OpenAPI Specification

The OpenAPI Specification (formally known as Swagger specification) is a standard to describe REST APIs in a human and computer readable format and allow several features like interactive documentation and automated client generation.

GET /__api__

Returns the OpenAPI description for the running instance of Kinto on JSON format.


Getting the description from this endpoint is the only way to get the full description for the running instance. The description returned is based on the Service definitions and the configuration file.

Known limitations

OpenAPI 2.0 currently doesn’t support some features that are present on Kinto API. Some known limitations are:

  1. Lack of validation on OR clauses (e.g. provide data or permissions in PATCH operations), which are trated as non-required on the description. This is more critical when setting Batch operations, which all the fields should be either defined on each request on the requests array or on the default object.
  2. No support for query filters on properties. Only named parameters are accepted on OpenAPI 2.0, so these are not included on the specification.
  3. Optional response headers are not supported, as required for Backoff signs.
  4. Collection defined schemas fields are not validated because they accept any JSON Schema definition, which may be too complex to be handled by an OpenAPI description. Only the type of the field is checked as a valid JSON object.
  5. Multiple schemas tagging different Content-Types for a same endpoint are not supported, so we don’t document JSON Patch operations.


The specifications used for loose schemas (objects that accept extra attributes of any type) include an additionalAttributes: {} definition that is not documented on the OpenAPI 2.0 Specification, but that allow loose schemas to be compatible with with several services created for OpenAPI/Swagger documented APIs, including code generators and interactive documentation renderers.

Interactive documentation

One way to interact and explore an API is through interactive documentation. SwaggerUI is a resource that allows testing and visualizing the behavior of an OpenAPI described interface.

You can try the instance running on from you browser accessing this Swagger UI example

Automated client generation

We support clients from a few languages like JavaScript, Python and Java, but if you need a client in a language that is currently not supported or want to have your own personalized interface, you can speedup your development by using Swagger Code Generator, which generates standardized clients for APIs in more than 25 languages.

Improving the documentation

The Kinto OpenAPI description relies on Cornice Swagger, which is an extension for Cornice that extracts API information from service definitions. Cornice Swagger also needs some information that is not on the service such as Tags, Possible Responses and operation IDs, so you may upgrade those on the Kinto service definitions. Also you can contribute to Cornice Swagger directly.

Documenting your plugin

The current implementation supports extensions as follows:

  • If the plugin defines views using Kinto or Cornice services, you can document it as a standard service as explained on the Cornice Swagger documentation.
  • If the plugin changes the possible responses for a Resource, you can document it by subclassing kinto.core.resource.schema.ResourceReponses and changing the responses attribute on your Resource ViewSet.
  • If the plugin adds an authentication method, you may declare it using kinto.core.openapi.OpenAPI.expose_authentication_method().