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 Housing Finance Agency (FHFA)
providerId: fhfa
created: '2026-06-13'
modified: '2026-06-13'
tags:
  - Housing Finance
  - House Price Index
  - Mortgage
  - Government
  - GSE
  - Federal
  - Rate Limiting
  - Quotas
description: >-
  FHFA does not publish formal rate limits for its public data API endpoints
  and dataset downloads. As a federal government agency, FHFA data is freely
  accessible to the public. Standard web server infrastructure limits apply,
  and the agency reserves the right to modify, limit, or terminate access
  at any time per the API Terms of Service. Consumers should implement
  reasonable request pacing and caching to avoid placing undue load on
  FHFA servers.
headers:
  limit: ''
  remaining: ''
  reset: ''
  retryAfter: Retry-After
  policy: ''
responseCodes:
  throttled: 429
  quotaExceeded: 429
  serviceUnavailable: 503
limits:
  - tier: public
    name: Public Access Default
    scope: ip-address
    metric: requests_per_minute
    limit: 60
    burst: 120
    timeFrame: minute
    applies:
      - FHFA House Price Index (HPI) API
      - FHFA National Mortgage Database (NMDB) API
      - FHFA Enterprise Public Use Database (PUDB) API
      - FHFA Conforming Loan Limits API
      - FHFA Uniform Appraisal Dataset (UAD) Aggregate Statistics API
    notes: >-
      No officially published rate limits exist. The value above is a
      conservative estimate for responsible usage. FHFA reserves the right
      to throttle or block access per its Terms of Service.
policies:
  - name: Attribution Required
    description: >-
      All applications and services using FHFA data must display the notice:
      "This product uses FHFA Data but is neither endorsed nor certified by FHFA."
  - name: Responsible Use
    description: >-
      Consumers should cache responses locally where feasible, since FHFA
      datasets are updated on monthly or quarterly schedules rather than
      in real time. Avoid repeatedly downloading large files unnecessarily.
  - name: Backoff Strategy
    description: >-
      Clients receiving 429 or 503 responses should implement exponential
      backoff with jitter and honor any Retry-After header returned.
  - name: Content Integrity
    description: >-
      Users must not falsely represent or modify FHFA data content while
      attributing it to FHFA as the source.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com