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: National University of Singapore
providerId: nus
created: '2026-06-03'
modified: '2026-08-19'
reconciled: false
tags:
- Education
- Higher Education
- University
- Rate Limiting
description: National University of Singapore publishes no rate-limit documentation for any surface, and
  no NUS response observed on 2026-08-19 carried RateLimit, X-RateLimit or Retry-After headers. The institution-operated
  identity service at vafs.nus.edu.sg advertises no throttling policy. The ScholarBank@NUS OAI-PMH and
  DSpace REST interfaces are tenant surfaces whose limits are set by Atmire Open Repository, not by NUS;
  harvest politely and honour Retry-After if it ever appears. The NUSMods API, which is a student organisation's
  and not the university's, is the only related surface that states a policy at all - its specification
  says it is not rate limited and asks consumers to fetch no more than once per day.
notes: No published limits anywhere in the NUS estate. Prior version of this file asserted throttling
  on "IIIF, library" endpoints that were never confirmed to exist; that claim has been removed.
sources:
- https://vafs.nus.edu.sg/adfs/.well-known/openid-configuration
- https://scholarbank.nus.edu.sg/oai/request?verb=Identify
- https://api.nusmods.com/v2/swagger.yaml
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
generated: '2026-08-19'
method: probed