The OpenAPI Specification (OAS) defines a standard, programming language-agnostic interface description for HTTP APIs, which allows both humans and computers to discover and understand the capabilities of a service without requiring access to source code, additional documentation, or inspection of network traffic. When properly defined via OpenAPI, a consumer can understand and interact with the remote service with a minimal amount of implementation logic. Similar to what interface descriptions have done for lower-level programming, the OpenAPI Specification removes guesswork in calling a service.
Status of This Document
The source-of-truth for this specification is the HTML file referenced above as This version.
+
What is the OpenAPI Specification?
The OpenAPI Specification (OAS) defines a standard, programming language-agnostic interface description for HTTP APIs, which allows both humans and computers to discover and understand the capabilities of a service without requiring access to source code, additional documentation, or inspection of network traffic. When properly defined via OpenAPI, a consumer can understand and interact with the remote service with a minimal amount of implementation logic. Similar to what interface descriptions have done for lower-level programming, the OpenAPI Specification removes guesswork in calling a service.
Status of This Document
The source-of-truth for this specification is the HTML file referenced above as This version.
1. OpenAPI Specification
-
1.1 Version 3.1.0
+
1.1 Version 3.1.1
The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “NOT RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.
The OpenAPI Specification (OAS) defines a standard, language-agnostic interface to HTTP APIs which allows both humans and computers to discover and understand the capabilities of the service without access to source code, documentation, or through network traffic inspection. When properly defined, a consumer can understand and interact with the remote service with a minimal amount of implementation logic.
-
An OpenAPI definition can then be used by documentation generation tools to display the API, code generation tools to generate servers and clients in various programming languages, testing tools, and many other use cases.
+
An OpenAPI Description can then be used by documentation generation tools to display the API, code generation tools to generate servers and clients in various programming languages, testing tools, and many other use cases.
+
For examples of OpenAPI usage and additional documentation, please visit [OpenAPI-Learn].
+
For extension registries and other specifications published by the OpenAPI Initiative, as well as the authoritative rendering of this specification, please visit spec.openapis.org.
3. Definitions
-
3.1 OpenAPI Document
-
A self-contained or composite resource which defines or describes an API or elements of an API. The OpenAPI document MUST contain at least one paths field, a components field or a webhooks field. An OpenAPI document uses and conforms to the OpenAPI Specification.
-
3.2 Path Templating
-
Path templating refers to the usage of template expressions, delimited by curly braces ({}), to mark a section of a URL path as replaceable using path parameters.
+
3.1 OpenAPI Description
+
An OpenAPI Description (OAD) formally describes the surface of an API and its semantics. It is composed of an entry document, which must be an OpenAPI Document, and any/all of its referenced documents. An OAD uses and conforms to the OpenAPI Specification, and MUST contain at least one paths field, components field, or webhooks field.
+
3.2 OpenAPI Document
+
An OpenAPI Document is a single JSON or YAML document that conforms to the OpenAPI Specification. An OpenAPI Document compatible with OAS 3.*.* contains a required openapi field which designates the version of the OAS that it uses.
+
3.3 Schema
+
A “schema” is a formal description of syntax and structure.
+This document serves as the schema for the OpenAPI Specification format; a non-authoritative JSON Schema based on this document is also provided on spec.openapis.org for informational purposes.
+This specification also uses schemas in the form of the Schema Object.
+
3.4 Object
+
When capitalized, the word “Object” refers to any of the Objects that are named by section headings in this document.
+
3.5 Path Templating
+
Path templating refers to the usage of template expressions, delimited by curly braces ({}), to mark a section of a URL path as replaceable using path parameters.
Each template expression in the path MUST correspond to a path parameter that is included in the Path Item itself and/or in each of the Path Item’s Operations. An exception is if the path item is empty, for example due to ACL constraints, matching path parameters are not required.
The value for these path parameters MUST NOT contain any unescaped “generic syntax” characters described by [RFC3986] Section 3: forward slashes (/), question marks (?), or hashes (#).
-
3.3 Media Types
+
3.6 Media Types
Media type definitions are spread across several resources.
The media type definitions SHOULD be in compliance with [RFC6838].
Some examples of possible media type definitions:
@@ -253,92 +288,270 @@
OpenAPI Specification v3.1.0
3.4 HTTP Status Codes
+
3.7 HTTP Status Codes
The HTTP Status Codes are used to indicate the status of the executed operation.
-The available status codes are defined by [RFC7231] Section 6 and registered status codes are listed in the IANA Status Code Registry.
+Status codes SHOULD be selected from the available status codes registered in the IANA Status Code Registry.
+
3.8 Case Sensitivity
+
As most field names and values in the OpenAPI Specification are case-sensitive, this document endeavors to call out any case-insensitive names and values.
+However, the case sensitivity of field names and values that map directly to HTTP concepts follow the case sensitivity rules of HTTP, even if this document does not make a note of every concept.
+
3.9 Undefined and Implementation-Defined Behavior
+
This specification deems certain situations to have either undefined or implementation-defined behavior.
+
Behavior described as undefined is likely, at least in some circumstances, to result in outcomes that contradict the specification.
+This description is used when detecting the contradiction is impossible or impractical.
+Implementations MAY support undefined scenarios for historical reasons, including ambiguous text in prior versions of the specification.
+This support might produce correct outcomes in many cases, but relying on it is NOT RECOMMENDED as there is no guarantee that it will work across all tools or with future specification versions, even if those versions are otherwise strictly compatible with this one.
+
Behavior described as implementation-defined allows implementations to choose which of several different-but-compliant approaches to a requirement to implement.
+This documents ambiguous requirements that API description authors are RECOMMENDED to avoid in order to maximize interoperability.
+Unlike undefined behavior, it is safe to rely on implementation-defined behavior if and only if it can be guaranteed that all relevant tools support the same behavior.
4. Specification
4.1 Versions
The OpenAPI Specification is versioned using a major.minor.patch versioning scheme. The major.minor portion of the version string (for example 3.1) SHALL designate the OAS feature set. .patch versions address errors in, or provide clarifications to, this document, not the feature set. Tooling which supports OAS 3.1 SHOULD be compatible with all OAS 3.1.* versions. The patch version SHOULD NOT be considered by tooling, making no distinction between 3.1.0 and 3.1.1 for example.
Occasionally, non-backwards compatible changes may be made in minor versions of the OAS where impact is believed to be low relative to the benefit provided.
-
An OpenAPI document compatible with OAS 3.*.* contains a required openapi field which designates the version of the OAS that it uses.
4.2 Format
-
An OpenAPI document that conforms to the OpenAPI Specification is itself a JSON object, which may be represented either in JSON or YAML format.
+
An OpenAPI Document that conforms to the OpenAPI Specification is itself a JSON object, which may be represented either in JSON or YAML format.
For example, if a field has an array value, the JSON array representation will be used:
{
- "field":[1,2,3]
+ "field":[1,2,3]}
All field names in the specification are case sensitive.
This includes all fields that are used as keys in a map, except where explicitly noted that keys are case insensitive.
-
The schema exposes two types of fields: Fixed fields, which have a declared name, and Patterned fields, which declare a regex pattern for the field name.
+
The schema exposes two types of fields: fixed fields, which have a declared name, and patterned fields, which have a declared pattern for the field name.
Patterned fields MUST have unique names within the containing object.
In order to preserve the ability to round-trip between YAML and JSON formats, YAML version 1.2 is RECOMMENDED along with some additional constraints:
Note: While APIs may be defined by OpenAPI documents in either YAML or JSON format, the API request and response bodies and other content are not required to be JSON or YAML.
-
4.3 Document Structure
-
An OpenAPI document MAY be made up of a single document or be divided into multiple, connected parts at the discretion of the author. In the latter case, Reference Objects and Schema Object$ref keywords are used.
-
It is RECOMMENDED that the root OpenAPI document be named: openapi.json or openapi.yaml.
-
4.4 Data Types
-
Data types in the OAS are based on the types supported by the JSON Schema Specification Draft 2020-12.
-Note that integer as a type is also supported and is defined as a JSON number without a fraction or exponent part.
-Models are defined using the Schema Object, which is a superset of JSON Schema Specification Draft 2020-12.
-
As defined by the JSON Schema Validation vocabulary, data types can have an optional modifier property: format.
-OAS defines additional formats to provide fine detail for primitive data types.
+
Note: While APIs may be described by OpenAPI Descriptions in either YAML or JSON format, the API request and response bodies and other content are not required to be JSON or YAML.
+
4.3 OpenAPI Description Structure
+
An OpenAPI Description (OAD) MAY be made up of a single JSON or YAML document or be divided into multiple, connected parts at the discretion of the author. In the latter case, Reference Object, Path Item Object and Schema Object$ref fields, as well as the Link ObjectoperationRef field, and the URI form of the Discriminator Objectmapping field, are used to identify the referenced elements.
+
In a multi-document OAD, the document containing the OpenAPI Object where parsing begins is known as that OAD’s entry document.
+
It is RECOMMENDED that the entry document of an OAD be named: openapi.json or openapi.yaml.
This includes a requirement to parse complete documents before deeming a Schema Object reference to be unresolvable, in order to detect keywords that might provide the reference target or impact the determination of the appropriate base URI.
+
Implementations MAY support complete-document parsing in any of the following ways:
+
+
Detecting OpenAPI or JSON Schema documents using media types
+
Detecting OpenAPI documents through the root openapi field
+
Detecting JSON Schema documents through detecting keywords or otherwise successfully parsing the document in accordance with the JSON Schema specification
+
Detecting a document containing a referenceable Object at its root based on the expected type of the reference
+
Allowing users to configure the type of documents that might be loaded due to a reference to a non-root Object
+
+
Implementations that parse referenced fragments of OpenAPI content without regard for the content of the rest of the containing document will miss keywords that change the meaning and behavior of the reference target.
+In particular, failing to take into account keywords that change the base URI introduces security risks by causing references to resolve to unintended URIs, with unpredictable results.
+While some implementations support this sort of parsing due to the requirements of past versions of this specification, in version 3.1, the result of parsing fragments in isolation is undefined and likely to contradict the requirements of this specification.
+
While it is possible to structure certain OpenAPI Descriptions to ensure that they will behave correctly when references are parsed as isolated fragments, depending on this is NOT RECOMMENDED.
+This specification does not explicitly enumerate the conditions under which such behavior is safe and provides no guarantee for continued safety in any future versions of the OAS.
+
A special case of parsing fragments of OAS content would be if such fragments are embedded in another format, referred to as an embedding format with respect to the OAS.
+Note that the OAS itself is an embedding format with respect to JSON Schema, which is embedded as Schema Objects.
+It is the responsibility of an embedding format to define how to parse embedded content, and OAS implementations that do not document support for an embedding format cannot be expected to parse embedded OAS content correctly.
+
4.3.2 Structural Interoperability
+
JSON or YAML objects within an OAD are interpreted as specific Objects (such as Operation Objects, Response Objects, Reference Objects, etc.) based on their context. Depending on how references are arranged, a given JSON or YAML object can be interpreted in multiple different contexts:
+
+
As the root object of the entry document, which is always interpreted as an OpenAPI Object
+
As the Object type implied by its parent Object within the document
+
As a reference target, with the Object type matching the reference source’s context
+
+
If the same JSON/YAML object is parsed multiple times and the respective contexts require it to be parsed as different Object types, the resulting behavior is implementation defined, and MAY be treated as an error if detected. An example would be referencing an empty Schema Object under #/components/schemas where a Path Item Object is expected, as an empty object is valid for both types. For maximum interoperability, it is RECOMMENDED that OpenAPI Description authors avoid such scenarios.
+
4.3.3 Resolving Implicit Connections
+
Several features of this specification require resolution of non-URI-based connections to some other part of the OpenAPI Description (OAD).
+
These connections are unambiguously resolved in single-document OADs, but the resolution process in multi-document OADs is implementation-defined, within the constraints described in this section.
+In some cases, an unambiguous URI-based alternative is available, and OAD authors are RECOMMENDED to always use the alternative:
A fifth implicit connection involves appending the templated URL paths of the Paths Object to the appropriate Server Object’s url field.
+This is unambiguous because only the entry document’s Paths Object contributes URLs to the described API.
+
It is RECOMMENDED to consider all Operation Objects from all parsed documents when resolving any Link Object operationId.
+This requires parsing all referenced documents prior to determining an operationId to be unresolvable.
+
The implicit connections in the Security Requirement Object and Discriminator Object rely on the component name, which is the name of the property holding the component in the appropriately typed sub-object of the Components Object.
+For example, the component name of the Schema Object at #/components/schemas/Foo is Foo.
+The implicit connection of tags in the Operation Object uses the name field of Tag Objects, which (like the Components Object) are found under the root OpenAPI Object.
+This means resolving component names and tag names both depend on starting from the correct OpenAPI Object.
+
For resolving component and tag name connections from a referenced (non-entry) document, it is RECOMMENDED that tools resolve from the entry document, rather than the current document.
+This allows Security Scheme Objects and Tag Objects to be defined next to the API’s deployment information (the top-level array of Server Objects), and treated as an interface for referenced documents to access.
+
The interface approach can also work for Discriminator Objects and Schema Objects, but it is also possible to keep the Discriminator Object’s behavior within a single document using the relative URI-reference syntax of mapping.
+
There are no URI-based alternatives for the Security Requirement Object or for the Operation Object’s tags field.
+These limitations are expected to be addressed in a future release.
+
See Appendix F: Resolving Security Requirements in a Referenced Document for an example of the possible resolutions, including which one is recommended by this section.
+The behavior for Discrimator Object non-URI mappings and for the Operation Object’s tags field operate on the same principles.
+
Note that no aspect of implicit connection resolution changes how URIs are resolved, or restricts their possible targets.
+
4.4 Data Types
+
Data types in the OAS are based on the types defined by the JSON Schema Validation Specification Draft 2020-12:
+“null”, “boolean”, “object”, “array”, “number”, “string”, or “integer”.
+Models are defined using the Schema Object, which is a superset of the JSON Schema Specification Draft 2020-12.
+
JSON Schema keywords and format values operate on JSON “instances” which may be one of the six JSON data types, “null”, “boolean”, “object”, “array”, “number”, or “string”, with certain keywords and formats only applying to a specific type. For example, the pattern keyword and the date-time format only apply to strings, and treat any instance of the other five types as automatically valid. This means JSON Schema keywords and formats do NOT implicitly require the expected type. Use the type keyword to explicitly constrain the type.
+
Note that the type keyword allows "integer" as a value for convenience, but keyword and format applicability does not recognize integers as being of a distinct JSON type from other numbers because JSON itself does not make that distinction. Since there is no distinct JSON integer type, JSON Schema defines integers mathematically. This means that both 1 and 1.0 are equivalent, and are both considered to be integers.
+
4.4.1 Data Type Format
+
As defined by the JSON Schema Validation specification, data types can have an optional modifier keyword: format. As described in that specification, format is treated as a non-validating annotation by default; the ability to validate format varies across implementations.
+
The OpenAPI Initiative also hosts a Format Registry for formats defined by OAS users and other specifications. Support for any registered format is strictly OPTIONAL, and support for one registered format does not imply support for any others.
+
Types that are not accompanied by a format keyword follow the type definition in the JSON Schema. Tools that do not recognize a specific formatMAY default back to the type alone, as if the format is not specified.
+For the purpose of JSON Schema validation, each format should specify the set of JSON data types for which it applies. In this registry, these types are shown in the “JSON Data Type” column.
As noted under Data Type, both type: number and type: integer are considered to be numbers in the data model.
+
4.4.2 Working with Binary Data
+
The OAS can describe either raw or encoded binary data.
+
+
raw binary is used where unencoded binary data is allowed, such as when sending a binary payload as the entire HTTP message body, or as part of a multipart/* payload that allows binary parts
+
encoded binary is used where binary data is embedded in a text-only format such as application/json or application/x-www-form-urlencoded (either as a message body or in the URL query string).
