Home / Compare / Heartwood Memory
Heartwood proves who could see it. Lians proves when you knew it.
Heartwood centers access policy and signed provenance. Lians centers bitemporal facts and historical reconstruction.
Credit first
Heartwood has a real governance thesis.
Heartwood enforces policy before ranking, signs provenance, isolates tenants, chains its audit log, and follows erasure into derived embeddings.
These are meaningful controls; the products solve different primary problems.
Documented product surfaces, reviewed July 17, 2026
Same risk class, different primary proof.
| Capability | Lians | Heartwood Memory |
|---|---|---|
| Primary guarantee | Knowledge state at time T | Policy-compliant, attributable recall |
| Temporal model | Valid time plus system time | Effective-time filtering documented |
| Historical API | recall_at and reconstruct | Public quickstart centers recall and explain_recall |
| Revision handling | Deterministic keyed supersession | Typed, governed memory records |
| Policy before ranking | Barrier and namespace controls | Core documented design |
| Provenance and audit | Tamper-evident audit and lineage | Signed provenance and hash-chained audit |
| Crypto-shred erasure | Key destruction with retained certificate | Per-subject key-destruction proof |
| Backtest lookahead check | backtest_check | Not listed in the public MCP quickstart |
| Current core license | Apache-2.0 | BSL 1.1 from 0.2.0; earlier releases remain MIT |
| Published SDK surfaces | Python, TypeScript, Java, C, and Go | Python core; governed TypeScript SDK listed as in development |
Decision guide
Choose the proof your system must produce.
Choose Heartwood when access policy and signed provenance are primary.
Choose Lians when historical knowledge state is primary.
For both needs, evaluate them as complementary control planes.
Sources