# Specifications

The `specifications` topic includes specifications proper, mechanisms for extending these specifications as required, and tools supporting the development and creation of new specifications.

## OpenActive specifications

* [**modelling-opportunity-data**](https://github.com/openactive/modelling-opportunity-data)**:** Backend repo for the [Opportunity specification](https://www.openactive.io/modelling-opportunity-data/), modelling sport and fitness-related events.
* [**open-booking-api**](https://github.com/openactive/open-booking-api)**:** Backend repo for the [Open Booking API,](https://www.openactive.io/open-booking-api/EditorsDraft/)  modelling [Opportunity](https://www.openactive.io/modelling-opportunity-data/) booking.
* [**realtime-paged-data-exchange**](https://github.com/openactive/realtime-paged-data-exchange)**:** Backend repo for the [Realtime Paged Data Exchange](https://www.w3.org/2017/08/realtime-paged-data-exchange/) specification, specifying chunking and sequencing for data feeds consisting of [Opportunity](https://www.openactive.io/modelling-opportunity-data/) (and in some cases [Booking](https://www.openactive.io/open-booking-api/EditorsDraft/)) data.
* [**routes**](https://github.com/openactive/routes)**:** Backend repo for the Routes specification, modelling Opportunities that involve walking, hiking, cycling, and other routes. Work-in-progress.
* [**dataset-api-discovery**](https://github.com/openactive/dataset-api-discovery)**:** Backend repo for the Dataset API Discovery specification, outlining the conformance criteria for dataset sites to make them parseable and discoverable by automated agents. A work in progress.

## Extension mechanisms

* [**ns-beta**](https://github.com/openactive/ns-beta)**:** Namespace for use by data publishers introducing properties not currently supported in OpenActive specifications, but which are under review by the community and stand as plausible candidates for inclusion in future drafts.
* [**extensions**](https://github.com/openactive/extensions)**:** Repository for the Opportunity Model Extensions vocabulary. Currently empty.
* [**extension-documentation-generator**](https://github.com/openactive/extension-documentation-generator)**:** Given a JSON-LD extension context, generates a README.md file.

## **Tools to support specification creation**

* [**ns**](https://github.com/openactive/ns)**:** Linked Data definitions and source for the OpenActive namespace
* [**spec-template**](https://github.com/openactive/spec-template)**:** Template for the creation of OpenActive specifications.