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: Universität Hamburg
providerId: universitat-hamburg
created: '2026-06-03'
modified: '2026-09-01'
reconciled: false
tags:
- Education
- Higher Education
- University
- Rate Limiting
description: >-
  Universität Hamburg does not publish a unified public rate-limit table across its APIs. Open
  metadata and harvesting endpoints (OAI-PMH, IIIF, library) may throttle large-scale
  or automated harvesting; clients should harvest politely, honor Retry-After, and
  contact the relevant service for bulk access.
notes: Confirm per-service limits with each API's documentation; harvest responsibly.
sources:
- https://raw.githubusercontent.com/api-evangelist/universitat-hamburg/refs/heads/main/apis.yml
- https://www.fdr.uni-hamburg.de/api/records/?size=1
responseCodes:
  throttled: 429
limits:
- name: ZFDM Research Data Repository API
  scope: client
  metric: requests-per-window
  limit: 5000
  headers:
  - X-RateLimit-Limit
  - X-RateLimit-Remaining
  - X-RateLimit-Reset
  generated: '2026-09-01'
  method: probed
  source: https://www.fdr.uni-hamburg.de/api/records/?size=1
  notes: >-
    Observed live 2026-09-01 on https://www.fdr.uni-hamburg.de/api — response
    headers advertise X-RateLimit-Limit 5000 with X-RateLimit-Remaining and a
    Unix-epoch X-RateLimit-Reset. The window length is not stated in the headers
    and is not documented by the institution. No 429 was induced during probing.
- name: Default
  scope: client
  metric: requests-per-minute
  limit: see service documentation
  method: derived
  notes: >-
    No published global limit across the OAI-PMH endpoints; 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