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: Carnegie Mellon University
providerId: carnegie-mellon-university
created: '2026-06-03'
modified: '2026-08-19'
reconciled: true
generated: '2026-08-19'
method: probed
source: >-
  Live probes of https://api.delphi.cmu.edu/epidata, https://kb.cert.org/vuls/api and
  https://lps.library.cmu.edu/api on 2026-08-19, plus the prose documentation at
  https://cmu-delphi.github.io/delphi-epidata/.
x-operator: institution
tags:
- Education
- Higher Education
- University
- Rate Limiting
description: >-
  Carnegie Mellon University publishes no rate-limit table for any API it operates, and no rate-limit
  headers were observed on any of the three institution-operated surfaces probed on 2026-08-19. The
  three surfaces come from three unrelated units and share no throttling policy: the Delphi Epidata
  API asks in prose only that heavy users be considerate; the CERT/CC Vulnerability Notes API states
  nothing at all; the Library Publishing Service's Django REST Framework endpoints paginate at a
  default limit of 100 with limit/offset, which bounds page size but is not a rate limit. The OAI-PMH
  provider uses resumptionToken pagination and, like most OAI-PMH providers, will throttle
  inconsiderate harvesting even though nothing is published about when. Rewritten 2026-08-19; the
  previous version described "OAI-PMH, IIIF, library" endpoints, and CMU operates no IIIF surface.
notes: >-
  No published limits and no observed 429s or X-RateLimit headers. Harvest politely, honor
  Retry-After if it ever appears, and expect no advance notice of a limit being introduced —
  CMU publishes no changelog on any API host.
sources:
- https://raw.githubusercontent.com/api-evangelist/carnegie-mellon-university/refs/heads/main/apis.yml
responseCodes:
  throttled: 429
limits:
- name: Default
  scope: client
  metric: requests-per-minute
  limit: see service documentation
  notes: No published global limit; large harvests may be rate-limited.
policies:
- name: Backoff Strategy
  description: Exponential backoff with jitter; honor Retry-After; harvest during off-peak hours.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com