+
+
In the following table showing how to use Schema Object keywords for binary data, we use image/png as an example binary media type. Any binary media type, including application/octet-stream, is sufficient to indicate binary content.
Note that the encoding indicated by contentEncoding, which inflates the size of data in order to represent it as 7-bit ASCII text, is unrelated to HTTP’s Content-Encoding header, which indicates whether and how a message body has been compressed and is applied after all content serialization described in this section has occurred. Since HTTP allows unencoded binary message bodies, there is no standardized HTTP header for indicating base64 or similar encoding of an entire message body.
+
Using a contentEncoding of base64url ensures that URL encoding (as required in the query string and in message bodies of type application/x-www-form-urlencoded) does not need to further encode any part of the already-encoded binary data.
+
The contentMediaType keyword is redundant if the media type is already set:
If the Schema Object will be processed by a non-OAS-aware JSON Schema implementation, it may be useful to include contentMediaType even if it is redundant. However, if contentMediaType contradicts a relevant Media Type Object or Encoding Object, then contentMediaTypeSHALL be ignored.
+
The maxLength keyword MAY be used to set an expected upper bound on the length of a streaming payload. The keyword can be applied to either string data, including encoded binary data, or to unencoded binary data. For unencoded binary, the length is the number of octets.
+
4.4.2.1 Migrating binary descriptions from OAS 3.0
+
The following table shows how to migrate from OAS 3.0 binary data descriptions, continuing to use image/png as the example binary media type:
+
+
+
+
OAS < 3.1
+
OAS 3.1
+
Comments
+
+
+
+
+
type: string format: binary
+
contentMediaType: image/png
+
if redundant, can be omitted, often resulting in an empty Schema Object
note that base64url can be used to avoid re-encoding the base64 string to be URL-safe
-
4.5 Rich Text Formatting
+
4.5 Rich Text Formatting
Throughout the specification description fields are noted as supporting [CommonMark] markdown formatting.
-Where OpenAPI tooling renders rich text it MUST support, at a minimum, markdown syntax as described by [CommonMark-0.27]. Tooling MAY choose to ignore some CommonMark features to address security concerns.
-
4.6 Relative References in URIs
-
Unless specified otherwise, all properties that are URIs MAY be relative references as defined by [RFC3986] Section 4.2.
If a URI contains a fragment identifier, then the fragment should be resolved per the fragment resolution mechanism of the referenced document. If the representation of the referenced document is JSON or YAML, then the fragment identifier SHOULD be interpreted as a JSON-Pointer as per [RFC6901].
-
Relative references in Schema Objects, including any that appear as $id values, use the nearest parent $id as a Base URI, as described by JSON Schema Specification Draft 2020-12. If no parent schema contains an $id, then the Base URI MUST be determined according to [RFC3986] Section 5.1.
-
4.7 Relative References in URLs
-
Unless specified otherwise, all properties that are URLs MAY be relative references as defined by [RFC3986] Section 4.2.
-Unless specified otherwise, relative references are resolved using the URLs defined in the Server Object as a Base URL. Note that these themselves MAY be relative to the referring document.
-
4.8 Schema
+Where OpenAPI tooling renders rich text it MUST support, at a minimum, markdown syntax as described by [CommonMark-0.27]. Tooling MAY choose to ignore some CommonMark or extension features to address security concerns.
+
While the framing of CommonMark 0.27 as a minimum requirement means that tooling MAY choose to implement extensions on top of it, note that any such extensions are by definition implementation-defined and will not be interoperable.
+OpenAPI Description authors SHOULD consider how text using such extensions will be rendered by tools that offer only the minimum support.
+
4.6 Relative References in API Description URIs
+
URIs used as references within an OpenAPI Description, or to external documentation or other supplementary information such as a license, are resolved as identifiers, and described by this specification as URIs.
+As noted under Parsing Documents, this specification inherits JSON Schema Specification Draft 2020-12’s requirements for loading documents and associating them with their expected URIs, which might not match their current location.
+This feature is used both for working in development or test environments without having to change the URIs, and for working within restrictive network configurations or security policies.
+
Note that some URI fields are named url for historical reasons, but the descriptive text for those fields uses the correct “URI” terminology.
+
Unless specified otherwise, all fields that are URIs MAY be relative references as defined by [RFC3986] Section 4.2.
Relative URI references in other Objects, and in Schema Objects where no parent schema contains an $id, MUST be resolved using the referring document’s base URI, which is determined in accordance with [RFC3986] Section 5.1.2 – 5.1.4.
+In practice, this is usually the retrieval URI of the document, which MAY be determined based on either its current actual location or a user-supplied expected location.
+
If a URI contains a fragment identifier, then the fragment should be resolved per the fragment resolution mechanism of the referenced document. If the representation of the referenced document is JSON or YAML, then the fragment identifier SHOULD be interpreted as a JSON-Pointer as per [RFC6901].
+
Relative references in CommonMark hyperlinks are resolved in their rendered context, which might differ from the context of the API description.
+
4.7 Relative References in API URLs
+
API endpoints are by definition accessed as locations, and are described by this specification as URLs.
+
Unless specified otherwise, all fields that are URLs MAY be relative references as defined by [RFC3986] Section 4.2.
+Unless specified otherwise, relative references are resolved using the URLs defined in the Server Object as a Base URL. Note that these themselves MAY be relative to the referring document.
+
4.8 Schema
+
This section describes the structure of the OpenAPI Description format.
+This text is the only normative description of the format.
+A JSON Schema is hosted on spec.openapis.org for informational purposes.
+If the JSON Schema differs from this section, then this section MUST be considered authoritative.
In the following description, if a field is not explicitly REQUIRED or described with a MUST or SHALL, it can be considered OPTIONAL.
REQUIRED. This string MUST be the version number of the OpenAPI Specification that the OpenAPI document uses. The openapi field SHOULD be used by tooling to interpret the OpenAPI document. This is not related to the API info.version string.
+
REQUIRED. This string MUST be the version number of the OpenAPI Specification that the OpenAPI Document uses. The openapi field SHOULD be used by tooling to interpret the OpenAPI Document. This is not related to the API info.version string.
An array of Server Objects, which provide connectivity information to a target server. If the servers property is not provided, or is an empty array, the default value would be a Server Object with a url value of /.
+
An array of Server Objects, which provide connectivity information to a target server. If the servers field is not provided, or is an empty array, the default value would be a Server Object with a url value of /.
The incoming webhooks that MAY be received as part of this API and that the API consumer MAY choose to implement. Closely related to the callbacks feature, this section describes requests initiated other than by an API call, for example by an out of band registration. The key name is a unique string to refer to each webhook, while the (optionally referenced) Path Item Object describes a request that may be initiated by the API provider and the expected responses. An example is available.
A declaration of which security mechanisms can be used across the API. The list of values includes alternative security requirement objects that can be used. Only one of the security requirement objects need to be satisfied to authorize a request. Individual operations can override this definition. To make security optional, an empty security requirement ({}) can be included in the array.
+
A declaration of which security mechanisms can be used across the API. The list of values includes alternative Security Requirement Objects that can be used. Only one of the Security Requirement Objects need to be satisfied to authorize a request. Individual operations can override this definition. The list can be incomplete, up to being empty or absent. To make security explicitly optional, an empty security requirement ({}) can be included in the array.
A list of tags used by the document with additional metadata. The order of the tags can be used to reflect on their order by the parsing tools. Not all tags that are used by the Operation Object must be declared. The tags that are not declared MAY be organized randomly or based on the tools’ logic. Each tag name in the list MUST be unique.
+
A list of tags used by the OpenAPI Description with additional metadata. The order of the tags can be used to reflect on their order by the parsing tools. Not all tags that are used by the Operation Object must be declared. The tags that are not declared MAY be organized randomly or based on the tools’ logic. Each tag name in the list MUST be unique.
REQUIRED. The version of the OpenAPI document (which is distinct from the OpenAPI Specification version or the API implementation version).
+
REQUIRED. The version of the OpenAPI Document (which is distinct from the OpenAPI Specification version or the version of the API being described or the version of the OpenAPI Description).
{
- "title":"Sample Pet Store App",
+ "title":"Example Pet Store App","summary":"A pet store manager.",
- "description":"This is a sample server for a pet store.",
+ "description":"This is an example server for a pet store.","termsOfService":"https://example.com/terms/","contact":{"name":"API Support",
@@ -471,9 +684,9 @@
The identifying name of the contact person/organization.
-
url
+
url
string
-
The URL pointing to the contact information. This MUST be in the form of a URL.
+
The URI for the contact information. This MUST be in the form of a URI.
-
email
+
email
string
The email address of the contact person/organization. This MUST be in the form of an email address.
@@ -538,19 +751,19 @@
OpenAPI Specification v3.1.0
name
+
name
string
REQUIRED. The license name used for the API.
-
identifier
+
identifier
string
An [SPDX-Licenses] expression for the API. The identifier field is mutually exclusive of the url field.
-
url
+
url
string
-
A URL to the license used for the API. This MUST be in the form of a URL. The url field is mutually exclusive of the identifier field.
+
A URI for the license used for the API. This MUST be in the form of a URI. The url field is mutually exclusive of the identifier field.
@@ -577,19 +790,19 @@
OpenAPI Specification v3.1.0
url
+
url
string
-
REQUIRED. A URL to the target host. This URL supports Server Variables and MAY be relative, to indicate that the host location is relative to the location where the OpenAPI document is being served. Variable substitutions will be made when a variable is named in {brackets}.
+
REQUIRED. A URL to the target host. This URL supports Server Variables and MAY be relative, to indicate that the host location is relative to the location where the document containing the Server Object is being served. Variable substitutions will be made when a variable is named in {braces}.
-
description
+
description
string
An optional string describing the host designated by the URL. [CommonMark] syntax MAY be used for rich text representation.
The following shows how variables can be used for a server configuration:
{
@@ -639,13 +852,10 @@
OpenAPI Specification v3.1.0
"variables":{"username":{"default":"demo",
- "description":"this value is assigned by the service provider, in this example `gigantic-server.com`"
+ "description":"A user-specific subdomain. Use `demo` for a free sandbox environment."},"port":{
- "enum":[
- "8443",
- "443"
- ],
+ "enum":["8443","443"],"default":"8443"},"basePath":{
@@ -657,21 +867,21 @@
OpenAPI Specification v3.1.0
}
servers:
--url:https://{username}.gigantic-server.com:{port}/{basePath}
- description:TheproductionAPIserver
- variables:
- username:
- # note! no enum here means it is an open value
- default:demo
- description:thisvalueisassignedbytheserviceprovider,inthisexample`gigantic-server.com`
- port:
- enum:
- -'8443'
- -'443'
- default:'8443'
- basePath:
- # open meaning there is the opportunity to use special base paths as assigned by the provider, default is `v2`
- default:v2
+ -url:https://{username}.gigantic-server.com:{port}/{basePath}
+ description:TheproductionAPIserver
+ variables:
+ username:
+ # note! no enum here means it is an open value
+ default:demo
+ description:Auser-specificsubdomain.Use`demo`forafreesandboxenvironment.
+ port:
+ enum:
+ -'8443'
+ -'443'
+ default:'8443'
+ basePath:
+ # open meaning there is the opportunity to use special base paths as assigned by the provider, default is `v2`
+ default:v2
4.8.6 Server Variable Object
An object representing a Server Variable for server URL template substitution.
@@ -686,17 +896,17 @@
OpenAPI Specification v3.1.0
enum
+
enum
[string]
An enumeration of string values to be used if the substitution options are from a limited set. The array MUST NOT be empty.
-
default
+
default
string
-
REQUIRED. The default value to use for substitution, which SHALL be sent if an alternate value is not supplied. Note this behavior is different than the Schema Object’s treatment of default values, because in those cases parameter values are optional. If the enum is defined, the value MUST exist in the enum’s values.
+
REQUIRED. The default value to use for substitution, which SHALL be sent if an alternate value is not supplied. If the enum is defined, the value MUST exist in the enum’s values. Note that this behavior is different from the Schema Object’s default keyword, which documents the receiver’s behavior rather than inserting the value into the data.
-
description
+
description
string
An optional description for the server variable. [CommonMark] syntax MAY be used for rich text representation.
Holds a set of reusable objects for different aspects of the OAS.
-All objects defined within the components object will have no effect on the API unless they are explicitly referenced from properties outside the components object.
+All objects defined within the Components Object will have no effect on the API unless they are explicitly referenced from outside the Components Object.
Holds the relative paths to the individual endpoints and their operations.
-The path is appended to the URL from the Server Object in order to construct the full URL. The Paths MAY be empty, due to Access Control List (ACL) constraints.
A relative path to an individual endpoint. The field name MUST begin with a forward slash (/). The path is appended (no relative URL resolution) to the expanded URL from the Server Object’s url field in order to construct the full URL. Path templating is allowed. When matching URLs, concrete (non-templated) paths would be matched before their templated counterparts. Templated paths with the same hierarchy but different templated names MUST NOT exist as they are identical. In case of ambiguous matching, it’s up to the tooling to decide which one to use.
+
A relative path to an individual endpoint. The field name MUST begin with a forward slash (/). The path is appended (no relative URL resolution) to the expanded URL from the Server Object’s url field in order to construct the full URL. Path templating is allowed. When matching URLs, concrete (non-templated) paths would be matched before their templated counterparts. Templated paths with the same hierarchy but different templated names MUST NOT exist as they are identical. In case of ambiguous matching, it’s up to the tooling to decide which one to use.
@@ -986,7 +1196,7 @@
OpenAPI Specification v3.1.0
"get":{"description":"Returns all pets from the system that the user has access to","responses":{
- "200":{
+ "200":{"description":"A list of pets.","content":{"application/json":{
@@ -1032,69 +1242,69 @@
OpenAPI Specification v3.1.0
$ref
+
$ref
string
-
Allows for a referenced definition of this path item. The referenced structure MUST be in the form of a Path Item Object. In case a Path Item Object field appears both in the defined object and the referenced object, the behavior is undefined. See the rules for resolving Relative References.
+
Allows for a referenced definition of this path item. The value MUST be in the form of a URI, and the referenced structure MUST be in the form of a Path Item Object. In case a Path Item Object field appears both in the defined object and the referenced object, the behavior is undefined. See the rules for resolving Relative References.
Note: The behavior of $ref with adjacent properties is likely to change in future versions of this specification to bring it into closer alignment with the behavior of the Reference Object.
-
summary
+
summary
string
-
An optional, string summary, intended to apply to all operations in this path.
+
An optional string summary, intended to apply to all operations in this path.
-
description
+
description
string
-
An optional, string description, intended to apply to all operations in this path. [CommonMark] syntax MAY be used for rich text representation.
+
An optional string description, intended to apply to all operations in this path. [CommonMark] syntax MAY be used for rich text representation.
An alternative server array to service all operations in this path.
+
An alternative servers array to service all operations in this path. If a servers array is specified at the OpenAPI Object level, it will be overridden by this value.
A list of parameters that are applicable for all the operations described under this path. These parameters can be overridden at the operation level, but cannot be removed there. The list MUST NOT include duplicated parameters. A unique parameter is defined by a combination of a name and location. The list can use the Reference Object to link to parameters that are defined at the OpenAPI Object’s components/parameters.
+
A list of parameters that are applicable for all the operations described under this path. These parameters can be overridden at the operation level, but cannot be removed there. The list MUST NOT include duplicated parameters. A unique parameter is defined by a combination of a name and location. The list can use the Reference Object to link to parameters that are defined in the OpenAPI Object’s components.parameters.
Additional external documentation for this operation.
-
operationId
+
operationId
string
Unique string used to identify the operation. The id MUST be unique among all operations described in the API. The operationId value is case-sensitive. Tools and libraries MAY use the operationId to uniquely identify an operation, therefore, it is RECOMMENDED to follow common programming naming conventions.
