Heimdall Power API Changelog

Facility voltages now included in asset response

Mon, 18 May 2026 00:00:00 GMT

The GET /assets/v1/assets response now includes nominal_voltage (always present) and operational_voltage (optional) on each facility. Both are phase-to-phase voltages in volts. These values feed the apparent-power calculation on the capacity-monitoring circuit-rating endpoint.

Circuit rating can now be returned as apparent power

Mon, 18 May 2026 00:00:00 GMT

GET /capacity_monitoring/v1/facilities/{facility_id}/circuit_ratings/latest now accepts an optional metric query parameter. Use metric=current (default) to receive the rating in amperes, or metric=apparent_power to receive it in MVA, computed as S = sqrt(3) * V * I / 1,000,000. The line's operational voltage is used when configured and positive; otherwise the nominal voltage is used. Both voltages are exposed on the facility in the GET /assets/v1/assets response so you can verify which value the calculation used.

Historical circuit ratings endpoint added

Tue, 12 May 2026 00:00:00 GMT

Added GET /capacity_monitoring/v1/facilities/{facility_id}/circuit_ratings, which returns a time series of circuit ratings for a facility over a requested period. Use this endpoint to retrieve historical circuit rating data rather than just the latest value.

Historical conductor temperatures endpoint added

Tue, 12 May 2026 00:00:00 GMT

Added GET /grid_insights/v1/lines/{line_id}/conductor_temperatures, which returns a time series of conductor temperature measurements for a line over a requested period. Use this endpoint to retrieve historical conductor temperature data rather than just the latest value.

DLR response now includes the span with lowest ampacity

Tue, 05 May 2026 00:00:00 GMT

The GET /capacity_monitoring/v1/lines/{line_id}/heimdall_dlrs/latest response now includes at_span_id, a UUID identifying the specific span on the line where the lowest ampacity was calculated. This lets you pinpoint which part of the line is the limiting factor for the current DLR value.

Facility components now included in asset response

Wed, 29 Apr 2026 00:00:00 GMT

The GET /assets/v1/assets response now includes facility components. This allows grid owners to map facility component IDs to component names.

Historical line currents endpoint added

Wed, 29 Apr 2026 00:00:00 GMT

Added GET /grid_insights/v1/lines/{line_id}/currents, which returns a time series of current measurements for a line over a requested period. Use this endpoint to retrieve historical current data rather than just the latest value.

DLR response now indicates fallback values

Thu, 23 Apr 2026 00:00:00 GMT

The GET /capacity_monitoring/v1/lines/{line_id}/heimdall_dlrs/latest response now includes an is_fallback field. When true, the DLR value is a fallback rather than a live calculation — this applies to grid owners who have opted in to the fallback feature. Integrations that display or act on DLR values should account for this flag.

Sag and clearance response includes extremum values

Thu, 16 Apr 2026 00:00:00 GMT

The GET /grid_insights/v1/lines/{line_id}/sag_and_clearance/latest response now includes line-level max_sag and min_clearance values for the current aggregation window, together with per-span sag and clearance details. This makes it easier to identify the highest sag and lowest clearance on a line without polling repeatedly.