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: University of Tübingen
providerId: university-of-tubingen
created: '2026-06-03'
modified: '2026-09-01'
generated: '2026-09-01'
method: probed
reconciled: true
tags:
- Education
- Higher Education
- University
- Rate Limiting
description: >-
  University of Tübingen publishes no rate-limit documentation page, but its FDAT research data
  repository advertises a concrete, machine-readable limit in response headers. A GET of
  https://fdat.uni-tuebingen.de/api/records/zvknn-g0x34 on 2026-09-01 returned
  X-RateLimit-Limit: 500, X-RateLimit-Remaining: 499, X-RateLimit-Reset: 1788292918 and
  Retry-After: 60 — a 500-request window with a 60-second reset, enforced per client by the
  InvenioRDM deployment. The OAI-PMH providers publish no headers; FDAT's robots.txt sets
  Crawl-delay: 10 and disallows /api and /search, which is the operator's stated harvesting
  posture even though the endpoints themselves are open.
notes: >-
  Header values were observed live, not inferred. No numeric limit is published for
  publikationen.uni-tuebingen.de (TOBIAS-lib OAI-PMH) or for the UB Tübingen discovery services,
  which instead sit behind a proof-of-work browser challenge that functions as the throttle.
sources:
- https://fdat.uni-tuebingen.de/api/records/zvknn-g0x34
- https://fdat.uni-tuebingen.de/robots.txt
- https://raw.githubusercontent.com/api-evangelist/university-of-tubingen/refs/heads/main/apis.yml
responseCodes:
  throttled: 429
headers:
- name: X-RateLimit-Limit
  observed: '500'
- name: X-RateLimit-Remaining
  observed: '499'
- name: X-RateLimit-Reset
  observed: '1788292918'
- name: Retry-After
  observed: '60'
limits:
- name: FDAT repository REST API
  scope: client
  metric: requests-per-minute
  limit: 500
  notes: >-
    Observed on live response headers 2026-09-01 (X-RateLimit-Limit 500, Retry-After 60). Applies
    to https://fdat.uni-tuebingen.de/api/*.
- name: OAI-PMH harvesting
  scope: client
  metric: requests-per-minute
  limit: 6
  notes: >-
    No numeric limit is advertised in headers. FDAT's robots.txt declares Crawl-delay: 10, i.e. six
    requests per minute is the operator's stated polite-harvest rate; treat it as guidance, not an
    enforced ceiling.
policies:
- name: Backoff Strategy
  description: Exponential backoff with jitter; honor Retry-After (60s on FDAT); harvest during off-peak hours.
- name: Crawl Delay
  description: FDAT robots.txt sets Crawl-delay 10 and disallows /api and /search for crawlers.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com