A list of parameters that are applicable for this operation. If a parameter is already defined at the Path Item, the new definition will override it but can never remove it. The list MUST NOT include duplicated parameters. A unique parameter is defined by a combination of a name and location. The list can use the Reference Object to link to parameters that are defined at the OpenAPI Object’s components/parameters.
+
A list of parameters that are applicable for this operation. If a parameter is already defined at the Path Item, the new definition will override it but can never remove it. The list MUST NOT include duplicated parameters. A unique parameter is defined by a combination of a name and location. The list can use the Reference Object to link to parameters that are defined in the OpenAPI Object’s components.parameters.
The request body applicable for this operation. The requestBody is fully supported in HTTP methods where the HTTP 1.1 specification [RFC7231] Section 4.3.1 has explicitly defined semantics for request bodies. In other cases where the HTTP spec is vague (such as GET, HEAD and DELETE), requestBody is permitted but does not have well-defined semantics and SHOULD be avoided if possible.
+
The request body applicable for this operation. The requestBody is fully supported in HTTP methods where the HTTP 1.1 specification [RFC7231] Section 4.3.1 has explicitly defined semantics for request bodies. In other cases where the HTTP spec is vague (such as GET, HEAD and DELETE), requestBody is permitted but does not have well-defined semantics and SHOULD be avoided if possible.
A map of possible out-of band callbacks related to the parent operation. The key is a unique identifier for the Callback Object. Each value in the map is a Callback Object that describes a request that may be initiated by the API provider and the expected responses.
-
deprecated
+
deprecated
boolean
Declares this operation to be deprecated. Consumers SHOULD refrain from usage of the declared operation. Default value is false.
A declaration of which security mechanisms can be used for this operation. The list of values includes alternative security requirement objects that can be used. Only one of the security requirement objects need to be satisfied to authorize a request. To make security optional, an empty security requirement ({}) can be included in the array. This definition overrides any declared top-level security. To remove a top-level security declaration, an empty array can be used.
+
A declaration of which security mechanisms can be used for this operation. The list of values includes alternative Security Requirement Objects that can be used. Only one of the Security Requirement Objects need to be satisfied to authorize a request. To make security optional, an empty security requirement ({}) can be included in the array. This definition overrides any declared top-level security. To remove a top-level security declaration, an empty array can be used.
An alternative server array to service this operation. If an alternative server object is specified at the Path Item Object or Root level, it will be overridden by this value.
+
An alternative servers array to service this operation. If a servers array is specified at the Path Item Object or OpenAPI Object level, it will be overridden by this value.
{
- "tags":[
- "pet"
- ],
+ "tags":["pet"],"summary":"Updates a pet in the store with form data","operationId":"updatePetWithForm","parameters":[
@@ -1309,54 +1517,51 @@
Allows referencing an external resource for extended documentation.
@@ -1371,14 +1576,14 @@
OpenAPI Specification v3.1.0
description
+
description
string
A description of the target documentation. [CommonMark] syntax MAY be used for rich text representation.
-
url
+
url
string
-
REQUIRED. The URL for the target documentation. This MUST be in the form of a URL.
+
REQUIRED. The URI for the target documentation. This MUST be in the form of a URI.
@@ -1394,16 +1599,22 @@
OpenAPI Specification v3.1.0
4.8.12 Parameter Object
Describes a single operation parameter.
-
A unique parameter is defined by a combination of a name and location.
+
A unique parameter is defined by a combination of a name and location.
+
See Appendix E for a detailed examination of percent-encoding concerns, including interactions with the application/x-www-form-urlencoded query string format.
4.8.12.1 Parameter Locations
There are four possible parameter locations specified by the in field:
path - Used together with Path Templating, where the parameter value is actually part of the operation’s URL. This does not include the host or base path of the API. For example, in /items/{itemId}, the path parameter is itemId.
query - Parameters that are appended to the URL. For example, in /items?id=###, the query parameter is id.
-
header - Custom headers that are expected as part of the request. Note that [RFC7230] Page 22 states header names are case insensitive.
+
header - Custom headers that are expected as part of the request. Note that [RFC7230] Section 3.2 states header names are case insensitive.
cookie - Used to pass a specific cookie value to the API.
4.8.12.2 Fixed Fields
+
The rules for serialization of the parameter are specified in one of two ways.
+Parameter Objects MUST include either a content field or a schema field, but not both.
+See Appendix B for a discussion of converting values of various types to string representations.
+
4.8.12.2.1 Common Fixed Fields
+
These fields MAY be used with either content or schema.
@@ -1414,39 +1625,44 @@
OpenAPI Specification v3.1.0
name
+
name
string
-
REQUIRED. The name of the parameter. Parameter names are case sensitive.
If in is "path", the name field MUST correspond to a template expression occurring within the path field in the Paths Object. See Path Templating for further information.
If in is "header" and the name field is "Accept", "Content-Type" or "Authorization", the parameter definition SHALL be ignored.
For all other cases, the name corresponds to the parameter name used by the in property.
+
REQUIRED. The name of the parameter. Parameter names are case sensitive.
If in is "path", the name field MUST correspond to a template expression occurring within the path field in the Paths Object. See Path Templating for further information.
If in is "header" and the name field is "Accept", "Content-Type" or "Authorization", the parameter definition SHALL be ignored.
For all other cases, the name corresponds to the parameter name used by the in field.
-
in
+
in
string
REQUIRED. The location of the parameter. Possible values are "query", "header", "path" or "cookie".
-
description
+
description
string
A brief description of the parameter. This could contain examples of use. [CommonMark] syntax MAY be used for rich text representation.
-
required
+
required
boolean
-
Determines whether this parameter is mandatory. If the parameter location is "path", this property is REQUIRED and its value MUST be true. Otherwise, the property MAY be included and its default value is false.
+
Determines whether this parameter is mandatory. If the parameter location is "path", this field is REQUIRED and its value MUST be true. Otherwise, the field MAY be included and its default value is false.
-
deprecated
+
deprecated
boolean
Specifies that a parameter is deprecated and SHOULD be transitioned out of usage. Default value is false.
-
allowEmptyValue
+
allowEmptyValue
boolean
-
Sets the ability to pass empty-valued parameters. This is valid only for query parameters and allows sending a parameter with an empty value. Default value is false. If style is used, and if behavior is n/a (cannot be serialized), the value of allowEmptyValueSHALL be ignored. Use of this property is NOT RECOMMENDED, as it is likely to be removed in a later revision.
+
If true, clients MAY pass a zero-length string value in place of parameters that would otherwise be omitted entirely, which the server SHOULD interpret as the parameter being unused. Default value is false. If style is used, and if behavior is n/a (cannot be serialized), the value of allowEmptyValueSHALL be ignored. Interactions between this field and the parameter’s Schema Object are implementation-defined. This field is valid only for query parameters. Use of this field is NOT RECOMMENDED, and it is likely to be removed in a later revision.
-
The rules for serialization of the parameter are specified in one of two ways.
-For simpler scenarios, a schema and style can describe the structure and syntax of the parameter.
Note that while "Cookie" as a name is not forbidden if in is "header", the effect of defining a cookie parameter that way is undefined; use in: "cookie" instead.
+
4.8.12.2.2 Fixed Fields for use with schema
+
For simpler scenarios, a schema and style can describe the structure and syntax of the parameter.
+When example or examples are provided in conjunction with the schema field, the example SHOULD match the specified schema and follow the prescribed serialization strategy for the parameter.
+The example and examples fields are mutually exclusive, and if either is present it SHALLoverride any example in the schema.
+
Serializing with schema is NOT RECOMMENDED for in: "cookie" parameters, in: "header" parameters that use HTTP header parameters (name=value pairs following a ;) in their values, or in: "header" parameters where values might have non-URL-safe characters; see Appendix D for details.
@@ -1457,40 +1673,41 @@
OpenAPI Specification v3.1.0
style
+
style
string
-
Describes how the parameter value will be serialized depending on the type of the parameter value. Default values (based on value of in): for query - form; for path - simple; for header - simple; for cookie - form.
+
Describes how the parameter value will be serialized depending on the type of the parameter value. Default values (based on value of in): for "query" - "form"; for "path" - "simple"; for "header" - "simple"; for "cookie" - "form".
-
explode
+
explode
boolean
-
When this is true, parameter values of type array or object generate separate parameters for each value of the array or key-value pair of the map. For other types of parameters this property has no effect. When style is form, the default value is true. For all other styles, the default value is false.
+
When this is true, parameter values of type array or object generate separate parameters for each value of the array or key-value pair of the map. For other types of parameters this field has no effect. When style is "form", the default value is true. For all other styles, the default value is false. Note that despite false being the default for deepObject, the combination of false with deepObject is undefined.
-
allowReserved
+
allowReserved
boolean
-
Determines whether the parameter value SHOULD allow reserved characters, as defined by [RFC3986] Section 2.2:/?#[]@!$&'()*+,;= to be included without percent-encoding. This property only applies to parameters with an in value of query. The default value is false.
+
When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570] Section 3.2.3, which allows RFC3986’s reserved character set, as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including % outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are not allowed in the query string ([, ], #), or have a special meaning in application/x-www-form-urlencoded (-, &, +); see Appendices C and E for details. This field only applies to parameters with an in value of query. The default value is false.
The schema defining the type used for the parameter.
-
example
+
example
Any
-
Example of the parameter’s potential value. The example SHOULD match the specified schema and encoding properties if present. The example field is mutually exclusive of the examples field. Furthermore, if referencing a schema that contains an example, the example value SHALLoverride the example provided by the schema. To represent examples of media types that cannot naturally be represented in JSON or YAML, a string value can contain the example with escaping where necessary.
Examples of the parameter’s potential value. Each example SHOULD contain a value in the correct format as specified in the parameter encoding. The examples field is mutually exclusive of the example field. Furthermore, if referencing a schema that contains an example, the examples value SHALLoverride the example provided by the schema.
For more complex scenarios, the content property can define the media type and schema of the parameter.
-A parameter MUST contain either a schema property, or a content property, but not both.
-When example or examples are provided in conjunction with the schema object, the example MUST follow the prescribed serialization strategy for the parameter.
For more complex scenarios, the content field can define the media type and schema of the parameter, as well as give examples of its use.
+Using content with a text/plain media type is RECOMMENDED for in: "header" and in: "cookie" parameters where the schema strategy is not appropriate.
Simple style parameters defined by [RFC6570] Section 3.2.2. This option replaces collectionFormat with a csv value from OpenAPI 2.0.
+
+
form
primitive, array, object
query, cookie
Form style parameters defined by [RFC6570] Section 3.2.8. This option replaces collectionFormat with a csv (when explode is false) or multi (when explode is true) value from OpenAPI 2.0.
-
simple
-
array
-
path, header
-
Simple style parameters defined by [RFC6570] Section 3.2.2. This option replaces collectionFormat with a csv value from OpenAPI 2.0.
-
-
spaceDelimited
array, object
query
-
Space separated array or object values. This option replaces collectionFormat equal to ssv from OpenAPI 2.0.
+
Space separated array values or object properties and values. This option replaces collectionFormat equal to ssv from OpenAPI 2.0.
pipeDelimited
array, object
query
-
Pipe separated array or object values. This option replaces collectionFormat equal to pipes from OpenAPI 2.0.
+
Pipe separated array values or object properties and values. This option replaces collectionFormat equal to pipes from OpenAPI 2.0.
deepObject
object
query
-
Provides a simple way of rendering nested objects using form parameters.
+
Allows objects with scalar properties to be represented using form parameters. The representation of array or object properties is not defined.
+
See Appendix E for a discussion of percent-encoding, including when delimiters need to be percent-encoded and options for handling collisions with percent-encoded data.
4.8.12.4 Style Examples
Assume a parameter named color has one of the following values:
The following table shows examples of rendering differences for each value.
+
The following table shows examples, as would be shown with the example or examples keywords, of the different serializations for each value.
+
+
The value empty denotes the empty string, and is unrelated to the allowEmptyValue field
+
The behavior of combinations marked n/a is undefined
+
The undefined column replaces the empty column in previous versions of this specification in order to better align with [RFC6570] Section 2.3 terminology, which describes certain values including but not limited to null as “undefined” values with special handling; notably, the empty string is not undefined
+
For form and the non-RFC6570 query string styles spaceDelimited, pipeDelimited, and deepObject, each example is shown prefixed with ? as if it were the only query parameter; see Appendix C for more information on constructing query strings from multiple parameters, and Appendix D for warnings regarding form and cookie parameters
+
Note that the ? prefix is not appropriate for serializing application/x-www-form-urlencoded HTTP message bodies, and MUST be stripped or (if constructing the string manually) not added when used in that context; see the Encoding Object for more information
+
The examples are percent-encoded as required by RFC6570 and RFC3986; see Appendix E for a thorough discussion of percent-encoding concerns, including why unencoded | (%7C), [ (%5B), and ] (%5D) seem to work in some environments despite not being compliant.
REQUIRED. The content of the request body. The key is a media type or media type range, see [RFC7231] Appendix D, and the value describes it. For requests that match multiple keys, only the most specific key is applicable. e.g. text/plain overrides text/*
+
REQUIRED. The content of the request body. The key is a media type or media type range, see [RFC7231] Appendix D, and the value describes it. For requests that match multiple keys, only the most specific key is applicable. e.g. "text/plain" overrides "text/*"
-
required
+
required
boolean
Determines if the request body is required in the request. Defaults to false.
Each Media Type Object provides schema and examples for the media type identified by its key.
+
When example or examples are provided, the example SHOULD match the specified schema and be in the correct format as specified by the media type and its encoding.
+The example and examples fields are mutually exclusive, and if either is present it SHALLoverride any example in the schema.
+See Working With Examples for further guidance regarding the different ways of specifying examples, including non-JSON/YAML values.
The schema defining the content of the request, response, or parameter.
+
The schema defining the content of the request, response, parameter, or header.
-
example
+
example
Any
-
Example of the media type. The example object SHOULD be in the correct format as specified by the media type. The example field is mutually exclusive of the examples field. Furthermore, if referencing a schema which contains an example, the example value SHALLoverride the example provided by the schema.
Examples of the media type. Each example object SHOULD match the media type and specified schema if present. The examples field is mutually exclusive of the example field. Furthermore, if referencing a schema which contains an example, the examples value SHALLoverride the example provided by the schema.
A map between a property name and its encoding information. The key, being the property name, MUST exist in the schema as a property. The encoding object SHALL only apply to requestBody objects when the media type is multipart or application/x-www-form-urlencoded.
+
A map between a property name and its encoding information. The key, being the property name, MUST exist in the schema as a property. The encoding field SHALL only apply to Request Body Objects, and only when the media type is multipart or application/x-www-form-urlencoded. If no Encoding Object is provided for a property, the behavior is determined by the default values documented for the Encoding Object.
In contrast with the 2.0 specification, file input/output content in OpenAPI is described with the same semantics as any other schema type.
-
In contrast with the 3.0 specification, the format keyword has no effect on the content-encoding of the schema. JSON Schema offers a contentEncoding keyword, which may be used to specify the Content-Encoding for the schema. The contentEncoding keyword supports all encodings defined in [RFC4648], including “base64” and “base64url”, as well as “quoted-printable” from [RFC2045] Section 6.7. The encoding specified by the contentEncoding keyword is independent of an encoding specified by the Content-Type header in the request or response or metadata of a multipart body – when both are present, the encoding specified in the contentEncoding is applied first and then the encoding specified in the Content-Type header.
-
JSON Schema also offers a contentMediaType keyword. However, when the media type is already specified by the Media Type Object’s key, or by the contentType field of an Encoding Object, the contentMediaType keyword SHALL be ignored if present.
+
In contrast to OpenAPI 2.0, file input/output content in OAS 3.x is described with the same semantics as any other schema type.
