[2] [DFN[[[JSON API]]]] は、 [[JSON]] を用いた [[Web API]] のデータ形式の1つです。
[[MIME型]]は [DFN[[CODE(MIME)@en[[[application/vnd.api+json]]]]]] とされています。

;; [3] 大変紛らわしいことに、一般的に「[[JSON API]]」といえば [[JSON]] をデータ形式として使う任意の
[[API]] のことを指していますが、ここでいう「JSON API」は[[固有名詞]]です。
一般的な「[[JSON API]]」のほとんどは、ここでいう「JSON API」ではありません。
(悪意すら感じるネーミングですね。)

[REFS[
- [1] [CITE[JSON API :: A standard for building APIs in JSON.]]
( ([TIME[2014-06-09 16:18:31 +09:00]] 版))
<http://jsonapi.org/>
]REFS]

[4] [CITE[JSON API — Latest Specification (v1.0)]]
([TIME[2015-11-16 23:46:06 +09:00]] 版)
<http://jsonapi.org/format/>

[FIG(quote)[
[FIGCAPTION[
[5] [CITE[JSON API — JSON Patch Extension]]
([TIME[2016-03-20 23:22:07 +09:00]] 版)
<http://jsonapi.org/extensions/jsonpatch/>
]FIGCAPTION]

> Content-Type: application/vnd.api+json; ext=jsonpatch
> Accept: application/vnd.api+json; ext=jsonpatch

]FIG]


[FIG(quote)[
[FIGCAPTION[
[6] ([TIME[2013-07-22 15:39:05 +09:00]] 版)
<https://www.iana.org/assignments/media-types/application/vnd.api+json>
]FIGCAPTION]

> 
> Required parameters : none
> Optional parameters :
> none
> 

]FIG]


[FIG(quote)[
[FIGCAPTION[
[7] [CITE[JSON API — JSON Patch Extension]]
([TIME[2016-03-20 23:22:07 +09:00]] 版)
<http://jsonapi.org/extensions/jsonpatch/>
]FIGCAPTION]

> The server MUST specify a Content-Type header of application/vnd.api+json; ext=jsonpatch.

]FIG]


[FIG(quote)[
[FIGCAPTION[
[8] [CITE[JSON API — Latest Specification (v1.0)]]
([TIME[2016-03-20 23:22:07 +09:00]] 版)
<http://jsonapi.org/format/#content-negotiation-clients>
]FIGCAPTION]

> Client Responsibilities
> Clients MUST send all JSON API data in request documents with the header Content-Type: application/vnd.api+json without any media type parameters.
> Clients that include the JSON API media type in their Accept header MUST specify the media type there at least once without any media type parameters.
> Clients MUST ignore any parameters for the application/vnd.api+json media type received in the Content-Type header of response documents.
> Server Responsibilities
> Servers MUST send all JSON API data in response documents with the header Content-Type: application/vnd.api+json without any media type parameters.
> Servers MUST respond with a 415 Unsupported Media Type status code if a request specifies the header Content-Type: application/vnd.api+json with any media type parameters.
> Servers MUST respond with a 406 Not Acceptable status code if a request's Accept header contains the JSON API media type and all instances of that media type are modified with media type parameters.
> Note: The content negotiation requirements exist to allow future versions of this specification to use media type parameters for extension negotiation and versioning.

]FIG]

[9] 
その後 [DFN[JSON:API]] って書くようになったみたいですね。 (わかりにくいことはかわってないが。)