OAS 3.0.0 Released!

OAS 3.0.0 Change Log

The OAI is pleased to announce the official release of the OpenAPI Specification 3.0.0!

The list below reflect the changes since the last release candidate.

Schema Changes

• The headers map under the Encoding Object can now also reference headers.

Descriptive Changes

• Reworded descriptions for clearer intent (no change of meaning).
• The OpenAPI Definition File has been renamed as the OpenAPI Document.
• Changes to better conform to RFC 2119.
• Elaborated Request Body's and Response's content field support media type ranges.
• Fixed descriptions of operationRef and operationId under the Link Object. Also clarified that a Link MUST contain one of them.
• Added links to OAuth2's and OpenID Connect's specifications.

Document Changes

• Some example fixes.

Check it out! https://github.com/OAI/OpenAPI-Specification/blob/3.0.0/versions/3.0.0.md

OAS 3.0.0-rc2 Released!

OAS 3.0.0-rc2 Change Log

Schema Changes

• The following objects have been removed from the specification: Server Variables, Content, Encoding, Callbacks, Headers, Links, Link Parameters, Scopes. They have all been replaced by the Map construct being effectively what they are. Clarifies that specification extensions are not allowed, as they did not make sense.
• The Encoding Property Object has been renamed to the Encoding Object. This is a result of the above change.
• The Encoding Object now specifies to which media type each property is applicable.
• The Encoding Object now defines headers as a map of Header Objects.
• The different components under the Components Object can now either be defined inline or referenced.
• For parameters using content, now only one media type can be used at most.
• The headers property under the Link Object has been removed.
• Link Object has a new requestBody property to allow passing a request body.
• The Schema Object's discriminator property has been completely reworked to utilize the newly supported oneOf and anyOf. A new Discriminator Object has been added to support these changes.
• The XML Object's namespace now MUST be an absolute URI.
• The apiKey security scheme can now also be in cookie.

Descriptive Changes

• The Rich Text Formatting section has been reworded to ease the requirements.
• Added OpenAPI Definition File definition.
• Clarified that an empty or nonexisting servers would default to a single Server with the url value of /.
• Reworded the section explaining the specification's versioning scheme.
• Server Variable enum's description has been fixed to state it can only be a string (the type was correct).
• Added clarification + examples how path matching works for paths defined under the Paths Object.
• Removed recommendation for a 120 character limit for the summary field under the Operation Object.
• Further details added to the form and simple types of style.
• Clarified that the Encoding Object applies to both multipart and application/x-www-form-urlencoded and only those.
• Clarified the possible response code wildcards are only 1XX, 2XX, 3XX, 4XX or 5XX.
• Variable Expressions have been renamed to Runtime Expressions. They have been unified between Links and Callbacks, and have a dedicated section. Various examples have been moved and removed as a result.
• Runtime expressions now use curly braces when found inside strings.
• Link Object's parameters now defines how to deal with cases of parameter name ambiguity.

Document Changes

• ToC has been updated to reflect changes.
• Fixed various anchors in the document.
• Various examples have been fixed.
• Various editorial changes were made to make the document more readable.

Check it out! https://github.com/OAI/OpenAPI-Specification/blob/3.0.0-rc2/versions/3.0.md

OAS 3.0.0-rc1 Released!

OAS 3.0.0-rc1 Change Log

Schema Changes

• url is now required under the Server Object.
• Server Variable Object's enum and default values are now string only (were any primitive).
• servers under the Path Item Object and Operation Object has been fixed to be an array of Server Objects and not a single one.
• The example and examples fields have been reworked, alongside the Example Object. There is no longer examples field under the Schema Object. Where examples exist, they are now a map of named examples with additional metadata for each example. The Example Object now has defined fields and is not free-form.
• content is now required under the Request Body Object.
• href under the Link Object has been renamed to operationRef, its description is clarified as well.
• The deprecated field under the Schema Object now defaults to false.
• The flow field under the Security Scheme Object has been renamed to flows.
• Request Body's required now defaults to false.
• Added allowReserved to the Encoding Property Object.

Descriptive Changes

• termsOfService now MUST be in the form of a URL.
• all description fields now support CommonMark.
• Clarified that specific response codes (200 for example) take precedence over response ranges (2XX for example).
• Clarified that for Parameter Object, either schema or content are required.
• pattern under the Schema Object now specifies the regex flavor.
• Added header restrictions. "Accept", "Content-Type", "Authorization" header paramters and "Content-Type" response headers will now be ignored.
• Referenced a specific version of supported CommonMark.
• Added clarifications to null not being a type (as opposed to a value).

Document Changes

• ToC has been updated to reflect changes.
• Fixed various anchors in the document.
• Various examples have been fixed.

Check it out! https://github.com/OAI/OpenAPI-Specification/blob/3.0.0-rc1/versions/3.0.md

OAS 3.0.0-rc0 Released!

We're happy to announce the release of the first Implementer's Draft of OAS 3.0.0, known as 3.0.0-rc0.

A lot of changes in this release, as a first one goes, so expect the change log to be updated. An initial list of changes, in no particular order:

• Changed the versioning scheme of the spec.
• Reusable definitions in the spec has been expanded and reorganized under the Components Object.
• Added support for operation callbacks.
• Added support for a new static linking between responses and operations.
• Reworked parameters - removed formData parameters, added cookie parameters, changed body parameters to Request Body Objects as a separate entity.
• Parameters now support complex types.
• Responses support multiple media type specifications.
• Reworked file support. Dropped file as a type, but provided better handling for file uploads and downloads.
• Reworked security definitions to allow for support for more schemes.
• Improved support for examples throughout the spec.
• Added support for defining multiple servers hosting the API, including URL variables.

Check it out! https://github.com/OAI/OpenAPI-Specification/blob/3.0.0-rc0/versions/3.0.md

Our blog post contains more details of the process and next steps.