HHS §1557 — capability brief.
Planisphere's evidence record answers HHS §1557's evidentiary asks via the Astrolabe schema. The mapping is published, reproducible byte-for-byte on customer hardware, and re-verifiable by any third party with the same inputs.
Scope.
In scope. ACA non-discrimination in patient-care AI. Cite-anchor: HHS §1557.
Out of scope. Production data (no PHI, no PII, no student record, no privileged correspondence). Model weights. Customer's own analyses of the evidence record.
Boundary. Only sha-pinned, Merkle-rooted derived metadata crosses; model state never does. U.S. provisional patent No. 64/073,668 covers the property.
Evidence.
Every measurement against HHS §1557 lands in a signed evidence record: each artifact carries its own SHA-256, the artifacts chain into a Merkle root, and the engine version is pinned alongside. Internal or external compliance recomputes the root and checks the record — without the model state ever crossing the boundary.
Limitations.
Planisphere measures behaviour, not capability. The evidence record says this is what your fleet did against the probe set; it does not say this is what your fleet will do under adversarial pressure. Adversarial coverage is a scope expansion that adds a probe family; the engine and the record shape do not change.
Reproducibility requires the inputs to be preserved. The record pins the inputs by SHA; it does not host them.
Reproducibility & compliance check.
Open the evidence check. Drop ATTESTATION.json and the named artifacts. The browser recomputes each per-artifact SHA-256 and the chained Merkle root via Web Crypto. Files do not leave the tab.
For a synthetic 3-subject record, see how a record is checked: one click checks an intact record; one click checks a tampered record and names the failing file.
Cite.
Planisphere Corp., HHS §1557 — capability brief, v0.1, https://www.planisphere.ooo/corpus/hhs-1557/brief. Methodology preprint: 10.5281/zenodo.20372606.