+
In contrast to OAS 3.0, the format keyword has no effect on the content-encoding of the schema in OAS 3.1. Instead, JSON Schema’s contentEncoding and contentMediaType keywords are used. See Working With Binary Data for how to model various scenarios with these keywords, and how to migrate from the previous format usage.
Examples:
Content transferred in binary (octet-stream) MAY omit schema:
# a PNG image as a binary file:content:
- image/png: {}
+ image/png: {}
# arbitrary JSON without constraints beyond being syntactically valid:
+content:
+ application/json: {}
-
Note that the Content-Type remains image/png, describing the semantics of the payload. The JSON Schema type and contentEncoding fields explain that the payload is transferred as text. The JSON Schema contentMediaType is technically redundant, but can be used by JSON Schema tools that may not be aware of the OpenAPI context.
These examples apply to either input payloads of file uploads or response payloads.
A requestBody for submitting a file in a POST operation may look like the following example:
requestBody:
@@ -2065,82 +2282,20 @@
OpenAPI Specification v3.1.0
image/jpeg: {}
image/png: {}
-
To upload multiple files, a multipart media type MUST be used:
-
requestBody:
- content:
- multipart/form-data:
- schema:
- properties:
- # The property name 'file' will be used for all files.
- file:
- type:array
- items: {}
-
-
As seen in the section on multipart/form-data below, the empty schema for items indicates a media type of application/octet-stream.
In this example, the contents in the requestBodyMUST be stringified per [RFC1866] when passed to the server. In addition, the address field complex object will be stringified.
-
When passing complex objects in the application/x-www-form-urlencoded content type, the default serialization strategy of such properties is described in the Encoding Object’s style property as form.
4.8.14.5 Special Considerations for multipart Content
-
It is common to use multipart/form-data as a Content-Type when transferring request bodies to operations. In contrast to 2.0, a schema is REQUIRED to define the input parameters to the operation when using multipart content. This supports complex structures as well as supporting mechanisms for multiple file uploads.
-
In a multipart/form-data request body, each schema property, or each element of a schema array property, takes a section in the payload with an internal header as defined by [RFC7578]. The serialization strategy for each property of a multipart/form-data request body can be specified in an associated Encoding Object.
-
When passing in multipart types, boundaries MAY be used to separate sections of the content being transferred – thus, the following default Content-Types are defined for multipart:
-
-
If the property is a primitive, or an array of primitive values, the default Content-Type is text/plain
-
If the property is complex, or an array of complex values, the default Content-Type is application/json
-
If the property is a type: string with a contentEncoding, the default Content-Type is application/octet-stream
-
-
Per the JSON Schema specification, contentMediaType without contentEncoding present is treated as if contentEncoding: identity were present. While useful for embedding text documents such as text/html into JSON strings, it is not useful for a multipart/form-data part, as it just causes the document to be treated as text/plain instead of its actual media type. Use the Encoding Object without contentMediaType if no contentEncoding is required.
-
Examples:
-
requestBody:
- content:
- multipart/form-data:
- schema:
- type:object
- properties:
- id:
- type:string
- format:uuid
- address:
- # default Content-Type for objects is `application/json`
- type:object
- properties: {}
- profileImage:
- # Content-Type for application-level encoded resource is `text/plain`
- type:string
- contentMediaType:image/png
- contentEncoding:base64
- children:
- # default Content-Type for arrays is based on the _inner_ type (`text/plain` here)
- type:array
- items:
- type:string
- addresses:
- # default Content-Type for arrays is based on the _inner_ type (object shown, so `application/json` in this example)
- type:array
- items:
- type:object
- $ref:'#/components/schemas/Address'
-
-
An encoding attribute is introduced to give you control over the serialization of parts of multipart request bodies. This attribute is only applicable to multipart and application/x-www-form-urlencoded request bodies.
A single encoding definition applied to a single schema property.
+
A single encoding definition applied to a single schema property.
+See Appendix B for a discussion of converting values of various types to string representations.
+
Properties are correlated with multipart parts using the name parameter of Content-Disposition: form-data, and with application/x-www-form-urlencoded using the query string parameter names.
+In both cases, their order is implementation-defined.
+
See Appendix E for a detailed examination of percent-encoding concerns for form media types.
4.8.15.1 Fixed Fields
+
4.8.15.1.1 Common Fixed Fields
+
These fields MAY be used either with or without the RFC6570-style serialization fields defined in the next section below.
@@ -2151,60 +2306,226 @@
OpenAPI Specification v3.1.0
contentType
+
contentType
string
-
The Content-Type for encoding a specific property. Default value depends on the property type: for object - application/json; for array – the default is defined based on the inner type; for all other cases the default is application/octet-stream. The value can be a specific media type (e.g. application/json), a wildcard media type (e.g. image/*), or a comma-separated list of the two types.
+
The Content-Type for encoding a specific property. The value is a comma-separated list, each element of which is either a specific media type (e.g. image/png) or a wildcard media type (e.g. image/*). Default value depends on the property type as shown in the table below.
A map allowing additional information to be provided as headers, for example Content-Disposition. Content-Type is described separately and SHALL be ignored in this section. This property SHALL be ignored if the request body media type is not a multipart.
+
A map allowing additional information to be provided as headers. Content-Type is described separately and SHALL be ignored in this section. This field SHALL be ignored if the request body media type is not a multipart.
The default values for contentType are as follows, where an n/a in the contentEncoding column means that the presence or value of contentEncoding is irrelevant:
+
+
-
style
-
string
-
Describes how a specific property value will be serialized depending on its type. See Parameter Object for details on the style property. The behavior follows the same values as query parameters, including default values. This property SHALL be ignored if the request body media type is not application/x-www-form-urlencoded or multipart/form-data. If a value is explicitly defined, then the value of contentType (implicit or explicit) SHALL be ignored.
+
type
+
contentEncoding
+
Default contentType
+
+
-
explode
-
boolean
-
When this is true, property values of type array or object generate separate parameters for each value of the array, or key-value-pair of the map. For other types of properties this property has no effect. When style is form, the default value is true. For all other styles, the default value is false. This property SHALL be ignored if the request body media type is not application/x-www-form-urlencoded or multipart/form-data. If a value is explicitly defined, then the value of contentType (implicit or explicit) SHALL be ignored.
Determines whether the parameter value SHOULD allow reserved characters, as defined by [RFC3986] Section 2.2:/?#[]@!$&'()*+,;= to be included without percent-encoding. The default value is false. This property SHALL be ignored if the request body media type is not application/x-www-form-urlencoded or multipart/form-data. If a value is explicitly defined, then the value of contentType (implicit or explicit) SHALL be ignored.
Determining how to handle a type value of null depends on how null values are being serialized.
+If null values are entirely omitted, then the contentType is irrelevant.
+See Appendix B for a discussion of data type conversion options.
+
4.8.15.1.2 Fixed Fields for RFC6570-style Serialization
+
+
+
+
Field Name
+
Type
+
Description
+
+
+
+
+
style
+
string
+
Describes how a specific property value will be serialized depending on its type. See Parameter Object for details on the style field. The behavior follows the same values as query parameters, including default values. Note that the initial ? used in query strings is not used in application/x-www-form-urlencoded message bodies, and MUST be removed (if using an RFC6570 implementation) or simply not added (if constructing the string manually). This field SHALL be ignored if the request body media type is not application/x-www-form-urlencoded or multipart/form-data. If a value is explicitly defined, then the value of contentType (implicit or explicit) SHALL be ignored.
+
+
+
explode
+
boolean
+
When this is true, property values of type array or object generate separate parameters for each value of the array, or key-value-pair of the map. For other types of properties this field has no effect. When style is "form", the default value is true. For all other styles, the default value is false. Note that despite false being the default for deepObject, the combination of false with deepObject is undefined. This field SHALL be ignored if the request body media type is not application/x-www-form-urlencoded or multipart/form-data. If a value is explicitly defined, then the value of contentType (implicit or explicit) SHALL be ignored.
+
+
+
allowReserved
+
boolean
+
When this is true, parameter values are serialized using reserved expansion, as defined by [RFC6570] Section 3.2.3, which allows RFC3986’s reserved character set, as well as percent-encoded triples, to pass through unchanged, while still percent-encoding all other disallowed characters (including % outside of percent-encoded triples). Applications are still responsible for percent-encoding reserved characters that are not allowed in the query string ([, ], #), or have a special meaning in application/x-www-form-urlencoded (-, &, +); see Appendices C and E for details. The default value is false. This field SHALL be ignored if the request body media type is not application/x-www-form-urlencoded or multipart/form-data. If a value is explicitly defined, then the value of contentType (implicit or explicit) SHALL be ignored.
+
+
+
+
See also Appendix C: Using RFC6570 Implementations for additional guidance, including on difficulties caused by the interaction between RFC6570’s percent-encoding rules and the multipart/form-data media type.
+
Note that the presence of at least one of style, explode, or allowReserved with an explicit value is equivalent to using schema with in: "query" Parameter Objects.
+The absence of all three of those fields is the equivalent of using content, but with the media type specified in contentType rather than through a Media Type Object.
+
4.8.15.2 Encoding the x-www-form-urlencoded Media Type
+
To submit content using form url encoding via [RFC1866], use the application/x-www-form-urlencoded media type in the Media Type Object under the Request Body Object.
+This configuration means that the request body MUST be encoded per [RFC1866] when passed to the server, after any complex objects have been serialized to a string representation.
+
See Appendix E for a detailed examination of percent-encoding concerns for form media types.
+
4.8.15.2.1 Example: URL Encoded Form with JSON Values
+
When there is no encoding field, the serialization strategy is based on the Encoding Object’s default values:
+
requestBody:content:
- multipart/form-data:
+ application/x-www-form-urlencoded:schema:type:objectproperties:id:
- # default is text/plaintype:stringformat:uuidaddress:
- # default is application/json
- type:object
- properties: {}
- historyMetadata:
- # need to declare XML format!
- description:metadatainXMLformat
+ # complex types are stringified to support RFC 1866type:objectproperties: {}
- profileImage: {}
+
+
With this example, consider an id of f81d4fae-7dec-11d0-a765-00a0c91e6bf6 and a US-style address (with ZIP+4) as follows:
Assuming the most compact representation of the JSON value (with unnecessary whitespace removed), we would expect to see the following request body, where space characters have been replaced with + and +, ", {, and } have been percent-encoded to %2B, %22, %7B, and %7D, respectively:
Note that the id keyword is treated as text/plain per the Encoding Object’s default behavior, and is serialized as-is.
+If it were treated as application/json, then the serialized value would be a JSON string including quotation marks, which would be percent-encoded as %22.
+
Here is the id parameter (without address) serialized as application/json instead of text/plain, and then encoded per RFC1866:
+
id=%22f81d4fae-7dec-11d0-a765-00a0c91e6bf6%22
+
+
4.8.15.2.2 Example: URL Encoded Form with Binary Values
+
Note that application/x-www-form-urlencoded is a text format, which requires base64-encoding any binary data:
+
requestBody:
+ content:
+ application/x-www-form-urlencoded:
+ schema:
+ type:object
+ properties:
+ name:
+ type:string
+ icon:
+ # The default with "contentEncoding" is application/octet-stream,
+ # so we need to set image media type(s) in the Encoding Object.
+ type:string
+ contentEncoding:base64url
+ encoding:
+ icon:
+ contentType:image/png,image/jpeg
+
+
Given a name of example and a solid red 2x2-pixel PNG for icon, this
+would produce a request body of:
Note that the = padding characters at the end need to be percent-encoded, even with the “URL safe” contentEncoding: base64url.
+Some base64-decoding implementations may be able to use the string without the padding per [RFC4648] Section 3.2.
+However, this is not guaranteed, so it may be more interoperable to keep the padding and rely on percent-decoding.
+
4.8.15.3 Encoding multipart Media Types
+
It is common to use multipart/form-data as a Content-Type when transferring forms as request bodies. In contrast to OpenAPI 2.0, a schema is REQUIRED to define the input parameters to the operation when using multipart content. This supports complex structures as well as supporting mechanisms for multiple file uploads.
+
The form-data disposition and its name parameter are mandatory for multipart/form-data ([RFC7578] Section 4.2).
+Array properties are handled by applying the same name to multiple parts, as is recommended by [RFC7578] Section 4.3 for supplying multiple values per form field.
+See [RFC7578] Section 5 for guidance regarding non-ASCII part names.
+
Various other multipart types, most notable multipart/mixed ([RFC2046] Section 5.1.3) neither require nor forbid specific Content-Disposition values, which means care must be taken to ensure that any values used are supported by all relevant software.
+It is not currently possible to correlate schema properties with unnamed, ordered parts in media types such as multipart/mixed, but implementations MAY choose to support such types when Content-Disposition: form-data is used with a name parameter.
+
Note that there are significant restrictions on what headers can be used with multipart media types in general ([RFC2046] Section 5.1) and multi-part/form-data in particular ([RFC7578] Section 4.8).
+
Note also that Content-Transfer-Encoding is deprecated for multipart/form-data ([RFC7578] Section 4.7) where binary data is supported, as it is in HTTP.
+
+Using contentEncoding for a multipart field is equivalent to specifying an Encoding Object with a headers field containing Content-Transfer-Encoding with a schema that requires the value used in contentEncoding.
++If contentEncoding is used for a multipart field that has an Encoding Object with a headers field containing Content-Transfer-Encoding with a schema that disallows the value from contentEncoding, the result is undefined for serialization and parsing.
+
Note that as stated in Working with Binary Data, if the Encoding Object’s contentType, whether set explicitly or implicitly through its default value rules, disagrees with the contentMediaType in a Schema Object, the contentMediaTypeSHALL be ignored.
+Because of this, and because the Encoding Object’s contentType defaulting rules do not take the Schema Object’scontentMediaType into account, the use of contentMediaType with an Encoding Object is NOT RECOMMENDED.
+
See Appendix E for a detailed examination of percent-encoding concerns for form media types.
+
4.8.15.3.1 Example: Basic Multipart Form
+
When the encoding field is not used, the encoding is determined by the Encoding Object’s defaults:
+
requestBody:
+ content:
+ multipart/form-data:
+ schema:
+ type:object
+ properties:
+ id:
+ # default for primitives without a special format is text/plain
+ type:string
+ format:uuid
+ profileImage:
+ # default for string with binary format is `application/octet-stream`
+ type:string
+ format:binary
+ addresses:
+ # default for arrays is based on the type in the `items`
+ # subschema, which is an object, so `application/json`
+ type:array
+ items:
+ $ref:'#/components/schemas/Address'
+
+
4.8.15.3.2 Example: Multipart Form with Encoding Objects
+
Using encoding, we can set more specific types for binary data, or non-JSON formats for complex values.
+We can also describe headers for each part:
+
requestBody:
+ content:
+ multipart/form-data:
+ schema:
+ type:object
+ properties:
+ id:
+ # default is `text/plain`
+ type:string
+ format:uuid
+ addresses:
+ # default based on the `items` subschema would be
+ # `application/json`, but we want these address objects
+ # serialized as `application/xml` instead
+ description:addressesinXMLformat
+ type:array
+ items:
+ $ref:'#/components/schemas/Address'
+ profileImage:
+ # default is application/octet-stream, but we can declare
+ # a more specific image type or types
+ type:string
+ format:binaryencoding:
- historyMetadata:
+ addresses:# require XML Content-Type in utf-8 encoding
+ # This is applied to each address part corresponding
+ # to each address in he arraycontentType:application/xml;charset=utf-8profileImage:
- # only accept png/jpeg
+ # only accept png or jpegcontentType:image/png,image/jpegheaders:X-Rate-Limit-Limit:
@@ -2212,14 +2533,27 @@
OpenAPI Specification v3.1.0
schema:
type:integer
-
4.8.16 Responses Object
+
4.8.15.3.3 Example: Multipart Form with Multiple Files
+
In accordance with [RFC7578] Section 4.3, multiple files for a single form field are uploaded using the same name (file in this example) for each file’s part:
+
requestBody:
+ content:
+ multipart/form-data:
+ schema:
+ properties:
+ # The property name 'file' will be used for all files.
