omh-shim

Convert wearable health data from vendor schemas to Open mHealth schemas.

Status

v1.0 — initial public release. Public API is stable; converter coverage will continue to expand.

Install

pip install git+https://github.com/jupyterhealth/omh-shim.git@v1.0.1

Usage

Timestamp-based data types (one reading at a known instant):

from omh_shim import convert

omh_record = convert(
    source="ow_normalized",
    data_type="heart_rate",
    sample={
        "timestamp": "2026-04-09T08:30:00+00:00",
        "type": "heart_rate",
        "value": 72,
        "unit": "bpm",
        "source": {"source_name": "Oura Ring", "device_model": "Oura Gen 3"},
    },
)

Daily data types (step_count, physical_activity, sleep_duration, oxygen_saturation) aggregate over a calendar day, so they REQUIRE an explicit timezone so the day boundaries reflect the user's local day rather than silently assuming UTC:

from datetime import UTC
from zoneinfo import ZoneInfo

# UTC-anchored upstream data
convert(
    source="oura_raw",
    data_type="step_count",
    sample={"day": "2026-04-09", "steps": 8432},
    tz=UTC,
)

# User's local timezone
convert(
    source="oura_raw",
    data_type="step_count",
    sample={"day": "2026-04-09", "steps": 8432},
    tz=ZoneInfo("America/Los_Angeles"),
)

Every conversion returns the full IEEE 1752.1 data-point envelope — {"header": ..., "body": ...} — with UUID, schema_id components, creation timestamp, modality, and external_datasheets auto-populated from the sample's source metadata (a nested source dict, or the device implied by source for raw feeds like oura_raw):

convert(
    source="oura_raw",
    data_type="heart_rate",
    sample={"bpm": 72, "source": "rest", "timestamp": "2026-04-09T03:15:00+00:00"},
)
# Returns:
# {
#   "header": {
#     "uuid": "...",
#     "schema_id": {"namespace": "omh", "name": "heart-rate", "version": "2.0"},
#     "source_creation_date_time": "...",
#     "modality": "sensed",
#     "external_datasheets": [{"datasheet_type": "manufacturer", "datasheet_reference": "Oura Ring"}]
#   },
#   "body": {
#     "heart_rate": {"value": 72.0, "unit": "beats/min"},
#     "effective_time_frame": {"date_time": "2026-04-09T03:15:00Z"}
#   }
# }

convert raises ConversionError for unknown (source, data_type) pairs, invalid sample shapes, naive (timezone-less) datetimes, or a missing tz for daily data types. It raises ValidationError if the converter output fails schema validation.

Supported sources and data types

Note: heart_rate_variability targets the local placeholder schema local:heart-rate-variability:1.0 (Open mHealth has not published a canonical HRV schema as of 2026-04). The local: namespace is deliberate — downstream consumers should not assume OMH-standard interoperability for HRV records.

Served schemas without a converter

omh-shim also vendors clinical OMH body schemas that have no convert() converter: blood pressure, body temperature, body weight, forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), respiratory rate, and RR interval. They exist so consumers can serve and validate OMH bodies offline from a single pinned source:

from omh_shim import known_ids, load_schema

"omh:blood-pressure:4.0" in known_ids()    # True
schema = load_schema("omh:blood-pressure:4.0")  # vendored JSON schema, all $refs resolvable offline

These are tracked as SERVED_NO_CONVERTER in tests/test_schema_coverage.py (the authoritative list) and refreshed alongside the converter schemas by tools/refresh_schemas.py.

Adding a new source

See docs/adding-a-source.md for a step-by-step guide to adding a new device source (converter functions, test fixtures, documentation).

Mapping references

• docs/mappings/oura_raw.md — Oura Ring v2 API → OMH (body fields)
• docs/mappings/ow_normalized.md — Open Wearables normalized API → OMH (body fields)
• docs/mappings/ieee-1752-header.md — IEEE 1752.1 data-point header envelope

Credits

omh_shim/sources/oura_raw.py ports converter mapping logic with permission from dicristea/oura-clinical-workbench. See AUTHORS.md.

License

MIT. See LICENSE.