# Caltech Shibboleth Identity Provider (InCommon)

**Canonical:** https://apis.io/apis/caltech/identity-federation/  
**Provider:** California Institute of Technology — https://apis.io/providers/caltech/  
**Base URL:** https://idp.caltech.edu/idp/shibboleth  
**Documentation:** https://www.imss.caltech.edu/

Caltech Shibboleth Identity Provider (InCommon) is one of 11 APIs that [California Institute of Technology](https://apis.io/providers/caltech/) publishes on the [APIs.io](https://apis.io/) network. Tagged areas include Identity Federation, Shibboleth, SAML, InCommon, and eduGAIN. The published artifact set on APIs.io includes sample payloads.

Caltech operates its own Shibboleth identity provider at idp.caltech.edu, asserting scoped attributes for caltech.edu. The SAML 2.0 metadata is machine-readable and publicly retrievable both from the IdP itself and, signed, from the InCommon metadata query service — registrationAuthority https://incommon.org, and therefore reachable through eduGAIN. Advertises SAML 1.1, SAML 2.0 and the Shibboleth-native AuthnRequest binding, with HTTP-POST, HTTP-Redirect and POST-SimpleSign SSO bindings and a SOAP attribute authority. Verified live 2026-08-19 from both sources. This is the single most under-catalogued class of university API surface.

## Machine-readable artifacts (4)

- **Metadata** — https://idp.caltech.edu/idp/shibboleth
- **Metadata** — https://mdq.incommon.org/entities/https%3A%2F%2Fidp.caltech.edu%2Fidp%2Fshibboleth
- **Example** — https://raw.githubusercontent.com/api-evangelist/caltech/refs/heads/main/examples/caltech-shibboleth-metadata-example.yml
- **Conformance** — https://raw.githubusercontent.com/api-evangelist/caltech/refs/heads/main/conformance/caltech-education-standards.yml

## Other California Institute of Technology APIs (10)

- [CaltechDATA REST API](https://apis.io/apis/caltech/caltechdata-rest/)
- [CaltechDATA OAI-PMH](https://apis.io/apis/caltech/caltechdata-oai/)
- [CaltechAUTHORS REST API and OAI-PMH](https://apis.io/apis/caltech/caltechauthors/)
- [Caltech Library Feeds](https://apis.io/apis/caltech/library-feeds/)
- [SCEDC FDSN Web Services](https://apis.io/apis/caltech/scedc-fdsn/)
- [IRSA Virtual Observatory APIs (Caltech/IPAC)](https://apis.io/apis/caltech/irsa-vo/)
- [NED Table Access Protocol (Caltech/IPAC)](https://apis.io/apis/caltech/ned-tap/)
- [NASA Exoplanet Archive TAP (Caltech/IPAC)](https://apis.io/apis/caltech/exoplanet-archive-tap/)
- [Caltech Library Guides (Springshare tenancy)](https://apis.io/apis/caltech/libguides-springshare/)
- [EBSCO Link Resolver (Caltech instance)](https://apis.io/apis/caltech/ebsco-resolver/)

## Tags

Identity Federation, Shibboleth, SAML, InCommon, eduGAIN, Single Sign-On

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/caltech/identity-federation/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/caltech/.