sierra-ils-utils¶
The unofficial Sierra REST API field guide — for developers, builders, and hackers.
sierra-ils-utils is a small Python library that wraps HTTPX
to make the Sierra ILS REST API pleasant to work with: automatic OAuth2
token handling, sync and async requests, retries with backoff, and typed responses.
But this site is more than library docs. The Sierra REST API has sparse official documentation and a lot of non-obvious behavior. This guide collects what we learned the hard way — across real projects touching tens of thousands of records — so you don't have to discover it mid-batch on production data.
Where to go¶
- Get Started — new here? Go from zero to your first successful API call: get credentials, install, authenticate, and read a record.
- The Quirks Catalog — the crown jewel. Every gotcha we've hit:
additive
phones, full-replacevarFields, the 204 that isn't 200, timestamp side effects, ghost records — each with how to handle it and how we know.
A note on trust¶
The behaviors documented here were observed empirically on real Sierra deployments (production and test). Sierra deployments differ in version and configuration, so treat every quirk as "verify on your own deployment." Each catalog entry includes a How we know line so you can judge how solid the finding is — and the guide tells you how to probe safely yourself.
This is a community field guide, not an official Innovative/Clarivate product. Corrections and additions are welcome at GitHub.