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 Southampton
providerId: university-of-southampton
created: '2026-06-03'
modified: '2026-08-30'
generated: '2026-08-30'
method: probed
reconciled: true
source: >-
  Rewritten on 2026-08-30 from live probes of every institution-operated surface. The previous
  version of this file, written 2026-06-03 with no recorded authorship, described throttling on
  "OAI-PMH, IIIF, library" endpoints; the University operates no IIIF service and no public library
  API, so those were template claims rather than measurements and have been removed.
tags:
- Education
- Higher Education
- University
- Rate Limiting
description: >-
  The University of Southampton publishes no rate-limit policy, no quota and no plan, and no
  institution-operated surface returned a RateLimit, X-RateLimit or Retry-After header in any probe
  on 2026-08-30. Access is unmetered and anonymous. The practical constraints on a client are not
  rate limits at all but two other mechanisms: a proof-of-work bot challenge in front of the
  repository host, and unpaginated bulk responses that are large enough to constitute a
  self-limiting resource.
notes: >-
  No 429 was observed on any surface. The documented throttled response code below is a
  convention, not an observation — do not read it as a published policy.
responseCodes:
  throttled: 429
  observed_throttling: none
limits:
- name: Open Data Service
  scope: client
  metric: none published
  limit: unmetered
  observed_headers: none
  notes: >-
    No rate-limit headers on any response. The real constraint is response size: dataset dumps are
    unpaginated and vary from 46,377 bytes (data-catalog) to 21,137,305 bytes (bus-info, still
    streaming at a 25-second timeout). Stream rather than buffer.
- name: ePrints Soton OAI-PMH
  scope: client
  metric: none published
  limit: unmetered
  observed_headers: none
  notes: >-
    No rate-limit headers. Paging is via the OAI-PMH resumptionToken, which is the protocol's own
    flow-control mechanism and should be used for any bulk harvest.
- name: ePrints Soton REST
  scope: client
  metric: none published
  limit: unmetered
  observed_headers: none
  notes: >-
    No rate-limit headers. The unfiltered listing at /rest/eprint/ had streamed 11,485,184 bytes
    without completing at a 25-second timeout; retrieve records individually by identifier.
- name: Shibboleth SAML Identity Provider
  scope: registered service provider
  metric: not applicable
  limit: not applicable
  notes: >-
    Access is governed by federation registration, not by rate. An unregistered client cannot make
    a meaningful request at all.
policies:
- name: Bot challenge, not a rate limit
  description: >-
    eprints.soton.ac.uk runs Anubis 1.24.0 in front of both its OAI-PMH and REST surfaces. It keys
    off User-Agent rather than request rate: browser-like strings receive HTTP 401 with a
    proof-of-work challenge, known crawler agents such as Googlebot receive HTTP 403, and plain or
    harvester User-Agents are served normally with HTTP 200. Backing off will not clear a 401 here;
    changing the User-Agent will.
- name: Licence boundary on bulk retrieval
  description: >-
    The repository's own dataPolicy permits transient robot harvesting of full items but requires
    permission for permanent harvesting and prohibits commercial resale. That is a licence
    constraint, not a technical one, and it is not enforced by the endpoint.
- name: Backoff Strategy
  description: >-
    Exponential backoff with jitter and honouring Retry-After remains the correct default, but note
    that no Retry-After header was observed on any surface during probing.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com