Link Relationships
This document serves as the official registry of link relationships for the OPDS and ODL specifications.
Acquisition Links
| Value | Definition | Reference |
|---|---|---|
http://opds-spec.org/acquisition |
Fallback acquisition relation when no other relation is a good fit to express the nature of the transaction. | OPDS 1.2 |
http://opds-spec.org/acquisition/open-access |
Indicates that a publication is freely accessible without any requirement, including authentication. | OPDS 1.2 |
http://opds-spec.org/acquisition/borrow |
Indicates that a publication can be borrowed for a limited period of time. | OPDS 1.2 |
http://opds-spec.org/acquisition/buy |
Indicates that a publication can be purchased for a given price. | OPDS 1.2 |
http://opds-spec.org/acquisition/sample |
Indicates that a sub-set of the full publication is freely accessible at a given URI, without any prior requirement. This relationship is deprecated since the release of OPDS 2.0, preview should be used instead. |
OPDS 1.2 |
preview |
Indicates that a sub-set of the full publication is freely accessible at a given URI, without any prior requirement. | RFC6903 |
http://opds-spec.org/acquisition/subscribe |
Indicates that a publication be subscribed to, usually as part of a purchase and for a limited period of time. | OPDS 1.2 |
Collection or Feed-level Links
| Value | Definition | Use Case | Reference |
|---|---|---|---|
first |
An IRI that refers to the furthest preceding resource in a series of resources. | Provides a link to the first page when the current feed/collection is paginated. | RFC5988 |
last |
An IRI that refers to the furthest following resource in a series of resources. | Provides a link to the last page when the current feed/collection is paginated. | RFC5988 |
next |
Refers to the next resource in a ordered series of resources. | Provides a link to the next page when the current feed/collection is paginated. | HTML4 |
previous |
Refers to the previous resource in an ordered series of resources. Synonym for “prev”. | Provides a link to the previous page when the current feed/collection is paginated. | HTML4 |
start |
Refers to the first resource in a collection of resources. | Provides a link to the homepage of an OPDS Catalog. | HTML4 |
http://opds-spec.org/shelf |
A Resource that includes a user’s existing set of Acquired Content, which may be represented as an OPDS Catalog. | The shelf relationship is fairly widely used in the OPDS ecosystem to list all content acquired by a given user. | OPDS 1.2 |