specification: API Commons Rate Limits
specificationVersion: '0.1'
schema: https://raw.githubusercontent.com/api-evangelist/interface-research/main/schema/api-commons.yml#/$defs/RateLimits
provider: Federal Highway Administration
providerId: federal-highway-administration
generated: '2026-09-09'
method: searched
source: >-
  openapi/federal-highway-administration-v2x-app-api-openapi.json,
  https://github.com/usdot-fhwa-stol/v2x-app-api/blob/develop/README.md
created: '2026-05-04'
modified: '2026-09-09'
tags:
  - Federal Government
  - Transportation
  - Rate Limiting
description: >-
  FHWA publishes no rate limits. The V2X App API contract declares no 429 response on any of
  its 40 operations and no RateLimit-*, X-RateLimit-* or Retry-After header anywhere. This
  file replaces a 2026-05-04 bulk-sweep scaffold that invented free/professional/enterprise
  request ceilings and a full set of response headers; none of them appear in any FHWA
  contract or document.
limit_count: 0
limits: []
headers: {}
responseCodes: {}
observed:
  status_429_declared: false
  rate_limit_headers_declared: false
  retry_after_declared: false
  probed_operations: 40
adjacent_quotas:
  note: >-
    The API does model quotas, but they are REGISTRATION limits, not request rates: the
    /prd/v2/admin/vendor-limits and /prd/v2/admin/user-limits surfaces cap how many ETX
    MQTT registrations a vendor or a user may hold. The ceiling values are set by whoever
    operates the deployment; FHWA publishes no defaults.
  operations:
    - getAllVendorLimits
    - createOrUpdateVendorLimits
    - getAllUserLimits
    - createOrUpdateUserLimits
  schemas:
    - VendorLimitsRequest
    - VendorLimitsResponse
    - UserLimitsRequest
    - UserLimitsResponse
gap:
  finding: >-
    An agent calling this API has no runtime backpressure signal. Nothing tells it when to
    slow down and nothing tells it when to retry.
  remedy_for_provider: >-
    Declare a 429 response and emit RFC 9331-style RateLimit-Limit / RateLimit-Remaining /
    RateLimit-Reset plus Retry-After, and document them in the OpenAPI contract.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com