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: Tsinghua University
providerId: tsinghua
created: '2026-06-03'
modified: '2026-08-19'
reconciled: false
tags:
- Education
- Higher Education
- University
- Rate Limiting
description: 'Tsinghua University publishes no rate-limit documentation of any kind, and none of its three
  publicly reachable machine-readable endpoints returned a rate-limit header, a Retry-After, or a 429
  in a full probe pass on 2026-08-19. The one throttle-shaped behaviour observed is not a rate limit at
  all: the TUNA mirror edge answers HTTP 403 with an HTML denial page to requests carrying a desktop-browser
  User-Agent, while answering the identical request 200 for a plain tool User-Agent. Callers should still
  harvest politely — the mirror is a shared community resource and the ISO catalog response alone is 461KB.'
notes: Corrected 2026-08-19. The June 2026 version of this file described throttling on "OAI-PMH, IIIF,
  library" harvesting endpoints; no such endpoints exist on any Tsinghua host. No 429 was observed and
  no rate-limit header is published.
sources:
- https://raw.githubusercontent.com/api-evangelist/tsinghua/refs/heads/main/apis.yml
- https://raw.githubusercontent.com/api-evangelist/tsinghua/refs/heads/main/errors/tsinghua-errors.yml
responseCodes:
  throttled: 429
  observed: none — no 429 returned in any probe; 403 observed but it is a User-Agent filter, not a rate
    limit
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
generated: '2026-08-19'
method: probed