TYPE 0x0501 · ANCHOR FAMILY
ANCHOR
Generic data anchor. Validates at least one typed parameter is present. Used to commit arbitrary structured data on-chain for attestations, timestamping, and data anchoring.
Anchor InvertibleLadder Diagram
Fields
| Field | Data Type | Size | Side | Description |
|---|---|---|---|---|
| anchor_id | NUMERIC | 1-4 B | Conditions | Application-defined anchor identifier. The implicit layout (ANCHOR_CONDITIONS = {1, [NUMERIC]}) accepts exactly one NUMERIC; anything else is rejected at deserialization. The evaluator only confirms the field is non-empty — the value itself is opaque to consensus. |
No witness fields required. PubkeyCountForBlock = 0. ANCHOR is a marker block: consensus only checks "fields present"; the application defines what anchor_id means.
Wire Format Breakdown
0x0501
0
1
NUMERIC · 3-6B
Conditions ≈ 7-10 bytes
0x0501
0
0
Witness = 4 bytes (empty block)
Total
≈ 11-14 bytes
Evaluation Logic
1.Inspect
block.fields. If the vector is empty → ERROR2.Otherwise → SATISFIED. The evaluator does not parse
anchor_id or check its value — deserialization already enforced the implicit layout (exactly 1 NUMERIC).Return Values
| Condition | Result |
|---|---|
| No fields present (empty conditions) | ERROR |
| At least one typed field present | SATISFIED |
JSON Wire Format
Conditions (generic data anchor with hash + timestamp)
{
"type": "ANCHOR",
"inverted": false,
"fields": [
{ "type": "NUMERIC", "value": 1709856000 }
]
}For richer attestations (document hash + timestamp + signer), compose ANCHOR with TAGGED_HASH and SIG blocks; ANCHOR alone is intentionally a single-NUMERIC marker.
Use Cases
On-chain Attestations
Commit structured data on-chain as a tamper-proof record. Any combination of field types can be anchored, creating verifiable attestations without requiring custom block types.
Data Anchoring
Hash a document, dataset, or state snapshot and anchor it in a transaction. The blockchain provides an immutable timestamp proof that the data existed at a specific block height.
Timestamping
Commit a hash with a numeric timestamp field to create a provable record of when data was committed. Useful for intellectual property proofs, audit trails, and regulatory compliance.