+ file:
+ type:array
+ items: {}
+
A container for the expected responses of an operation.
The container maps a HTTP response code to the expected response.
The documentation is not necessarily expected to cover all possible HTTP response codes because they may not be known in advance.
However, documentation is expected to cover a successful operation response and any known errors.
-
The defaultMAY be used as a default response object for all HTTP codes
-that are not covered individually by the Responses Object.
-
The Responses ObjectMUST contain at least one response code, and if only one
+
The defaultMAY be used as a default Response Object for all HTTP codes
+that are not covered individually by the Responses Object.
+
The Responses Object MUST contain at least one response code, and if only one
response code is provided it SHOULD be the response for a successful operation
call.
Any HTTP status code can be used as the property name, but only one property per code, to describe the expected response for that HTTP status code. This field MUST be enclosed in quotation marks (for example, “200”) for compatibility between JSON and YAML. To define a range of response codes, this field MAY contain the uppercase wildcard character X. For example, 2XX represents all response codes between [200-299]. Only the following range definitions are allowed: 1XX, 2XX, 3XX, 4XX, and 5XX. If a response is defined using an explicit code, the explicit code definition takes precedence over the range definition for that code.
+
Any HTTP status code can be used as the property name, but only one property per code, to describe the expected response for that HTTP status code. This field MUST be enclosed in quotation marks (for example, “200”) for compatibility between JSON and YAML. To define a range of response codes, this field MAY contain the uppercase wildcard character X. For example, 2XX represents all response codes between 200 and 299. Only the following range definitions are allowed: 1XX, 2XX, 3XX, 4XX, and 5XX. If a response is defined using an explicit code, the explicit code definition takes precedence over the range definition for that code.
@@ -2296,7 +2630,7 @@
OpenAPI Specification v3.1.0
$ref: '#/components/schemas/ErrorModel'
4.8.17 Response Object
-
Describes a single response from an API Operation, including design-time, static
+
Describes a single response from an API operation, including design-time, static
links to operations based on the response.
4.8.17.1 Fixed Fields
@@ -2309,22 +2643,22 @@
OpenAPI Specification v3.1.0
description
+
description
string
REQUIRED. A description of the response. [CommonMark] syntax MAY be used for rich text representation.
Maps a header name to its definition. [RFC7230] Page 22 states header names are case insensitive. If a response header is defined with the name "Content-Type", it SHALL be ignored.
Maps a header name to its definition. [RFC7230] Section 3.2 states header names are case insensitive. If a response header is defined with the name "Content-Type", it SHALL be ignored.
A map containing descriptions of potential response payloads. The key is a media type or media type range, see [RFC7231] Appendix D, and the value describes it. For responses that match multiple keys, only the most specific key is applicable. e.g. text/plain overrides text/*
+
A map containing descriptions of potential response payloads. The key is a media type or media type range, see [RFC7231] Appendix D, and the value describes it. For responses that match multiple keys, only the most specific key is applicable. e.g. "text/plain" overrides "text/*"
A map of operations links that can be followed from the response. The key of the map is a short name for the link, following the naming constraints of the names for Component Objects.
A map of possible out-of band callbacks related to the parent operation.
Each value in the map is a Path Item Object that describes a set of requests that may be initiated by the API provider and the expected responses.
-The key value used to identify the path item object is an expression, evaluated at runtime, that identifies a URL to use for the callback operation.
-
To describe incoming requests from the API provider independent from another API call, use the webhooks field.
+The key value used to identify the Path Item Object is an expression, evaluated at runtime, that identifies a URL to use for the callback operation.
+
To describe incoming requests from the API provider independent from another API call, use the webhooks field.
201 Created
+Location: https://example.org/subscription/1
+
The following examples show how the various expressions evaluate, assuming the callback operation has a path parameter named eventType and a query parameter named queryUrl.
The following example uses the user provided queryUrl query string parameter to define the callback URL. This is an example of how to use a callback object to describe a WebHook callback that goes with the subscription operation to enable registering for the WebHook.
+
The following example uses the user provided queryUrl query string parameter to define the callback URL. This is similar to a webhook, but differs in that the callback only occurs because of the initial request that sent the queryUrl.
An object grouping an internal or external example value with basic summary and description metadata.
+This object is typically used in fields named examples (plural), and is a referenceable alternative to older example (singular) fields that do not support referencing or metadata.
+
Examples allow demonstration of the usage of properties, parameters and objects within OpenAPI.
4.8.19.1 Fixed Fields
@@ -2564,32 +2901,45 @@
OpenAPI Specification v3.1.0
summary
+
summary
string
Short description for the example.
-
description
+
description
string
Long description for the example. [CommonMark] syntax MAY be used for rich text representation.
-
value
+
value
Any
Embedded literal example. The value field and externalValue field are mutually exclusive. To represent examples of media types that cannot naturally represented in JSON or YAML, use a string value to contain the example, escaping where necessary.
-
externalValue
+
externalValue
string
-
A URI that points to the literal example. This provides the capability to reference examples that cannot easily be included in JSON or YAML documents. The value field and externalValue field are mutually exclusive. See the rules for resolving Relative References.
+
A URI that identifies the literal example. This provides the capability to reference examples that cannot easily be included in JSON or YAML documents. The value field and externalValue field are mutually exclusive. See the rules for resolving Relative References.
In all cases, the example value is expected to be compatible with the type schema
-of its associated value. Tooling implementations MAY choose to
-validate compatibility automatically, and reject the example value(s) if incompatible.
-
4.8.19.2 Example Object Examples
+
In all cases, the example value SHOULD be compatible with the schema of its associated value.
+Tooling implementations MAY choose to validate compatibility automatically, and reject the example value(s) if incompatible.
+
4.8.19.2 Working with Examples
+
Example Objects can be used in both Parameter Objects and Media Type Objects.
+In both Objects, this is done through the examples (plural) field.
+However, there are several other ways to provide examples: The example (singular) field that is mutually exclusive with examples in both Objects, and two keywords (the deprecated singular example and the current plural examples, which takes an array of examples) in the Schema Object that appears in the schema field of both Objects.
+Each of these fields has slightly different considerations.
+
The Schema Object’s fields are used to show example values without regard to how they might be formatted as parameters or within media type representations.
+The examples array is part of JSON Schema and is the preferred way to include examples in the Schema Object, while example is retained purely for compatibility with older versions of the OpenAPI Specification.
+
The mutually exclusive fields in the Parameter or Media Type Objects are used to show example values which SHOULD both match the schema and be formatted as they would appear as a serialized parameter or within a media type representation.
+The exact serialization and encoding is determined by various fields in the Parameter Object, or in the Media Type Object’s Encoding Object.
+Because examples using these fields represent the final serialized form of the data, they SHALLoverride any example in the corresponding Schema Object.
+
The singular example field in the Parameter or Media Type Object is concise and convenient for simple examples, but does not offer any other advantages over using Example Objects under examples.
+
Some examples cannot be represented directly in JSON or YAML.
+For all three ways of providing examples, these can be shown as string values with any escaping necessary to make the string valid in the JSON or YAML format of documents that comprise the OpenAPI Description.
+With the Example Object, such values can alternatively be handled through the externalValue field.
First, a request or response body that is just a JSON string (not an object containing a string):
+
"application/json":{
+ "schema":{
+ "type":"string"
+ },
+ "examples":{
+ "jsonBody":{
+ "description":"A body of just the JSON string \"json\"",
+ "value":"json"
+ }
+ }
+}
+
+
application/json:
+ schema:
+ type:string
+ examples:
+ jsonBody:
+ description:'A body of just the JSON string "json"'
+ value:json
+
+
In the above example, we can just show the JSON string (or any JSON value) as-is, rather than stuffing a serialized JSON value into a JSON string, which would have looked like "\"json\"".
+
In contrast, a JSON string encoded inside of a URL-style form body:
In this example, the JSON string had to be serialized before encoding it into the URL form value, so the example includes the quotation marks that are part of the JSON serialization, which are then URL percent-encoded.
4.8.20 Link Object
-
The Link object represents a possible design-time link for a response.
+
The Link Object represents a possible design-time link for a response.
The presence of a link does not guarantee the caller’s ability to successfully invoke it, rather it provides a known relationship and traversal mechanism between responses and other operations.
Unlike dynamic links (i.e. links provided in the response payload), the OAS linking mechanism does not require link information in the runtime response.
-
For computing links, and providing instructions to execute them, a runtime expression is used for accessing values in an operation and using them as parameters while invoking the linked operation.
+
For computing links and providing instructions to execute them, a runtime expression is used for accessing values in an operation and using them as parameters while invoking the linked operation.
4.8.20.1 Fixed Fields
@@ -2653,32 +3066,32 @@
OpenAPI Specification v3.1.0
operationRef
+
operationRef
string
-
A relative or absolute URI reference to an OAS operation. This field is mutually exclusive of the operationId field, and MUST point to an Operation Object. Relative operationRef values MAY be used to locate an existing Operation Object in the OpenAPI definition. See the rules for resolving Relative References.
+
A URI reference to an OAS operation. This field is mutually exclusive of the operationId field, and MUST point to an Operation Object. Relative operationRef values MAY be used to locate an existing Operation Object in the OpenAPI Description.
-
operationId
+
operationId
string
-
The name of an existing, resolvable OAS operation, as defined with a unique operationId. This field is mutually exclusive of the operationRef field.
+
The name of an existing, resolvable OAS operation, as defined with a unique operationId. This field is mutually exclusive of the operationRef field.
A map representing parameters to pass to an operation as specified with operationId or identified via operationRef. The key is the parameter name to be used, whereas the value can be a constant or an expression to be evaluated and passed to the linked operation. The parameter name can be qualified using the parameter location[{in}.]{name} for operations that use the same parameter name in different locations (e.g. path.id).
+
A map representing parameters to pass to an operation as specified with operationId or identified via operationRef. The key is the parameter name to be used (optionally qualified with the parameter location, e.g. path.id for an id parameter in the path), whereas the value can be a constant or an expression to be evaluated and passed to the linked operation.
A linked operation MUST be identified using either an operationRef or operationId.
-In the case of an operationId, it MUST be unique and resolved in the scope of the OAS document.
-Because of the potential for name clashes, the operationRef syntax is preferred
-for OpenAPI documents with external references.
+The identified or reference operation MUST be unique, and in the case of an operationId, it MUST be resolved within the scope of the OpenAPI Description (OAD).
+Because of the potential for name clashes, the operationRef syntax is preferred for multi-document OADs.
+However, because use of an operation depends on its URL path template in the Paths Object, operations from any Path Item Object that is referenced multiple times within the OAD cannot be resolved unambiguously.
+In such ambiguous cases, the resulting behavior is implementation-defined and MAY result in an error.
+
Note that it is not possible to provide a constant value to parameters that matches the syntax of a runtime expression.
+It is possible to have ambiguous parameter names, e.g. name: "id", in: "path" and name: "path.id", in: "query"; this is NOT RECOMMENDED and the behavior is implementation-defined, however implementations SHOULD prefer the qualified interpretation (path.id as a path parameter), as the names can always be qualified to disambiguate them (e.g. using query.path.id for the query parameter).
4.8.20.2 Examples
Computing a link from a request operation where the $request.path.id is used to pass a request parameter to the linked operation.
operationId: getUserAddressparameters:# get the `id` field from the request path parameter named `id`
- userId:$request.path.id
+ userid:$request.path.id# the path item of the linked operation/users/{userid}/address:parameters:
- -name:userid
- in:path
- required:true
- description:theuseridentifier,asuserId
- schema:
- type:string
+ -name:userid
+ in:path
+ required:true
+ description:theuseridentifier,asuserId
+ schema:
+ type:string# linked operationget:operationId:getUserAddress
@@ -2745,48 +3161,48 @@
OpenAPI Specification v3.1.0
userUuid: $response.body#/uuid
Clients follow all links at their discretion.
-Neither permissions, nor the capability to make a successful call to that link, is guaranteed
+Neither permissions nor the capability to make a successful call to that link is guaranteed
solely by the existence of a relationship.
-
4.8.20.3 OperationRef Examples
+
4.8.20.3 operationRef Examples
As references to operationIdMAY NOT be possible (the operationId is an optional
field in an Operation Object), references MAY also be made through a relative operationRef:
links:UserRepositories:# returns array of '#/components/schemas/repository'
- operationRef:'#/paths/~12.0~1repositories~1{username}/get'
+ operationRef:'#/paths/~12.0~1repositories~1%7Busername%7D/get'parameters:username:$response.body#/username
-
or an absolute operationRef:
+
or a URI operationRef:
links:UserRepositories:# returns array of '#/components/schemas/repository'
- operationRef:'https://na2.gigantic-server.com/#/paths/~12.0~1repositories~1{username}/get'
+ operationRef:https://na2.gigantic-server.com/#/paths/~12.0~1repositories~1%7Busername%7D/getparameters:username:$response.body#/username
-
Note that in the use of operationRef, the escaped forward-slash is necessary when
-using JSON references.
+
Note that in the use of operationRef the escaped forward-slash is necessary when
+using JSON Pointer, and it is necessary to URL-encode { and } as %7B and %7D, respectively, when using JSON Pointer as URI fragments.
4.8.20.4 Runtime Expressions
Runtime expressions allow defining values based on information that will only be available within the HTTP message in an actual API call.
This mechanism is used by Link Objects and Callback Objects.
The runtime expression is defined by the following [ABNF] syntax
The Header Object follows the structure of the Parameter Object, including determining its serialization strategy based on whether schema or content is present, with the following changes:
nameMUST NOT be specified, it is given in the corresponding headers map.
inMUST NOT be specified, it is implicitly in header.
-
All traits that are affected by the location MUST be applicable to a location of header (for example, style).
+
All traits that are affected by the location MUST be applicable to a location of header (for example, style). This means that allowEmptyValue and allowReservedMUST NOT be used, and style, if used, MUST be limited to "simple".
-
4.8.21.1 Header Object Example
+
4.8.21.1 Fixed Fields
+
4.8.21.1.1 Common Fixed Fields
+
These fields MAY be used with either content or schema.
+
+
+
+
Field Name
+
Type
+
Description
+
+
+
+
+
description
+
string
+
A brief description of the header. This could contain examples of use. [CommonMark] syntax MAY be used for rich text representation.
+
+
+
required
+
boolean
+
Determines whether this header is mandatory. The default value is false.
+
+
+
deprecated
+
boolean
+
Specifies that the header is deprecated and SHOULD be transitioned out of usage. Default value is false.
For simpler scenarios, a schema and style can describe the structure and syntax of the header.
+When example or examples are provided in conjunction with the schema field, the example MUST follow the prescribed serialization strategy for the header.
+
Serializing with schema is NOT RECOMMENDED for headers with parameters (name=value pairs following a ;) in their values, or where values might have non-URL-safe characters; see Appendix D for details.
+
When example or examples are provided in conjunction with the schema field, the example SHOULD match the specified schema and follow the prescribed serialization strategy for the header.
+The example and examples fields are mutually exclusive, and if either is present it SHALLoverride any example in the schema.
+
+
+
+
Field Name
+
Type
+
Description
+
+
+
+
+
style
+
string
+
Describes how the header value will be serialized. The default (and only legal value for headers) is "simple".
+
+
+
explode
+
boolean
+
When this is true, header values of type array or object generate a single header whose value is a comma-separated list of the array items or key-value pairs of the map, see Style Examples. For other data types this field has no effect. The default value is false.
For more complex scenarios, the content field can define the media type and schema of the header, as well as give examples of its use.
+Using content with a text/plain media type is RECOMMENDED for headers where the schema strategy is not appropriate.
Requiring that a strong ETag header (with a value starting with " rather than W/) is present. Note the use of content, because using schema and style would require the " to be percent-encoded as %22:
Adds metadata to a single tag that is used by the Operation Object.
