University of Tokyo · Rate Limits

University Of Tokyo Rate Limits

The University of Tokyo publishes no rate limit for any of its interfaces, and no 429 was observed on any probe. What it does enforce instead is edge access control, and it is unusual enough to be the operative constraint: repository.dl.itc.u-tokyo.ac.jp returns HTTP 406 to a desktop-browser User-Agent and 200 to a plain client (inverted from the usual bot challenge), while da.dl.itc.u-tokyo.ac.jp returns HTTP 403 on /portal/search to every external automated client regardless of User-Agent. Paging limits are protocol-level: the Archives Portal caps OAI-PMH ListRecords at 100 records per resumptionToken page, and its documented search API caps items_per_page at 200.

University Of Tokyo Rate Limits is the machine-readable rate-limit profile for University of Tokyo on the APIs.io network, conforming to the API Commons Rate Limits specification.

It captures 4 rate-limit definitions, measuring records-per-page, items-per-page, and requests-per-minute.

The profile also includes 2 backoff/retry policies defined and response codes documented for throttled and throttled_note.

Tagged areas include Education, Higher Education, University, and Rate Limiting.

4 Limits
EducationHigher EducationUniversityRate Limiting

Limits

OAI-PMH ListRecords page size protocol
records-per-page
100
Archives Portal cap, documented by the university. Continue with resumptionToken.
Archives Portal search page size protocol
items-per-page
200
Documented maximum and also the default when items_per_page is omitted. Endpoint returns 403 to external automated clients, so this is documented rather than observed.
Repository records default page size client
records-per-page
10
Observed default on /api/records/. Overridable with ?size=. No documented ceiling.
Global request rate client
requests-per-minute
none published
No published limit and no throttling observed.

Policies

Backoff Strategy
Exponential backoff with jitter and off-peak harvesting. No Retry-After is sent, so back off on any non-200 rather than waiting for a hint.
User-Agent Policy
Send a plain client User-Agent with a contact string to repository.dl.itc.u-tokyo.ac.jp; a browser-shaped User-Agent returns 406 there. Send a browser-shaped User-Agent to da.dl.itc.u-tokyo.ac.jp item paths. The two institution hosts require opposite settings.

Sources