generated: '2026-09-06'
method: derived
status: candidate
source: >-
  No MCP server exists. Searched the ERS developer pages
  (https://www.ers.usda.gov/developer/), both ERS GitHub organizations (USDA-ERS,
  USDA-REE-ERS), the npm registry and the open web on 2026-09-06 and found nothing first-party.
  The tool list below is DERIVED from the resources ERS documents at
  https://www.ers.usda.gov/developer/data-apis/arms-data-api and the ArcGIS service catalog at
  https://gisportal.ers.usda.gov/server/rest/services?f=json - it is a proposal of what a
  server would expose, not a description of one that exists.
provider: Economic Research Service
providerId: economic-research-service
description: >-
  Candidate MCP tool surface for the ERS APIs. NOBODY SHIPS A SERVER - not ERS, not USDA, not a
  third party. Recorded as a candidate because the ARMS API is unusually well suited to one:
  seven resources, a small controlled vocabulary that is itself retrievable at runtime, no
  writes, no user data, and a single free key. The npm packages that surface in a "USDA MCP"
  search wrap FoodData Central, a different USDA agency's API, and none of them touch ERS.
deployment:
  mode: none
  endpoint: null
  install: null
  package: null
  auth: api-key
  auth_note: >-
    Any server built against ARMS would need to hold a free api.data.gov key; the geospatial
    services need no credential at all.
  verified: derived
tools:
  - name: arms_list_years
    rest: GET https://api.ers.usda.gov/data/arms/year
    description: List every year for which ARMS survey data are available.
    inputSchema: {}
    confidence: high
  - name: arms_list_states
    rest: GET https://api.ers.usda.gov/data/arms/state
    description: List all States with the metadata and variables available for each.
    inputSchema: {}
    confidence: high
  - name: arms_list_reports
    rest: GET|POST https://api.ers.usda.gov/data/arms/report
    description: >-
      List the eight tailored ARMS reports, or look one up by name, ID or keyword, with its
      metadata and available variables.
    inputs: [name, id, keyword]
    confidence: high
  - name: arms_list_variables
    rest: GET|POST https://api.ers.usda.gov/data/arms/variable
    description: List or search ARMS variables by ID, report, name or keyword.
    inputs: [id, report, name, keyword]
    confidence: high
  - name: arms_list_categories
    rest: GET|POST https://api.ers.usda.gov/data/arms/category
    description: >-
      List every breakdown category and its subcategories, or fetch one by name or by
      comma-separated short ID.
    inputs: [name, id]
    confidence: high
  - name: arms_list_farm_types
    rest: GET|POST https://api.ers.usda.gov/data/arms/farmtype
    description: List or search ARMS farm types by name, ID or keyword.
    inputs: [name, id, keyword]
    confidence: high
  - name: arms_get_survey_data
    rest: GET|POST https://api.ers.usda.gov/data/arms/surveydata
    description: >-
      Retrieve ARMS survey values. Requires year; requires at least one of report or variable.
      Optionally filtered by state and cross-tabulated by category, category_value, category2
      and farmtype.
    inputs: [year, state, report, variable, category, category_value, category2, farmtype]
    required: [year]
    one_of: [report, variable]
    confidence: high
  - name: ers_list_map_services
    rest: GET https://gisportal.ers.usda.gov/server/rest/services?f=json
    description: >-
      List the ERS ArcGIS map, feature and image services, by folder. No credential required.
    inputSchema: {}
    confidence: high
  - name: ers_describe_map_service
    rest: GET https://gisportal.ers.usda.gov/server/rest/services/{folder}/{service}/{type}?f=json
    description: >-
      Describe one ERS map or feature service - its layers, geometry types, spatial reference,
      supported query formats and record ceilings.
    inputs: [folder, service, type]
    confidence: high
  - name: ers_query_map_layer
    rest: GET https://gisportal.ers.usda.gov/server/rest/services/{folder}/{service}/MapServer/{layerId}/query
    description: >-
      Query features from one ERS map layer, returning JSON, GeoJSON or PBF. Honours the
      service's published maxRecordCount of 2000 and pages with resultOffset/resultRecordCount.
    inputs: [folder, service, layerId, where, outFields, geometry, f, resultOffset, resultRecordCount]
    confidence: medium
    note: >-
      Parameter set is Esri's documented ArcGIS REST query interface, not something ERS
      restates; confidence is medium because ERS defers to
      https://developers.arcgis.com/rest/ rather than publishing its own parameter reference.
schema_gap:
  note: >-
    inputSchema is deliberately left empty or reduced to a parameter name list. ERS publishes no
    OpenAPI and no GraphQL SDL, and the one runtime self-description it does offer - HTTP
    OPTIONS on each ARMS resource, which "returns the endpoint schema and details on input
    fields and requirements" - is behind the api.data.gov key gate (403 API_KEY_MISSING
    anonymously, probed 2026-09-06). A real server implementation should call OPTIONS on each
    resource with a key and generate the inputSchemas from that response rather than from this
    file.
graphql:
  endpoint: https://api.ers.usda.gov/data/arms/graphql
  documented: true
  schema_available: false
  note: >-
    An MCP server could plausibly be thinner over GraphQL than over the seven REST resources,
    but the SDL is not published and anonymous introspection is refused by the gateway.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com