specification: API Commons Data Model
specificationVersion: '0.1'
provider: Appalachian Regional Commission
providerId: appalachian-regional-commission
generated: '2026-09-07'
method: derived
source: >-
  OPTIONS schema documents returned by https://www.arc.gov/wp-json/wp/v2/<type> and the
  /wp/v2/types + /wp/v2/taxonomies registries, plus the ArcGIS layer descriptors saved under
  openapi/_source/. All fetched live on 2026-09-07.
description: >-
  ARC's public data model is two disconnected graphs. On www.arc.gov, WordPress custom post types
  describe the institution — its programs, districts, staff, events and publications — and every
  one of them is joined to the others through shared taxonomies rather than foreign keys. On
  ArcGIS, flat feature layers carry the actual regional statistics, joined to each other only by
  the county FIPS code. Nothing links the two graphs: a report record on arc.gov does not reference
  the feature service that holds its data, and the feature services carry no back-reference to the
  report. FIPS and the states_counties taxonomy are the nearest thing to a common key, and they are
  not interchangeable.
entities:
  - name: Report
    surface: wordpress
    rest_base: report
    count_observed: 304
    description: Research reports, evaluations, chartbook chapters, fact sheets and infographics.
    fields: [id, date, date_gmt, modified, modified_gmt, slug, status, type, link, title, content, excerpt, featured_media, template, acf]
    relationships:
      - has_many: TaxonomyTerm
        via: global_type
      - has_many: TaxonomyTerm
        via: tax_year
      - has_many: TaxonomyTerm
        via: research_eval_maps_data_type
      - has_many: TaxonomyTerm
        via: fact_sheets_infographics_type
      - has_many: TaxonomyTerm
        via: fact_sheets_infographics_topic
      - has_many: TaxonomyTerm
        via: research_report_eval_topic
      - has_many: TaxonomyTerm
        via: investment_priority_topic
      - has_many: TaxonomyTerm
        via: states_counties
      - has_one: Media
        via: featured_media
  - name: Map
    surface: wordpress
    rest_base: map
    count_observed: 161
    description: Map records for the regional maps ARC publishes — economic status, poverty, income, population, county types, congressional districts.
    fields: [id, date, modified, slug, status, type, link, title, content, excerpt, template, acf]
    relationships:
      - has_many: TaxonomyTerm
        via: map_topic
      - has_many: TaxonomyTerm
        via: global_type
      - has_many: TaxonomyTerm
        via: tax_year
      - has_many: TaxonomyTerm
        via: research_eval_maps_data_type
      - has_many: TaxonomyTerm
        via: states_counties
    note: >-
      A Map record is metadata and an embed, not data. The features it renders live in the ARC
      Geospatial API; the join is editorial and is not expressed as a field.
  - name: Resource
    surface: wordpress
    rest_base: resource
    count_observed: 71
    description: Applicant and grantee resources — guides, forms, compliance material, funding-stage aids.
    relationships:
      - has_many: TaxonomyTerm
        via: grant_resources_funding_type
      - has_many: TaxonomyTerm
        via: grant_resources_resource_type
      - has_many: TaxonomyTerm
        via: grant_resources_funding_stage
      - has_many: TaxonomyTerm
        via: applicant_resources_funding_op
      - has_many: TaxonomyTerm
        via: applicant_resources_project_type
      - has_many: TaxonomyTerm
        via: applicant_resources_type
      - has_many: TaxonomyTerm
        via: grantee_resources_funding_op
      - has_many: TaxonomyTerm
        via: grantee_resources_project_type
      - has_many: TaxonomyTerm
        via: grantee_resources_resource_type
      - has_many: TaxonomyTerm
        via: state_resource_type
      - has_many: TaxonomyTerm
        via: investment_priority_topic
      - has_many: TaxonomyTerm
        via: states_counties
  - name: LocalDevelopmentDistrict
    surface: wordpress
    rest_base: ldd
    count_observed: 74
    description: >-
      The multi-county planning organizations — also called Area Development Districts, Councils of
      Governments or Regional Planning and Development Commissions — that deliver ARC investment.
    relationships:
      - has_many: TaxonomyTerm
        via: states_counties
    note: >-
      The same 74 districts are also published as geometry in the arc_local_development_districts
      feature service. The two are not linked by any identifier; matching them requires name or
      spatial reconciliation.
