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: Department of the Treasury
providerId: department-of-the-treasury
created: '2026-05-04'
# Provenance stamped 2026-08-11: this artifact was written by the API Evangelist
# bulk sweep dated 2026-05-04, not harvested from the provider. See roadmap#35.
method: generated
modified: '2026-05-05'
reconciled: true
tags:
  - Federal Government
  - Finance
  - Sanctions
  - Open Data
  - Rate Limiting
description: Treasury APIs split into two regimes. Fiscal Data and SAM.gov Entity Management are fronted
  by api.data.gov, which enforces a default 1,000-requests-per-hour limit per developer key (raisable
  via support). OFAC's Sanctions List Service and TreasuryDirect open feeds are unauthenticated and bounded
  by fair-use rather than per-key quotas. api.data.gov surfaces 429 with X-RateLimit-* headers; OFAC and
  TreasuryDirect use standard server throttling.
sources:
  - https://api.data.gov/docs/
  - https://fiscaldata.treasury.gov/api-documentation/
  - https://sanctionslistservice.ofac.treas.gov/
headers:
  limit: X-RateLimit-Limit
  remaining: X-RateLimit-Remaining
  reset: X-RateLimit-Reset
  retryAfter: Retry-After
responseCodes:
  throttled: 429
  quotaExceeded: 429
  serviceUnavailable: 503
  forbidden: 403
limits:
  - tier: api-data-gov
    name: api.data.gov default per-key limit
    scope: api-key
    metric: requests_per_hour
    limit: 1000
    timeFrame: hour
    applies:
      - Treasury Fiscal Data API
      - SAM.gov Entity Management API
  - tier: api-data-gov
    name: api.data.gov increased limit (raise via support)
    scope: api-key
    metric: requests_per_hour
    limit: 'higher; request via api.data.gov support'
    applies:
      - Treasury Fiscal Data API
      - SAM.gov Entity Management API
  - tier: open
    name: OFAC SLS / TreasuryDirect / IRS Fair-Use Throttle
    scope: IP
    metric: requests_per_minute
    limit: 'fair-use; not published'
    applies:
      - OFAC Sanctions List Service API
      - TreasuryDirect Securities API
      - IRS Public APIs
policies:
  - name: api.data.gov Key Pattern
    description: Fiscal Data and SAM.gov enforce limits at the api.data.gov gateway; excess returns 429.
      Increases must be requested via api.data.gov support.
  - name: OFAC SLS Bulk Pattern
    description: OFAC publishes daily refreshed lists; consumers should download once per day rather than
      poll. Fair-use limits apply at the network edge.
  - name: Backoff Strategy
    description: On 429 / 503 implement exponential backoff with jitter, honoring Retry-After when present.
  - name: Caching Encouragement
    description: Fiscal Data datasets are stable on a daily-or-weekly cadence; cache results aggressively
      to reduce gateway load.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com