It is not mandatory to have a Tag Object per tag defined in the Operation Object instances.
-
4.8.22.1 Fixed Fields
+
4.8.22.1 Fixed Fields
@@ -2874,17 +3405,17 @@
OpenAPI Specification v3.1.0
name
+
name
string
REQUIRED. The name of the tag.
-
description
+
description
string
A description for the tag. [CommonMark] syntax MAY be used for rich text representation.
REQUIRED. The reference identifier. This MUST be in the form of a URI.
-
summary
+
summary
string
A short summary which by default SHOULD override that of the referenced component. If the referenced object-type does not allow a summary field, then this field has no effect.
-
description
+
description
string
A description which by default SHOULD override that of the referenced component. [CommonMark] syntax MAY be used for rich text representation. If the referenced object-type does not allow a description field, then this field has no effect.
-
This object cannot be extended with additional properties and any properties added SHALL be ignored.
-
Note that this restriction on additional properties is a difference between Reference Objects and Schema Objects that contain a $ref keyword.
+
This object cannot be extended with additional properties, and any properties added SHALL be ignored.
+
Note that this restriction on additional properties is a difference between Reference Objects and Schema Objects that contain a $ref keyword.
The Schema Object allows the definition of input and output data types.
-These types can be objects, but also primitives and arrays. This object is a superset of the JSON Schema Specification Draft 2020-12.
Unless stated otherwise, the property definitions follow those of JSON Schema and do not add any additional semantics.
+These types can be objects, but also primitives and arrays. This object is a superset of the JSON Schema Specification Draft 2020-12. The empty schema (which allows any instance to validate) MAY be represented by the boolean value true and a schema which allows no instance to validate MAY be represented by the boolean value false.
Unless stated otherwise, the keyword definitions follow those of JSON Schema and do not add any additional semantics; this includes keywords such as $schema, $id, $ref, and $dynamicRef being URIs rather than URLs.
Where JSON Schema indicates that behavior is defined by the application (e.g. for annotations), OAS also defers the definition of semantics to the application consuming the OpenAPI document.
The OpenAPI Schema Object dialect for this version of the specification is identified by the URI https://spec.openapis.org/oas/3.1/dialect/base (the “OAS dialect schema id”).
-
The following properties are taken from the JSON Schema specification but their definitions have been extended by the OAS:
The OpenAPI Schema Object dialect for this version of the specification is identified by the URI https://spec.openapis.org/oas/3.1/dialect/base (the “OAS dialect schema id”).
+
The following keywords are taken from the JSON Schema specification but their definitions have been extended by the OAS:
description - [CommonMark] syntax MAY be used for rich text representation.
-
format - See Data Type Formats for further details. While relying on JSON Schema’s defined formats, the OAS offers a few additional predefined formats.
+
format - See Data Type Formats for further details. While relying on JSON Schema’s defined formats, the OAS offers a few additional predefined formats.
-
In addition to the JSON Schema properties comprising the OAS dialect, the Schema Object supports keywords from any other vocabularies, or entirely arbitrary properties.
-
The OpenAPI Specification’s base vocabulary is comprised of the following keywords:
-
4.8.24.2 Fixed Fields
+
In addition to the JSON Schema keywords comprising the OAS dialect, the Schema Object supports keywords from any other vocabularies, or entirely arbitrary properties.
+
JSON Schema implementations MAY choose to treat keywords defined by the OpenAPI Specification’s base vocabulary as unknown keywords, due to its inclusion in the OAS dialect with a $vocabulary value of false.
+The OAS base vocabulary is comprised of the following keywords:
Adds support for polymorphism. The discriminator is an object name that is used to differentiate between other schemas which may satisfy the payload description. See Composition and Inheritance for more details.
+
Adds support for polymorphism. The discriminator is used to determine which of a set of schemas a payload is expected to satisfy. See Composition and Inheritance for more details.
This MAY be used only on properties schemas. It has no effect on root schemas. Adds additional metadata to describe the XML representation of this property.
+
This MAY be used only on property schemas. It has no effect on root schemas. Adds additional metadata to describe the XML representation of this property.
Additional external documentation for this schema.
-
example
+
example
Any
-
A free-form property to include an example of an instance for this schema. To represent examples that cannot be naturally represented in JSON or YAML, a string value can be used to contain the example with escaping where necessary.
Deprecated: The example property has been deprecated in favor of the JSON Schema examples keyword. Use of example is discouraged, and later versions of this specification may remove it.
+
A free-form field to include an example of an instance for this schema. To represent examples that cannot be naturally represented in JSON or YAML, a string value can be used to contain the example with escaping where necessary.
Deprecated: The example field has been deprecated in favor of the JSON Schema examples keyword. Use of example is discouraged, and later versions of this specification may remove it.
This object MAY be extended with Specification Extensions, though as noted, additional properties MAY omit the x- prefix within this object.
-
4.8.24.2.1 Composition and Inheritance (Polymorphism)
-
The OpenAPI Specification allows combining and extending model definitions using the allOf property of JSON Schema, in effect offering model composition.
+
4.8.24.3 Extended Validation with Annotations
+
JSON Schema Draft 2020-12 supports collecting annotations, including treating unrecognized keywords as annotations.
+OAS implementations MAY use such annotations, including extensions not recognized as part of a declared JSON Schema vocabulary, as the basis for further validation.
+Note that JSON Schema Draft 2020-12 does not require an x- prefix for extensions.
The readOnly and writeOnly keywords are annotations, as JSON Schema is not aware of how the data it is validating is being used.
+Validation of these keywords MAY be done by checking the annotation, the read or write direction, and (if relevant) the current value of the field.
+JSON Schema Validation Draft 2020-12 §9.4 defines the expectations of these keywords, including that a resource (described as the “owning authority”) MAY either ignore a readOnly field or treat it as an error.
+
Fields that are both required and read-only are an example of when it is beneficial to ignore a readOnly: true constraint in a PUT, particularly if the value has not been changed.
+This allows correctly requiring the field on a GET and still using the same representation and schema with PUT.
+Even when read-only fields are not required, stripping them is burdensome for clients, particularly when the JSON data is complex or deeply nested.
+
Note that the behavior of readOnly in particular differs from that specified by version 3.0 of this specification.
+
4.8.24.4 Data Modeling Techniques
+
4.8.24.4.1 Composition and Inheritance (Polymorphism)
+
The OpenAPI Specification allows combining and extending model definitions using the allOf keyword of JSON Schema, in effect offering model composition.
allOf takes an array of object definitions that are validated independently but together compose a single object.
While composition offers model extensibility, it does not imply a hierarchy between the models.
-To support polymorphism, the OpenAPI Specification adds the discriminator field.
-When used, the discriminator will be the name of the property that decides which schema definition validates the structure of the model.
+To support polymorphism, the OpenAPI Specification adds the discriminator field.
+When used, the discriminator indicates the name of the property that hints which schema definition is expected to validate the structure of the model.
As such, the discriminator field MUST be a required field.
There are two ways to define the value of a discriminator for an inheriting instance.
Use the schema name.
-
Override the schema name by overriding the property with a new value. If a new value exists, this takes precedence over the schema name.
-As such, inline schema definitions, which do not have a given id, cannot be used in polymorphism.
+
Override the schema name by overriding the property with a new value. If a new value exists, this takes precedence over the schema name.
+
+
4.8.24.4.2 Generic (Template) Data Structures
+
Implementations MAY support defining generic or template data structures using JSON Schema’s dynamic referencing feature:
+
+
$dynamicAnchor identifies a set of possible schemas (including a default placeholder schema) to which a $dynamicRef can resolve
+
$dynamicRef resolves to the first matching $dynamicAnchor encountered on its path from the schema entry point to the reference, as described in the JSON Schema specification
-
4.8.24.2.2 XML Modeling
-
The xml property allows extra definitions when translating the JSON definition to XML.
+
An example is included in the “Schema Object Examples” section below, and further information can be found on the Learn OpenAPI site’s “Dynamic References” page.
+
4.8.24.4.3 Annotated Enumerations
+
The Schema Object’s enum keyword does not allow associating descriptions or other information with individual values.
+
Implementations MAY support recognizing a oneOf or anyOf where each subschema in the keyword’s array consists of a const keyword and annotations such as title or description as an enumerated type with additional information. The exact behavior of this pattern beyond what is required by JSON Schema is implementation-defined.
+
4.8.24.4.4 XML Modeling
+
The xml field allows extra definitions when translating the JSON definition to XML.
The XML Object contains additional information about the available options.
-
4.8.24.2.3 Specifying Schema Dialects
+
4.8.24.5 Specifying Schema Dialects
It is important for tooling to be able to determine which dialect or meta-schema any given resource wishes to be processed with: JSON Schema Core, JSON Schema Validation, OpenAPI Schema dialect, or some custom meta-schema.
-
The $schema keyword MAY be present in any root Schema Object, and if present MUST be used to determine which dialect should be used when processing the schema. This allows use of Schema Objects which comply with other drafts of JSON Schema than the default Draft 2020-12 support. Tooling MUST support the OAS dialect schema id, and MAY support additional values of $schema.
-
To allow use of a different default $schema value for all Schema Objects contained within an OAS document, a jsonSchemaDialect value may be set within the OpenAPI Object. If this default is not set, then the OAS dialect schema id MUST be used for these Schema Objects. The value of $schema within a Schema Object always overrides any default.
-
When a Schema Object is referenced from an external resource which is not an OAS document (e.g. a bare JSON Schema resource), then the value of the $schema keyword for schemas within that resource MUST follow JSON Schema rules.
-
4.8.24.3 Schema Object Examples
-
4.8.24.3.1 Primitive Sample
+
The $schema keyword MAY be present in any Schema Object that is a schema resource root, and if present MUST be used to determine which dialect should be used when processing the schema. This allows use of Schema Objects which comply with other drafts of JSON Schema than the default Draft 2020-12 support. Tooling MUST support the OAS dialect schema id, and MAY support additional values of $schema.
+
To allow use of a different default $schema value for all Schema Objects contained within an OAS document, a jsonSchemaDialect value may be set within the OpenAPI Object. If this default is not set, then the OAS dialect schema id MUST be used for these Schema Objects. The value of $schema within a resource root Schema Object always overrides any default.
+
For standalone JSON Schema documents that do not set $schema, or for Schema Objects in OpenAPI description documents that are notcomplete documents, the dialect SHOULD be assumed to be the OAS dialect.
+However, for maximum interoperability, it is RECOMMENDED that OpenAPI description authors explicitly set the dialect through $schema in such documents.
"type":"string"}},
- "required":[
- "name",
- "petType"
- ]
+ "required":["name","petType"]},"Cat":{
- "description":"A representation of a cat. Note that `Cat` will be used as the discriminator value.",
+ "description":"A representation of a cat. Note that `Cat` will be used as the discriminating value.","allOf":[{"$ref":"#/components/schemas/Pet"
@@ -3229,22 +3801,15 @@
OpenAPI Specification v3.1.0
"type":"string","description":"The measured skill for hunting","default":"lazy",
- "enum":[
- "clueless",
- "lazy",
- "adventurous",
- "aggressive"
- ]
+ "enum":["clueless","lazy","adventurous","aggressive"]}},
- "required":[
- "huntingSkill"
- ]
+ "required":["huntingSkill"]}]},"Dog":{
- "description":"A representation of a dog. Note that `Dog` will be used as the discriminator value.",
+ "description":"A representation of a dog. Note that `Dog` will be used as the discriminating value.","allOf":[{"$ref":"#/components/schemas/Pet"
@@ -3260,9 +3825,7 @@
When request bodies or response payloads may be one of a number of different schemas, a discriminator object can be used to aid in serialization, deserialization, and validation. The discriminator is a specific object in a schema which is used to inform the consumer of the document of an alternative schema based on the value associated with it.
-
When using the discriminator, inline schemas will not be considered.
-
4.8.25.1 Fixed Fields
+
When request bodies or response payloads may be one of a number of different schemas, a Discriminator Object gives a hint about the expected schema of the document.
+This hint can be used to aid in serialization, deserialization, and validation.
+The Discriminator Object does this by implicitly or explicitly associating the possible values of a named property with alternative schemas.
+
Note that discriminatorMUST NOT change the validation outcome of the schema.
+
4.8.25.1 Fixed Fields
@@ -3329,65 +4002,80 @@
OpenAPI Specification v3.1.0
propertyName
+
propertyName
string
-
REQUIRED. The name of the property in the payload that will hold the discriminator value.
+
REQUIRED. The name of the property in the payload that will hold the discriminating value. This property SHOULD be required in the payload schema, as the behavior when the property is absent is undefined.
-
mapping
+
mapping
Map[string, string]
-
An object to hold mappings between payload values and schema names or references.
+
An object to hold mappings between payload values and schema names or URI references.
The discriminator object is legal only when using one of the composite keywords oneOf, anyOf, allOf.
-
In OAS 3.0, a response payload MAY be described to be exactly one of any number of types:
+
4.8.25.2 Conditions for Using the Discriminator Object
+
The Discriminator Object is legal only when using one of the composite keywords oneOf, anyOf, allOf.
+
In both the oneOf and anyOf use cases, where those keywords are adjacent to discriminator, all possible schemas MUST be listed explicitly.
+
To avoid redundancy, the discriminator MAY be added to a parent schema definition, and all schemas building on the parent schema via an allOf construct may be used as an alternate schema.
+
The allOf form of discriminator is only useful for non-validation use cases; validation with the parent schema with this form of discriminatordoes not perform a search for child schemas or use them in validation in any way.
+This is because discriminator cannot change the validation outcome, and no standard JSON Schema keyword connects the parent schema to the child schemas.
+
The behavior of any configuration of oneOf, anyOf, allOf and discriminator that is not described above is undefined.
+
4.8.25.3 Options for Mapping Values to Schemas
+
The value of the property named in propertyName is used as the name of the associated schema under the Components Object, unless a mapping is present for that value.
+The mapping entry maps a specific property value to either a different schema component name, or to a schema identified by a URI.
+When using implicit or explicit schema component names, inline oneOf or anyOf subschemas are not considered.
+The behavior of a mapping value that is both a valid schema name and a valid relative URI reference is implementation-defined, but it is RECOMMENDED that it be treated as a schema name.
+To ensure that an ambiguous value (e.g. "foo") is treated as a relative URI reference by all implementations, authors MUST prefix it with the "." path segment (e.g. "./foo").
+
Mapping keys MUST be string values, but tooling MAY convert response values to strings for comparison.
+However, the exact nature of such conversions are implementation-defined.
which means the payload MUST, by validation, match exactly one of the schemas described by Cat, Dog, or Lizard. In this case, a discriminator MAY act as a “hint” to shortcut validation and selection of the matching schema which may be a costly operation, depending on the complexity of the schema. We can then describe exactly which field tells us which schema to use:
+
which means the payload MUST, by validation, match exactly one of the schemas described by Cat, Dog, or Lizard. Deserialization of a oneOf can be a costly operation, as it requires determining which schema matches the payload and thus should be used in deserialization. This problem also exists for anyOf schemas. A discriminatorMAY be used as a “hint” to improve the efficiency of selection of the matching schema. The discriminator field cannot change the validation result of the oneOf, it can only help make the deserialization more efficient and provide better error messaging. We can specify the exact field that tells us which schema is expected to match the instance:
The expectation now is that a property with name petTypeMUST be present in the response payload, and the value will correspond to the name of a schema defined in the OAS document. Thus the response payload:
+
The expectation now is that a property with name petTypeMUST be present in the response payload, and the value will correspond to the name of a schema defined in the OpenAPI Description. Thus the response payload:
{"id":12345,"petType":"Cat"}
-
Will indicate that the Cat schema be used in conjunction with this payload.
-
In scenarios where the value of the discriminator field does not match the schema name or implicit mapping is not possible, an optional mapping definition MAY be used:
+
will indicate that the Cat schema is expected to match this payload.
