aid: usda-snap
name: USDA SNAP Retailer Locator
review:
  question: Does the USDA SNAP API expose a documented public WebSocket API?
  answer: false
  date: '2026-07-03'
  reviewer: API Evangelist
  asyncapiSpecCreated: false
  asyncapiScopeNote: |
    No AsyncAPI document was authored. The USDA Food and Nutrition
    Administration's public SNAP Retailer Locator data is published as an
    Esri ArcGIS hosted Feature Service - a request/response REST interface
    over HTTPS (query, with JSON/GeoJSON/PBF encodings). There is no
    server-push transport (WebSocket or SSE) on this API to model, so no
    AsyncAPI document applies.
findings:
  summary: |
    USDA FNS/FNA does not publish a bespoke developer API at fns.usda.gov or
    api.fns.usda.gov for SNAP. Instead, the real, live, public "SNAP
    Retailer Locator API" is an anonymous, read-only Esri ArcGIS Feature
    Service - snap_retailer_location_data (ArcGIS item
    8b260f9a10b0459aa441ad8588c2251c) - hosted at
    services1.arcgis.com/RLQu0rK7h4kbsBq5/arcgis/rest/services/snap_retailer_location_data/FeatureServer.
    This exact service is embedded in FNA's own public tool at
    https://www.fna.usda.gov/snap/retailer-locator (confirmed via a direct
    link from that page to the matching ArcGIS Hub dataset explorer). As of
    June 1, 2026 the agency itself was renamed from the Food and Nutrition
    Service (FNS) to the Food and Nutrition Administration (FNA); both names
    still appear across USDA properties during the transition. The service
    was queried live on the review date: a nationwide count query
    (where=1=1, returnCountOnly=true) returned 254,048 currently authorized
    SNAP retailer records, and a filtered query (where=State='DC') returned
    real named retailers (convenience stores, a supermarket, etc.) with
    street addresses. The layer's only capability is "Query" - it is
    read-only, pure request/response REST/HTTP, with no realtime,
    bidirectional, or streaming WebSocket (ws:// or wss://) endpoint
    documented or observed anywhere in the service metadata.
  openSource: |
    Not applicable - this is a government open-data publication, not an
    open-source software project. The underlying dataset (currently
    authorized SNAP retailer locations) is public domain U.S. government
    data, freely queryable with no API key and exportable in bulk
    (CSV/Shapefile/GeoJSON/KML/Excel) from the ArcGIS Hub item page.
  transports:
    - protocol: REST
      scheme: https
      baseURL: https://services1.arcgis.com/RLQu0rK7h4kbsBq5/arcgis/rest/services/snap_retailer_location_data/FeatureServer
      documented: true
      note: Esri ArcGIS Feature Service query interface. Confirmed live and returning real nationwide retailer records on the review date.
    - protocol: WebSocket
      scheme: wss
      documented: false
      note: No WebSocket endpoint is documented anywhere in the ArcGIS Feature Service metadata or on the FNA retailer locator page.
sources:
  - url: https://www.fna.usda.gov/snap/retailer-locator
    type: Website
    note: Public retailer locator tool; links directly to the ArcGIS Hub explorer for dataset item 8b260f9a10b0459aa441ad8588c2251c, confirming this is the data source behind the tool. Also carries the FNS->FNA rename notice (effective 2026-06-01).
  - url: https://services1.arcgis.com/RLQu0rK7h4kbsBq5/arcgis/rest/services/snap_retailer_location_data/FeatureServer
    type: APIReference
    note: "Live service root, queried directly: capabilities='Query', maxRecordCount=1000, layers=[{id:0,name:snap_retailer_location_data}]."
  - url: https://services1.arcgis.com/RLQu0rK7h4kbsBq5/arcgis/rest/services/snap_retailer_location_data/FeatureServer/0
    type: APIReference
    note: "Live layer metadata, queried directly: geometryType=esriGeometryPoint, supportedQueryFormats=JSON,geoJSON,PBF, and the full field list (Record_ID, Store_Name, Store_Street_Address, Additonal_Address, City, State, Zip_Code, Zip4, County, Store_Type, Latitude, Longitude, Incentive_Program, Grantee_Name, ObjectId)."
  - url: https://services1.arcgis.com/RLQu0rK7h4kbsBq5/arcgis/rest/services/snap_retailer_location_data/FeatureServer/0/query
    type: APIReference
    note: "Live query endpoint, queried directly: where=1=1&returnCountOnly=true returned count=254048; where=State='DC' returned real retailer records (e.g. '24 Hours Tobacco & Grocery 1', 3728 Minnesota Ave NE, Washington DC 20019, Convenience Store)."
  - url: https://www.arcgis.com/home/item.html?id=8b260f9a10b0459aa441ad8588c2251c
    type: Documentation
    note: ArcGIS Online item page for the dataset, owned by FNS_SNAP_RPMD, titled SNAP_Retailer_Location_data.
  - url: https://usda-snap-retailers-usda-fns.hub.arcgis.com/datasets/USDA-FNS::snap-retailer-location-data/
    type: Documentation
    note: ArcGIS Hub dataset landing page (USDA-FNS organization) offering CSV/KML/Zip/GeoJSON/GeoTIFF/PNG download alongside GeoServices/WMS/WFS API links.
  - url: https://catalog.data.gov/dataset/snap-retail-locator
    type: Documentation
    note: data.gov catalog listing for the SNAP Retail Locator, linking to the public-facing tool.
actions:
  asyncapiPath: null
  apisYmlUpdated: true
  reason: |
    No WebSocket protocol surface exists. The confirmed public API is a
    read-only, anonymous, request/response REST interface (Esri ArcGIS
    Feature Service) with no server-push transport to model in an AsyncAPI
    document.