generated: '2026-09-05'
method: searched
source: https://support.75f.io/hc/en-us/articles/6477813004691-Haystack-Filters-Queries
note: >-
  75F publishes no OpenAPI, so this entity graph is not derived from schema $refs. It is read from the
  provider's own documentation — the Haystack ref tags that appear verbatim in its published request
  filters and response grids (siteRef, floorRef, roomRef, equipRef, tunerGroup) plus the response column
  sets reproduced in the Read and PointWrite articles. Only relationships 75F's own examples show are
  recorded; the wider Project Haystack ontology is not imported.
standard: Project Haystack 3.0
identifier_scheme:
  request_form: '@<uuid>'
  response_form: 'r:<uuid>'
  detail: >-
    Entities are UUID Refs. In a request filter or an id list they are written with a leading @; in a
    JSON response grid the same id is serialized as the string "r:<uuid>". Marker tags serialize as "m:".
    There are no type-prefixed ids — a Ref does not tell a client what kind of entity it points at, so
    entity type must be read from the marker tags on the row.
entities:
- name: site
  markers: [site]
  description: A building. The top of the containment hierarchy and the unit of API authorization.
- name: floor
  markers: [floor]
  description: A floor within a site.
- name: room
  markers: [room]
  description: A room within a floor.
- name: zone
  markers: [zone]
  description: A conditioned zone; the unit that special schedules and setpoints are applied to.
- name: equip
  markers: [equip]
  description: A piece of equipment — VAV terminal, CCU system, chiller plant, air handler.
- name: point
  markers: [point]
  description: >-
    A single datum on an equipment. Carries kind, unit and tz, and the marker tags that classify it
    (sensor, sp, cmd, cur, his, writable, temp, co2, air, damper, config).
- name: specialSchedule
  markers: []
  description: >-
    An exception-based schedule on a zone or building, addressed by scheduleId on the v2 REST surface
    rather than by a Haystack Ref. It is the one documented 75F entity that is not a Haystack record.
relationships:
- {from: floor, to: site, type: belongs_to, via: siteRef}
- {from: room, to: floor, type: belongs_to, via: floorRef}
- {from: zone, to: room, type: belongs_to, via: roomRef}
- {from: equip, to: site, type: belongs_to, via: siteRef}
- {from: point, to: equip, type: belongs_to, via: equipRef}
- {from: point, to: room, type: belongs_to, via: roomRef}
- {from: point, to: floor, type: belongs_to, via: floorRef}
- {from: point, to: site, type: belongs_to, via: siteRef}
- {from: site, to: point, type: has_many, via: siteRef}
- {from: equip, to: point, type: has_many, via: equipRef}
- {from: point, to: tuner, type: belongs_to, via: tunerGroup}
- {from: specialSchedule, to: zone, type: belongs_to, via: zoneId}
point_attributes:
  observed_columns:
  - id
  - dis
  - kind
  - unit
  - tz
  - curVal
  - cur
  - his
  - hisInterpolate
  - point
  - sensor
  - sp
  - writable
  - minVal
  - maxVal
  - incrementVal
  - threshold
  - group
  - series
  - parallel
  - logical
  - data
  source: >-
    Column sets reproduced verbatim in the 75F Read API and PointWrite API response examples.
  note: >-
    `writable` is the load-bearing tag for any agent or integration: only points carrying it can be
    written, and 75F states that relays, analog outputs and direct physical components are not
    addressable at all.
write_semantics:
  model: Haystack priority array
  detail: >-
    A pointWrite lands at a numbered priority level and the response returns the resulting array
    (duration, level, val, who) rather than an empty grid, so a caller can see which level it now
    occupies and who else holds a higher one. The `who` column identifies the writer — a CCU writes as
    "ccu_@<uuid>", an API caller as "api_<name>".
  source: https://support.75f.io/hc/en-us/articles/6012128424851-PointWrite-API
history:
  detail: >-
    Points tagged `his` are historized. hisReadMany returns timestamp/value pairs with grid metadata
    carrying id, hisStart and hisEnd; ranges are inclusive of the start and exclusive of the end and are
    evaluated in the point's own configured timezone, converting if the caller names a different one.
  source: https://support.75f.io/hc/en-us/articles/5460179115923-HisReadMany-API