  - name: InvestmentPriority
    surface: wordpress
    rest_base: investment_priority
    count_observed: 9
    description: ARC's investment priorities, the top-level framing for every grant program.
    relationships:
      - has_many: TaxonomyTerm
        via: states_counties
      - referenced_by: [Report, Resource, Event, SuccessStory, Page]
        via: investment_priority_topic
        note: >-
          The join is a taxonomy term, not this post's id. investment_priority_topic carries 22
          terms while investment_priority carries 9 posts — they are near-parallel vocabularies,
          not a foreign-key pair, and should not be merged.
  - name: SuccessStory
    surface: wordpress
    rest_base: success_story
    count_observed: 17
    description: Investments in Action — funded projects profiled by ARC.
    relationships:
      - has_many: TaxonomyTerm
        via: [global_type, investment_priority_topic, states_counties]
  - name: Event
    surface: wordpress
    rest_base: event
    count_observed: 163
    relationships:
      - has_many: TaxonomyTerm
        via: [event_type, event_topic, event_host, month, tax_year, investment_priority_topic, states_counties]
  - name: Staff
    surface: wordpress
    rest_base: staff
    count_observed: 120
    description: ARC staff profiles and state-partner contacts.
    relationships:
      - has_many: TaxonomyTerm
        via: [staff_type, staff_topic, state_partner_role, states_counties]
  - name: Post
    surface: wordpress
    rest_base: posts
    count_observed: 204
    description: ARC newsroom items.
    relationships:
      - has_many: TaxonomyTerm
        via: [category, post_tag, global_type, tax_year, newsroom_topic, office_inspector_general_type, newsroom_types, states_counties, operational_guidance_type]
  - name: Page
    surface: wordpress
    rest_base: pages
    count_observed: 176
    relationships:
      - has_many: TaxonomyTerm
        via: [investment_priority_topic, states_counties]
      - belongs_to: Page
        via: parent
  - name: Media
    surface: wordpress
    rest_base: media
    count_observed: 6293
    description: The media library — the PDFs behind ARC's reports, plus images and infographics.
    relationships:
      - belongs_to: [Report, Post, Page, Staff, Event, SuccessStory, Resource, InvestmentPriority]
        via: featured_media
  - name: TaxonomyTerm
    surface: wordpress
    description: >-
      A term in one of ARC's 34 public vocabularies. The join table of the whole content model.
    fields: [id, count, description, link, name, slug, taxonomy, parent, meta]
    key_vocabularies:
      states_counties: 446 terms — the states and counties of the Appalachian Region
      tax_year: 70 terms
      staff_topic: 38 terms
      global_type: 31 terms
      investment_priority_topic: 22 terms
      research_report_eval_topic: 19 terms
  - name: FeatureService
    surface: arcgis
    count_observed: 108
    description: >-
      A hosted feature service in ARC's ArcGIS Online organization. Advertises capabilities Query
      only; hasStaticData true on the layers observed.
    fields: [name, type, url, serviceDescription, copyrightText, capabilities, maxRecordCount, supportedQueryFormats, layers]
    relationships:
      - has_many: FeatureLayer
        via: layers
  - name: FeatureLayer
    surface: arcgis
    description: A single layer inside a feature service. Every ARC service observed carries exactly one, at index 0.
    fields: [id, name, type, geometryType, objectIdField, fields, maxRecordCount, supportedQueryFormats, advancedQueryCapabilities]
    relationships:
      - has_many: Feature
        via: /query
  - name: Feature
    surface: arcgis
    description: >-
      One county, district or boundary polygon with its attributes. The arc_counties layer holds 423
      of them — the counties of the Appalachian Region — keyed on FIPS.
    fields_observed: [OBJECTID, FIPS, STATE, COUNTY, ARC, Shape__Area, Shape__Length]
    join_key: FIPS
    note: >-
      FIPS is the only cross-layer key. The economic-status, poverty, income, SNAP, education and
      population layers all repeat FIPS/STATE/COUNTY/ARC and add year-suffixed measure columns
      (for example CLF2024, UNRATE2024, PCI2024, PCMIUS2024 on the FY2027 economic-status layer),
      so joins across years and measures are FIPS joins.
graph_gaps:
  - >-
    No identifier connects a WordPress Map or Report record to the ArcGIS feature service that
    holds its data. An agent that wants the numbers behind a published ARC map must find the
    service by name in the services directory.
  - >-
    LocalDevelopmentDistrict exists in both graphs (74 posts, and the
    arc_local_development_districts feature service) with no shared key.
  - >-
    investment_priority (9 posts) and investment_priority_topic (22 terms) are separate vocabularies
    covering overlapping ground.
render: null
maintainers:
  - FN: Kin Lane
    email: info@apievangelist.com