+
In scenarios where the value of the discriminator field does not match the schema name or implicit mapping is not possible, an optional mapping definition MAY be used:
Here the discriminator value of dog will map to the schema #/components/schemas/Dog, rather than the default (implicit) value of Dog. If the discriminator value does not match an implicit or explicit mapping, no schema can be determined and validation SHOULD fail. Mapping keys MUST be string values, but tooling MAY convert response values to strings for comparison.
-
When used in conjunction with the anyOf construct, the use of the discriminator can avoid ambiguity where multiple schemas may satisfy a single payload.
-
In both the oneOf and anyOf use cases, all possible schemas MUST be listed explicitly. To avoid redundancy, the discriminator MAY be added to a parent schema definition, and all schemas comprising the parent schema in an allOf construct may be used as an alternate schema.
-
For example:
+
Here the discriminating value of dog will map to the schema #/components/schemas/Dog, rather than the default (implicit) value of #/components/schemas/dog. If the discriminating value does not match an implicit or explicit mapping, no schema can be determined and validation SHOULD fail.
+
When used in conjunction with the anyOf construct, the use of the discriminator can avoid ambiguity for serializers/deserializers where multiple schemas may satisfy a single payload.
+
This example shows the allOf usage, which avoids needing to reference all child schemas in the parent:
dog: DogCat:allOf:
- -$ref:'#/components/schemas/Pet'
- -type:object
- # all other properties specific to a `Cat`
- properties:
- name:
- type:string
+ -$ref:'#/components/schemas/Pet'
+ -type:object
+ # all other properties specific to a `Cat`
+ properties:
+ name:
+ type:stringDog:allOf:
- -$ref:'#/components/schemas/Pet'
- -type:object
- # all other properties specific to a `Dog`
- properties:
- bark:
- type:string
+ -$ref:'#/components/schemas/Pet'
+ -type:object
+ # all other properties specific to a `Dog`
+ properties:
+ bark:
+ type:stringLizard:allOf:
- -$ref:'#/components/schemas/Pet'
- -type:object
- # all other properties specific to a `Lizard`
- properties:
- lovesRocks:
- type:boolean
-
-
a payload like this:
+ -$ref:'#/components/schemas/Pet'
+ -type:object
+ # all other properties specific to a `Lizard`
+ properties:
+ lovesRocks:
+ type:boolean
+
+
Validated against the Pet schema, a payload like this:
will indicate that the Cat schema be used. Likewise this schema:
+
will indicate that the #/components/schemas/Cat schema is expected to match. Likewise this payload:
{"petType":"dog","bark":"soft"}
-
will map to Dog because of the definition in the mapping element.
+
will map to #/components/schemas/Dog because the dog entry in the mapping element maps to Dog which is the schema name for #/components/schemas/Dog.
4.8.26 XML Object
A metadata object that allows for more fine-tuned XML model definitions.
-
When using arrays, XML element names are not inferred (for singular/plural forms) and the name property SHOULD be used to add that information.
+
When using arrays, XML element names are not inferred (for singular/plural forms) and the name field SHOULD be used to add that information.
See examples for expected behavior.
-
4.8.26.1 Fixed Fields
+
4.8.26.1 Fixed Fields
@@ -3448,41 +4136,48 @@
OpenAPI Specification v3.1.0
name
+
name
string
-
Replaces the name of the element/attribute used for the described schema property. When defined within items, it will affect the name of the individual XML elements within the list. When defined alongside type being array (outside the items), it will affect the wrapping element and only if wrapped is true. If wrapped is false, it will be ignored.
+
Replaces the name of the element/attribute used for the described schema property. When defined within items, it will affect the name of the individual XML elements within the list. When defined alongside type being "array" (outside the items), it will affect the wrapping element if and only if wrapped is true. If wrapped is false, it will be ignored.
-
namespace
+
namespace
string
-
The URI of the namespace definition. This MUST be in the form of an absolute URI.
+
The URI of the namespace definition. Value MUST be in the form of a non-relative URI.
Declares whether the property definition translates to an attribute instead of an element. Default value is false.
-
wrapped
+
wrapped
boolean
-
MAY be used only for an array definition. Signifies whether the array is wrapped (for example, <books><book/><book/></books>) or unwrapped (<book/><book/>). Default value is false. The definition takes effect only when defined alongside type being array (outside the items).
+
MAY be used only for an array definition. Signifies whether the array is wrapped (for example, <books><book/><book/></books>) or unwrapped (<book/><book/>). Default value is false. The definition takes effect only when defined alongside type being "array" (outside the items).
The namespace field is intended to match the syntax of XML namespaces, although there are a few caveats:
+
+
Versions 3.1.0, 3.0.3, and earlier of this specification erroneously used the term “absolute URI” instead of “non-relative URI”, so authors using namespaces that include a fragment should check tooling support carefully.
+
XML allows but discourages relative URI-references, while this specification outright forbids them.
+
XML 1.1 allows IRIs ([RFC3987]) as namespaces, and specifies that namespaces are compared without any encoding or decoding, which means that IRIs encoded to meet this specification’s URI syntax requirement cannot be compared to IRIs as-is.
+
4.8.26.2 XML Object Examples
-
The examples of the XML object definitions are included inside a property definition of a Schema Object with a sample of the XML representation of it.
+
Each of the following examples represent the value of the properties keyword in a Schema Object that is omitted for brevity.
+The JSON and YAML representations of the properties value are followed by an example XML representation produced for the single property shown.
Defines a security scheme that can be used by the operations.
-
Supported schemes are HTTP authentication, an API key (either as a header, a cookie parameter or as a query parameter), mutual TLS (use of a client certificate), OAuth2’s common flows (implicit, password, client credentials and authorization code) as defined in [RFC6749], and OpenID Connect Discovery.
-Please note that as of 2020, the implicit flow is about to be deprecated by OAuth 2.0 Security Best Current Practice. Recommended for most use case is Authorization Code Grant flow with PKCE.
-
4.8.27.1 Fixed Fields
+
Supported schemes are HTTP authentication, an API key (either as a header, a cookie parameter or as a query parameter), mutual TLS (use of a client certificate), OAuth2’s common flows (implicit, password, client credentials and authorization code) as defined in [RFC6749], and [OpenID-Connect-Core].
+Please note that as of 2020, the implicit flow is about to be deprecated by OAuth 2.0 Security Best Current Practice. Recommended for most use cases is Authorization Code Grant flow with PKCE.
+
4.8.27.1 Fixed Fields
@@ -3750,58 +4445,58 @@
OpenAPI Specification v3.1.0
type
+
type
string
Any
REQUIRED. The type of the security scheme. Valid values are "apiKey", "http", "mutualTLS", "oauth2", "openIdConnect".
-
description
+
description
string
Any
A description for security scheme. [CommonMark] syntax MAY be used for rich text representation.
-
name
+
name
string
apiKey
REQUIRED. The name of the header, query or cookie parameter to be used.
-
in
+
in
string
apiKey
-
REQUIRED. The location of the API key. Valid values are "query", "header" or "cookie".
+
REQUIRED. The location of the API key. Valid values are "query", "header", or "cookie".
A hint to the client to identify how the bearer token is formatted. Bearer tokens are usually generated by an authorization server, so this information is primarily for documentation purposes.
+
A hint to the client to identify how the bearer token is formatted. Bearer tokens are usually generated by an authorization server, so this information is primarily for documentation purposes.
REQUIRED. An object containing configuration information for the flow types supported.
-
openIdConnectUrl
+
openIdConnectUrl
string
openIdConnect
-
REQUIRED. OpenId Connect URL to discover OAuth2 configuration values. This MUST be in the form of a URL. The OpenID Connect standard requires the use of TLS.
Lists the required security schemes to execute this operation.
-The name used for each property MUST correspond to a security scheme declared in the Security Schemes under the Components Object.
-
Security Requirement Objects that contain multiple schemes require that all schemes MUST be satisfied for a request to be authorized.
+The name used for each property MUST correspond to a security scheme declared in the Security Schemes under the Components Object.
+
A Security Requirement Object MAY refer to multiple security schemes in which case all schemes MUST be satisfied for a request to be authorized.
This enables support for scenarios where multiple query parameters or HTTP headers are required to convey security information.
-
When a list of Security Requirement Objects is defined on the OpenAPI Object or Operation Object, only one of the Security Requirement Objects in the list needs to be satisfied to authorize the request.
+
When the security field is defined on the OpenAPI Object or Operation Object and contains multiple Security Requirement Objects, only one of the entries in the list needs to be satisfied to authorize the request.
+This enables support for scenarios where the API allows multiple, independent security schemes.
+
An empty Security Requirement Object ({}) indicates anonymous access is supported.
4.8.30.1 Patterned Fields
@@ -3982,13 +4688,14 @@
OpenAPI Specification v3.1.0
{name}
+
{name}
[string]
-
Each name MUST correspond to a security scheme which is declared in the Security Schemes under the Components Object. If the security scheme is of type "oauth2" or "openIdConnect", then the value is a list of scope names required for the execution, and the list MAY be empty if authorization does not require a specified scope. For other security scheme types, the array MAY contain a list of role names which are required for the execution, but are not otherwise defined or exchanged in-band.
+
Each name MUST correspond to a security scheme which is declared in the Security Schemes under the Components Object. If the security scheme is of type "oauth2" or "openIdConnect", then the value is a list of scope names required for the execution, and the list MAY be empty if authorization does not require a specified scope. For other security scheme types, the array MAY contain a list of role names which are required for the execution, but are not otherwise defined or exchanged in-band.
While the OpenAPI Specification tries to accommodate most use cases, additional data can be added to extend the specification at certain points.
-
The extensions properties are implemented as patterned fields that are always prefixed by "x-".
+
The extensions properties are implemented as patterned fields that are always prefixed by x-.
@@ -4041,13 +4742,16 @@
OpenAPI Specification v3.1.0
^x-
+
^x-
Any
-
Allows extensions to the OpenAPI Schema. The field name MUST begin with x-, for example, x-internal-id. Field names beginning x-oai- and x-oas- are reserved for uses defined by the OpenAPI Initiative. The value can be null, a primitive, an array or an object.
+
Allows extensions to the OpenAPI Schema. The field name MUST begin with x-, for example, x-internal-id. Field names beginning x-oai- and x-oas- are reserved for uses defined by the OpenAPI Initiative. The value can be any valid JSON value (null, a primitive, an array, or an object.)
-
The extensions may or may not be supported by the available tooling, but those may be extended as well to add requested support (if tools are internal or open-sourced).
Extensions are one of the best ways to prove the viability of proposed additions to the specification.
+It is therefore RECOMMENDED that implementations be designed for extensibility to support community experimentation.
+
Support for any one extension is OPTIONAL, and support for one extension does not imply support for others.
4.10 Security Filtering
Some objects in the OpenAPI Specification MAY be declared and remain empty, or be completely removed, even though they are inherently the core of the API documentation.
The reasoning is to allow an additional layer of access control over the documentation.
@@ -4057,6 +4761,25 @@
OpenAPI Specification v3.1.0
Paths Object MAY be present but empty. It may be counterintuitive, but this may tell the viewer that they got to the right place, but can’t access any documentation. They would still have access to at least the Info Object which may contain additional information regarding authentication.
The Path Item ObjectMAY be empty. In this case, the viewer will be aware that the path exists, but will not be able to see any of its operations or parameters. This is different from hiding the path itself from the Paths Object, because the user will be aware of its existence. This allows the documentation provider to finely control what the viewer can see.
+
5. Security Considerations
+
5.1 OpenAPI Description Formats
+
OpenAPI Descriptions use a combination of JSON, YAML, and JSON Schema, and therefore share their security considerations:
In addition, OpenAPI Descriptions are processed by a wide variety of tooling for numerous different purposes, such as client code generation, documentation generation, server side routing, and API testing. OpenAPI Description authors must consider the risks of the scenarios where the OpenAPI Description may be used.
+
5.3 Security Schemes
+
An OpenAPI Description describes the security schemes used to protect the resources it defines. The security schemes available offer varying degrees of protection. Factors such as the sensitivity of the data and the potential impact of a security breach should guide the selection of security schemes for the API resources. Some security schemes, such as basic auth and OAuth Implicit flow, are supported for compatibility with existing APIs. However, their inclusion in OpenAPI does not constitute an endorsement of their use, particularly for highly sensitive data or operations.
+
5.4 Handling External Resources
+
OpenAPI Descriptions may contain references to external resources that may be dereferenced automatically by consuming tools. External resources may be hosted on different domains that may be untrusted.
+
5.5 Handling Reference Cycles
+
References in an OpenAPI Description may cause a cycle. Tooling must detect and handle cycles to prevent resource exhaustion.
+
5.6 Markdown and HTML Sanitization
+
Certain fields allow the use of Markdown which can contain HTML including script. It is the responsibility of tooling to appropriately sanitize the Markdown.
A. Appendix A: Revision History
@@ -4068,6 +4791,11 @@
OpenAPI Specification v3.1.0
OpenAPI Specification v3.1.0
OpenAPI Specification v3.1.0
B. Appendix B: Data Type Conversion
+
Serializing typed data to plain text, which can occur in text/plain message bodies or multipart parts, as well as in the application/x-www-form-urlencoded format in either URL query strings or message bodies, involves significant implementation- or application-defined behavior.
+
Schema Objects validate data based on the JSON Schema data model, which only recognizes four primitive data types: strings (which are only broadly interoperable as UTF-8), numbers, booleans, and null.
+Notably, integers are not a distinct type from other numbers, with type: "integer" being a convenience defined mathematically, rather than based on the presence or absence of a decimal point in any string representation.
+
The Parameter Object, Header Object, and Encoding Object offer features to control how to arrange values from array or object types.
+They can also be used to control how strings are further encoded to avoid reserved or illegal characters.
+However, there is no general-purpose specification for converting schema-validated non-UTF-8 primitive data types (or entire arrays or objects) to strings.
+
Two cases do offer standards-based guidance:
+
+
[RFC3987] Section 3.1 provides guidance for converting non-Unicode strings to UTF-8, particularly in the context of URIs (and by extension, the form media types which use the same encoding rules)
+
[RFC6570] Section 2.3 specifies which values, including but not limited to null, are considered undefined and therefore treated specially in the expansion process when serializing based on that specification
+
+
Implementations of RFC6570 often have their own conventions for converting non-string values, but these are implementation-specific and not defined by the RFC itself.
+This is one reason for the OpenAPI Specification to leave these conversions as implementation-defined: It allows using RFC6570 implementations regardless of how they choose to perform the conversions.
+
To control the serialization of numbers, booleans, and null (or other values RFC6570 deems to be undefined) more precisely, schemas can be defined as type: "string" and constrained using pattern, enum, format, and other keywords to communicate how applications must pre-convert their data prior to schema validation.
+The resulting strings would not require any further type conversion.
+
The format keyword can assist in serialization.
+Some formats (such as date-time) are unambiguous, while others (such as decimal in the Format Registry) are less clear.
+However, care must be taken with format to ensure that the specific formats are supported by all relevant tools as unrecognized formats are ignored.
+
Requiring input as pre-formatted, schema-validated strings also improves round-trip interoperability as not all programming languages and environments support the same data types.
+
C. Appendix C: Using RFC6570-Based Serialization
+
Serialization is defined in terms of [RFC6570] URI Templates in three scenarios:
When encoding for application/x-www-form-urlencoded and any of style, explode, or allowReserved are used
+
+
+
+
Implementations of this specification MAY use an implementation of RFC6570 to perform variable expansion, however, some caveats apply.
+
Note that when using style: "form" RFC6570 expansion to produce an application/x-www-form-urlencoded HTTP message body, it is necessary to remove the ? prefix that is produced to satisfy the URI query string syntax.
+
When using style and similar keywords to produce a multipart/form-data body, the query string names are placed in the name parameter of the Content-Disposition part header, and the values are placed in the corresponding part body; the ?, =, and & characters are not used.
