HDF Schema Reference

The Heimdall Data Format (HDF) defines 7 JSON document types for security assessment data. Each schema is self-contained — all referenced types are embedded, no external fetches needed.

Document Types

HDF Results

Assessment results from running security checks against a target system.

• Version: v3.7.0
• $id: https://mitre.github.io/hdf-libs/schemas/hdf-results/v3.7.0

HDF Baseline

Security requirement definitions without results — the "what to check" document.

• Version: v3.7.0
• $id: https://mitre.github.io/hdf-libs/schemas/hdf-baseline/v3.7.0

HDF System

System authorization boundary, components, data flows, and control designations.

• Version: v3.7.0
• $id: https://mitre.github.io/hdf-libs/schemas/hdf-system/v3.7.0

HDF Plan

Assessment plan defining what baselines to run against which components.

• Version: v3.7.0
• $id: https://mitre.github.io/hdf-libs/schemas/hdf-plan/v3.7.0

HDF Amendments

Waivers, attestations, POA&Ms, and other status overrides applied to findings.

• Version: v3.7.0
• $id: https://mitre.github.io/hdf-libs/schemas/hdf-amendments/v3.7.0

HDF Evidence Package

Bundle of references to all HDF documents for a complete assessment record.

• Version: v3.7.0
• $id: https://mitre.github.io/hdf-libs/schemas/hdf-evidence-package/v3.7.0

HDF Comparison

Differential analysis of two or more assessment results.

• Version: v3.7.0
• $id: https://mitre.github.io/hdf-libs/schemas/hdf-comparison/v3.7.0

HDF Requirement Change Event

A single continuous-monitoring wire event: one requirement's effective posture changed on one system component.

• Version: v3.7.0
• $id: https://mitre.github.io/hdf-libs/schemas/hdf-requirement-change-event/v3.7.0

Downloads

Schema	Version	Download
HDF Results	v3.7.0	hdf-results.schema.json
HDF Baseline	v3.7.0	hdf-baseline.schema.json
HDF System	v3.7.0	hdf-system.schema.json
HDF Plan	v3.7.0	hdf-plan.schema.json
HDF Amendments	v3.7.0	hdf-amendments.schema.json
HDF Evidence Package	v3.7.0	hdf-evidence-package.schema.json
HDF Comparison	v3.7.0	hdf-comparison.schema.json
HDF Requirement Change Event	v3.7.0	hdf-requirement-change-event.schema.json