash.
anchors	object[]	External RFC 3161 timestamps over head hashes: atSeq, headHash, tsaProvider, tsaTime. Independent third-party proof the history existed by a point in time.
documents	object[]	Document metadata + SHA-256 fingerprints: kind, filename, sha256, sizeBytes, uploadedBy, uploadedAt. Raw bytes download separately; the hash binds them to the record.

The strict contract is the chain-critical structure (integrity, events, anchors, documents); properties is deliberately open and may grow fields without a version bump. The authoritative machine-readable definition is the JSON Schema (draft 2020-12).

Versioning promise

assetdna.export.v1 is frozen: fields may be added, never removed or changed in meaning, and the hash rule never changes within v1. A breaking change mints assetdna.export.v2 alongside — v1 files stay verifiable forever, because a proof that expires is not a proof.