+Note that while [RFC7578] allows using [RFC3986] percent-encoding in “file names”, it does not otherwise address the use of percent-encoding within the format.
+RFC7578 discusses character set and encoding issues for multipart/form-data in detail, and it is RECOMMENDED that OpenAPI Description authors read this guidance carefully before deciding to use RFC6570-based serialization with this media type.
+
Note also that not all RFC6570 implementations support all four levels of operators, all of which are needed to fully support the OpenAPI Specification’s usage.
+Using an implementation with a lower level of support will require additional manual construction of URI Templates to work around the limitations.
+
C.1 Equivalences Between Fields and RFC6570 Operators
+
Certain field values translate to RFC6570 operators (or lack thereof):
+
+
+
+
field
+
value
+
equivalent
+
+
+
+
+
style
+
"simple"
+
n/a
+
+
+
style
+
"matrix"
+
; prefix operator
+
+
+
style
+
"label"
+
. prefix operator
+
+
+
style
+
"form"
+
? prefix operator
+
+
+
allowReserved
+
false
+
n/a
+
+
+
allowReserved
+
true
+
+ prefix operator
+
+
+
explode
+
false
+
n/a
+
+
+
explode
+
true
+
* modifier suffix
+
+
+
+
Multiple style: "form" parameters are equivalent to a single RFC6570 variable list using the ? prefix operator:
This example is equivalent to RFC6570’s {?foo*,bar}, and NOT{?foo*}{&bar}. The latter is problematic because if foo is not defined, the result will be an invalid URI.
+The & prefix operator has no equivalent in the Parameter Object.
+
Note that RFC6570 does not specify behavior for compound values beyond the single level addressed by explode. The result of using objects or arrays where no behavior is clearly specified for them is implementation-defined.
+
C.2 Delimiters in Parameter Values
+
Delimiters used by RFC6570 expansion, such as the , used to join arrays or object values with style: "simple", are all automatically percent-encoded as long as allowReserved is false.
+Note that since RFC6570 does not define a way to parse variables based on a URI Template, users must take care to first split values by delimiter before percent-decoding values that might contain the delimiter character.
+
When allowReserved is true, both percent-encoding (prior to joining values with a delimiter) and percent-decoding (after splitting on the delimiter) must be done manually at the correct time.
+
See Appendix E for additional guidance on handling delimiters for style values with no RFC6570 equivalent that already need to be percent-encoded when used as delimiters.
+
C.3 Non-RFC6570 Field Values and Combinations
+
Configurations with no direct [RFC6570] equivalent SHOULD also be handled according to RFC6570.
+Implementations MAY create a properly delimited URI Template with variables for individual names and values using RFC6570 regular or reserved expansion (based on allowReserved).
+
This includes:
+
+
the styles pipeDelimited, spaceDelimited, and deepObject, which have no equivalents at all
+
the combination of the style form with allowReserved: true, which is not allowed because only one prefix operator can be used at a time
+
any parameter name that is not a legal RFC6570 variable name
+
+
The Parameter Object’s name field has a much more permissive syntax than RFC6570 variable name syntax.
+A parameter name that includes characters outside of the allowed RFC6570 variable character set MUST be percent-encoded before it can be used in a URI Template.
+
C.4 Examples
+
Let’s say we want to use the following data in a form query string, where formulas is exploded, and words is not:
when expanded with the data given earlier, we get:
+
?a=x%2By&b=x%2Fy&c=x%5Ey&words=math,is,fun
+
+
C.4.2 Expansion with Non-RFC6570-Supported Options
+
But now let’s say that (for some reason), we really want that / in the b formula to show up as-is in the query string, and we want our words to be space-separated like in a written phrase.
+To do that, we’ll add allowReserved: true to formulas, and change to style: "spaceDelimited" for words:
We can’t combine the ? and + RFC6570 prefixes, and there’s no way with RFC6570 to replace the , separator with a space character.
+So we need to restructure the data to fit a manually constructed URI Template that passes all of the pieces through the right sort of expansion.
+
Here is one such template, using a made-up convention of words.0 for the first entry in the words value, words.1 for the second, and words.2 for the third:
RFC6570 mentions the use of . “to indicate name hierarchy in substructures,” but does not define any specific naming convention or behavior for it.
+Since the . usage is not automatic, we’ll need to construct an appropriate input structure for this new template.
+
We’ll also need to pre-process the values for formulas because while / and most other reserved characters are allowed in the query string by RFC3986, [, ], and #are not, and &, =, and + all have special behavior in the application/x-www-form-urlencoded format, which is what we are using in the query string.
+
Setting allowReserved: true does not make reserved characters that are not allowed in URIs allowed, it just allows them to be passed through expansion unchanged.
+Therefore, any tooling still needs to percent-encode those characters because reserved expansion will not do it, but it will leave the percent-encoded triples unchanged.
+See also Appendix E for further guidance on percent-encoding and form media types, including guidance on handling the delimiter characters for spaceDelimited, pipeDelimited, and deepObject in parameter names and values.
+
So here is our data structure that arranges the names and values to suit the template above, where values for formulas have []#&=+ pre-percent encoded (although only + appears in this example):
Expanding our manually assembled template with our restructured data yields the following query string:
+
?a=x%2By&b=x/y&c=x%5Ey&words=math%20is%20fun
+
+
The / and the pre-percent-encoded %2B have been left alone, but the disallowed ^ character (inside a value) and space characters (in the template but outside of the expanded variables) were percent-encoded.
+
C.4.3 Undefined Values and Manual URI Template Construction
+
Care must be taken when manually constructing templates to handle the values that RFC6570 considers to be undefined correctly:
+
formulas: {}
+words:
+-hello
+-world
+
+
Using this data with our original RFC6570-friendly URI Template, {?formulas*,words}, produces the following:
+
?words=hello,world
+
+
This means that the manually constructed URI Template and restructured data need to leave out the formulas object entirely so that the words parameter is the first and only parameter in the query string.
+
Restructured data:
+
words.0:hello
+words.1:world
+
+
Manually constructed URI Template:
+
?words={words.0} {words.1}
+
+
Result:
+
?words=hello%20world
+
+
C.4.4 Illegal Variable Names as Parameter Names
+
In this example, the heart emoji is not legal in URI Template names (or URIs):
We can’t just pass ❤️: "love!" to an RFC6570 implementation.
+Instead, we have to pre-percent-encode the name (which is a six-octet UTF-8 sequence) in both the data and the URI Template:
+
"%E2%9D%A4%EF%B8%8F":love!
+
+
{?%E2%9D%A4%EF%B8%8F}
+
+
This will expand to the result:
+
?%E2%9D%A4%EF%B8%8F=love%21
+
+
D. Appendix D: Serializing Headers and Cookies
+
[RFC6570]'s percent-encoding behavior is not always appropriate for in: "header" and in: "cookie" parameters.
+In many cases, it is more appropriate to use content with a media type such as text/plain and require the application to assemble the correct string.
+
For both [RFC6265] cookies and HTTP headers using the [RFC8941] structured fields syntax, non-ASCII content is handled using base64 encoding (contentEncoding: "base64").
+Note that the standard base64-encoding alphabet includes non-URL-safe characters that are percent-encoded by RFC6570 expansion; serializing values through both encodings is NOT RECOMMENDED.
+While contentEncoding also supports the base64url encoding, which is URL-safe, the header and cookie RFCs do not mention this encoding.
+
Most HTTP headers predate the structured field syntax, and a comprehensive assessment of their syntax and encoding rules is well beyond the scope of this specification.
+While [RFC8187] recommends percent-encoding HTTP (header or trailer) field parameters, these parameters appear after a ; character.
+With style: "simple", that delimiter would itself be percent-encoded, violating the general HTTP field syntax.
+
Using style: "form" with in: "cookie" is ambiguous for a single value, and incorrect for multiple values.
+This is true whether the multiple values are the result of using explode: true or not.
+
This style is specified to be equivalent to RFC6570 form expansion which includes the ? character (see Appendix C for more details), which is not part of the cookie syntax.
+However, examples of this style in past versions of this specification have not included the ? prefix, suggesting that the comparison is not exact.
+Because implementations that rely on an RFC6570 implementation and those that perform custom serialization based on the style example will produce different results, it is implementation-defined as to which of the two results is correct.
+
For multiple values, style: "form" is always incorrect as name=value pairs in cookies are delimited by ; (a semicolon followed by a space character) rather than &.
+
E. Appendix E: Percent-Encoding and Form Media Types
+
NOTE: In this section, the application/x-www-form-urlencoded and multipart/form-data media types are abbreviated as form-urlencoded and form-data, respectively, for readability.
+
Percent-encoding is used in URIs and media types that derive their syntax from URIs.
+This process is concerned with three sets of characters, the names of which vary among specifications but are defined as follows for the purposes of this section:
+
+
unreserved characters do not need to be percent-encoded; while it is safe to percent-encode them, doing so produces a URI that is not normalized
+
reserved characters either have special behavior in the URI syntax (such as delimiting components) or are reserved for other specifications that need to define special behavior (e.g. form-urlencoded defines special behavior for =, &, and +)
+
unsafe characters are known to cause problems when parsing URIs in certain environments
+
+
Unless otherwise specified, this section uses RFC3986’s definition of reserved and unreserved, and defines the unsafe set as all characters not included in either of those sets.
+
E.1 Percent-Encoding and form-urlencoded
+
Each URI component (such as the query string) considers some of the reserved characters to be unsafe, either because they serve as delimiters between the components (e.g. #), or (in the case of [ and ]) were historically considered globally unsafe but were later given reserved status for limited purposes.
+
Reserved characters with no special meaning defined within a component can be left un-percent encoded.
+However, other specifications can define special meanings, requiring percent-encoding for those characters outside of the additional special meanings.
+
The form-urlencoded media type defines special meanings for = and & as delimiters, and + as the replacement for the space character (instead of its percent-encoded form of %20).
+This means that while these three characters are reserved-but-allowed in query strings by RFC3986, they must be percent-encoded in form-urlencoded query strings except when used for their form-urlencoded purposes; see Appendix C for an example of handling + in form values.
+
E.2 Percent-Encoding and form-data
+
[RFC7578] Section 2 suggests RFC3986-based percent-encoding as a mechanism to keep text-based per-part header data such as file names within the ASCII character set.
+This suggestion was not part of older (pre-2015) specifications for form-data, so care must be taken to ensure interoperability.
+
The form-data media type allows arbitrary text or binary data in its parts, so percent-encoding is not needed and is likely to cause interoperability problems unless the Content-Type of the part is defined to require it.
+
E.3 Generating and Validating URIs and form-urlencoded Strings
+
URI percent encoding and the form-urlencoded media type have complex specification histories spanning multiple revisions and, in some cases, conflicting claims of ownership by different standards bodies.
+Unfortunately, these specifications each define slightly different percent-encoding rules, which need to be taken into account if the URIs or form-urlencoded message bodies will be subject to strict validation.
+(Note that many URI parsers do not perform validation by default.)
+
This specification normatively cites the following relevant standards:
Style-based serialization is used in the Parameter Object when schema is present, and in the Encoding Object when at least one of style, explode, or allowReserved is present.
+See Appendix C for more details of RFC6570’s two different approaches to percent-encoding, including an example involving +.
+
Content-based serialization is defined by the Media Type Object, and used with the Parameter Object when the content field is present, and with the Encoding Object based on the contentType field when the fields style, explode, and allowReserved are absent.
+Each part is encoded based on the media type (e.g. text/plain or application/json), and must then be percent-encoded for use in a form-urlencoded string.
+
Note that content-based serialization for form-data does not expect or require percent-encoding in the data, only in per-part header values.
+
E.3.1 Interoperability with Historical Specifications
+
In most cases, generating query strings in strict compliance with [RFC3986] is sufficient to pass validation (including JSON Schema’s format: "uri" and format: "uri-reference"), but some form-urlencoded implementations still expect the slightly more restrictive [RFC1738] rules to be used.
+
Since all RFC1738-compliant URIs are compliant with RFC3986, applications needing to ensure historical interoperability SHOULD use RFC1738’s rules.
+
E.3.2 Interoperability with Web Browser Environments
+
WHATWG is a web browser-oriented standards group that has defined a “URL Living Standard” for parsing and serializing URLs in a browser context, including parsing and serializing form-urlencoded data.
+WHATWG’s percent-encoding rules for query strings are different depending on whether the query string is being treated as form-urlencoded (where it requires more percent-encoding than [RFC1738]) or as part of the generic syntax, where it allows characters that [RFC3986] forbids.
+
Implementations needing maximum compatibility with web browsers SHOULD use WHATWG’s form-urlencoded percent-encoding rules.
+However, they SHOULD NOT rely on WHATWG’s less stringent generic query string rules, as the resulting URLs would fail RFC3986 validation, including JSON Schema’s format: uri and format: uri-reference.
+
E.4 Decoding URIs and form-urlencoded Strings
+
The percent-decoding algorithm does not care which characters were or were not percent-decoded, which means that URIs percent-encoded according to any specification will be decoded correctly.
+
Similarly, all form-urlencoded decoding algorithms simply add +-for-space handling to the percent-decoding algorithm, and will work regardless of the encoding specification used.
+
However, care must be taken to use form-urlencoded decoding if + represents a space, and to use regular percent-decoding if + represents itself as a literal value.
+
E.5 Percent-Encoding and Illegal or Reserved Delimiters
+
The [, ], |, and space characters, which are used as delimiters for the deepObject, pipeDelimited, and spaceDelimited styles, respectively, all MUST be percent-encoded to comply with [RFC3986].
+This requires users to pre-encode the character(s) in some other way in parameter names and values to distinguish them from the delimiter usage when using one of these styles.
+
The space character is always illegal and encoded in some way by all implementations of all versions of the relevant standards.
+While one could use the form-urlencoded convention of + to distinguish spaces in parameter names and values from spaceDelimited delimiters encoded as %20, the specifications define the decoding as a single pass, making it impossible to distinguish the different usages in the decoded result.
+
Some environments use [, ], and possibly | unencoded in query strings without apparent difficulties, and WHATWG’s generic query string rules do not require percent-encoding them.
+Code that relies on leaving these delimiters unencoded, while using regular percent-encoding for them within names and values, is not guaranteed to be interoperable across all implementations.
+
For maximum interoperability, it is RECOMMENDED to either define and document an additional escape convention while percent-encoding the delimiters for these styles, or to avoid these styles entirely.
+The exact method of additional encoding/escaping is left to the API designer, and is expected to be performed before serialization and encoding described in this specification, and reversed after this specification’s encoding and serialization steps are reversed.
+This keeps it outside of the processes governed by this specification.
+
F. Appendix F: Resolving Security Requirements in a Referenced Document
+
This appendix shows how to retrieve an HTTP-accessible multi-document OpenAPI Description (OAD) and resolve a Security Requirement Object in the referenced (non-entry) document. See Resolving Implicit Connections for more information.
+
First, the entry document is where parsing begins. It defines the MySecurity security scheme to be JWT-based, and it defines a Path Item as a reference to a component in another document:
This entry document references another document, other, without using a file extension. This gives the client the flexibility to choose an acceptable format on a resource-by-resource basis, assuming both representations are available:
In the other document, the referenced path item has a Security Requirement for a Security Scheme, MySecurity. The same Security Scheme exists in the original entry document. As outlined in Resolving Implicit Connections, MySecurity is resolved with an implementation-defined behavior. However, documented in that section, it is RECOMMENDED that tools resolve component names from the entry document. As with all implementation-defined behavior, it is important to check tool documentation to determine which behavior is supported.
JSON Schema: A Media Type for Describing JSON Documents. Draft 2020-12. Austin Wright; Henry Andrews; Ben Hutton; Greg Dennis. Internet Engineering Task Force (IETF). 8 December 2020. Internet-Draft. URL: https://datatracker.ietf.org/doc/html/draft-bhutton-json-schema-00
