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: USAspending.gov
providerId: usaspending
created: '2026-07-03'
modified: '2026-07-03'
reconciled: false
tags:
- Government
- Federal Spending
- Open Data
- Rate Limiting
- Quotas
description: >-
  The USAspending API does not require authentication (no API key, no
  registration) and does not publish fixed, numeric, per-endpoint or
  per-account rate limits in its official documentation. General search and
  reference endpoints are described by the USAspending.gov community as
  usable with generous, informal limits for individual researchers. The
  documented exception is the asynchronous Bulk Download API
  (/api/v2/bulk_download/), where the project's own support channel advises
  limiting concurrent bulk download requests and backing off after failures,
  because zip-file generation is resource intensive on the backend; no
  specific numeric threshold for the bulk endpoints is published, and there
  is no documented way for a client to check how close it is to any limit.
notes: >-
  Endpoints do not currently require any authorization, per the official
  endpoint documentation at api.usaspending.gov/docs/endpoints. Treat the
  lack of published numeric limits as "not published," not as "no limits" -
  the API may still return 429s or reset connections under heavy load,
  particularly on search endpoints with broad filters/date ranges and on
  bulk downloads. This entry should be reconciled if USAspending publishes
  explicit numeric limits in the future.
sources:
- https://api.usaspending.gov/docs/endpoints
- https://api.usaspending.gov/
- https://github.com/fedspendingtransparency/usaspending-api
- https://onevoicecrm.my.site.com/usaspending/s/question/0D5eq00001AwRpCCAV/api-rate-limitation
responseCodes:
  throttled: 429
limits:
- name: General API Requests
  scope: unauthenticated / anonymous
  metric: requests
  limit: not published
  notes: No API key or registration required; no fixed numeric rate limit documented for search, agency, recipient, federal account, or reference endpoints.
- name: Bulk Download Requests
  scope: unauthenticated / anonymous
  metric: concurrent download jobs
  limit: not published (community guidance suggests 1-2 concurrent)
  notes: Bulk zip-file generation is backend-intensive; USAspending's own support channel recommends limiting concurrent bulk downloads and waiting several minutes after a failed request before retrying.
- name: Search Result Window
  scope: request
  metric: rows per page
  limit: varies by endpoint (recipient list caps at 1000 per page)
  notes: Individual endpoints cap the "limit" request parameter (e.g. the Recipient list endpoint documents a maximum of 1000 rows per page); there is no single global cap across the API.
policies:
- name: No Authentication Required
  description: All documented endpoints are publicly accessible without an API key, OAuth token, or account registration.
- name: Bulk Download Backoff
  description: Community and support guidance recommends waiting roughly five minutes after a failed bulk download request and reducing concurrent bulk download requests to one or two before retrying.
- name: Retry-After Not Documented
  description: The API does not document a Retry-After header or other machine-readable backoff signal for 429 responses; clients should implement their own conservative exponential backoff.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com