Product Identity Hash
A Product Identity Hash is a deterministic SHA-256 checksum calculated from a category's active identity policy and the product values that the policy marks as identity components. Actualog uses it for exact duplicate prevention, import matching, and group-of-variants assignment.
It is not an AI embedding, not a similarity score, and not a manually entered product identifier.
What is included
The group identity payload contains:
- identity policy ID and version;
- identity mode;
- category ID;
- identity attributes assigned to the Group level;
- for Brand-defined identity, Brand ID and Brand Owner company ID.
For Specification-defined identity, brand and Brand Owner are not included.
Variant identity attributes are stored separately. Their configured order identifies the variant axes, while the checksum is produced from a stable normalized representation.
Three checksums
Actualog stores identity keys in ProductIdentityKeys.
| Checksum | Meaning |
|---|---|
| Group checksum | Identifies the standalone product or the shared identity of a group of variants. |
| Variant checksum | Identifies one combination of variant-axis values inside the group. For a non-variant product it is the hash of an empty variant list. |
| Product checksum | Identifies the concrete product. For a variant it is calculated from the Group checksum plus Variant checksum; for a standalone product it equals the Group checksum. |
An active identity-key record also preserves the component JSON, category, effective-template version, identity-policy version, product, and optional group of variants. This makes the checksum explainable and version-aware.
Normalization before hashing
The calculation produces a stable JSON representation before SHA-256 is applied.
- attributes are ordered by Attribute ID and type;
- text is trimmed, repeated whitespace is collapsed, and text is converted to uppercase;
- numeric values use invariant round-trip formatting;
- Boolean values remain Boolean;
- list values and reference-item IDs are de-duplicated and sorted;
- identity rules are ordered deterministically.
The hash function does not guess synonyms and does not perform semantic matching. Identity-relevant values must already be represented correctly in Actualog's structured product data.
Missing, stale, and conflicting identity
- Missing identity means a required identity policy component is absent. Actualog does not create a usable identity key.
- Stale means the saved identity no longer represents the current policy or inputs and must be recalculated.
- Conflict means multiple products produced the same Product checksum or another identity/grouping conflict requires repair.
- Complete means the active key can participate in matching and duplicate resolution.
When to recalculate identity
Use Recalculate identity after identity-relevant changes, including changes to:
- category identity policy;
- identity attributes;
- variant axes;
- brand or Brand Owner for Brand-defined identity;
- identity-relevant structured product values;
- effective-template identity rules.
Recalculate identity from Product Overview or Product Stewardship for the selected products. A category policy change can mark affected products Stale so they can be processed safely.
Why the hash is stored
The stored key makes exact identity lookup fast and lets Actualog enforce active uniqueness without recalculating every product during every search or import. The component JSON explains which values produced the hash, while policy and template references show which version of the rules was used.