The OpenAPI FAQ provides good explanations for OpenAPI spec. Therefore, we have listed some descriptions below, which give a good overview about this topic.
In case that further knowledge is required, visit openapis.org which provides plenty of useful information.
What is OpenAPI?
«There is the OpenAPI Specification (OAS), a technical specification that describes certain APIs, and there is the OpenAPI Initiative (OAI), an organization that enables specifications like OAS to thrive. The OAS defines a standard, programming language-agnostic interface description for REST 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 OAS, 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 OAS removes guesswork in calling a service. The OpenAPI Initiative (OAI) was created by a consortium of forward-looking industry experts who recognize the immense value of standardizing on how APIs are described. As an open governance structure under the Linux Foundation, the OAI is focused on creating, evolving and promoting a vendor neutral description format. The OpenAPI Specification was based on the rebranded Swagger 2.0 specification, donated by SmartBear Software in 2015. » |
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What are the main benefits of the OpenAPI Specification?
«Business benefits are:
Technical benefits are:
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Example OpenAPI specification
This example illustrates how an OpenAPI specification could look like:
{
"openapi": "3.0.0",
"info": {
"version": "1.0.0",
"title": "Swagger Petstore",
"license": {
"name": "MIT"
}
},
"servers": [
{
"url": "http://petstore.swagger.io/v1"
}
],
"paths": {
"/pets": {
"get": {
"summary": "List all pets",
"operationId": "listPets",
"tags": [
"pets"
],
"parameters": [
{
"name": "limit",
"in": "query",
"description": "How many items to return at one time (max 100)",
"required": false,
"schema": {
"type": "integer",
"format": "int32"
}
}
],
"responses": {
"200": {
"description": "A paged array of pets",
"headers": {
"x-next": {
"description": "A link to the next page of responses",
"schema": {
"type": "string"
}
}
},
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Pets"
}
}
}
},
"default": {
"description": "unexpected error",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}
}
},
"post": {
"summary": "Create a pet",
"operationId": "createPets",
"tags": [
"pets"
],
"responses": {
"201": {
"description": "Null response"
},
"default": {
"description": "unexpected error",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}
}
}
},
"/pets/{petId}": {
"get": {
"summary": "Info for a specific pet",
"operationId": "showPetById",
"tags": [
"pets"
],
"parameters": [
{
"name": "petId",
"in": "path",
"required": true,
"description": "The id of the pet to retrieve",
"schema": {
"type": "string"
}
}
],
"responses": {
"200": {
"description": "Expected response to a valid request",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Pet"
}
}
}
},
"default": {
"description": "unexpected error",
"content": {
"application/json": {
"schema": {
"$ref": "#/components/schemas/Error"
}
}
}
}
}
}
}
},
"components": {
"schemas": {
"Pet": {
"type": "object",
"required": [
"id",
"name"
],
"properties": {
"id": {
"type": "integer",
"format": "int64"
},
"name": {
"type": "string"
},
"tag": {
"type": "string"
}
}
},
"Pets": {
"type": "array",
"items": {
"$ref": "#/components/schemas/Pet"
}
},
"Error": {
"type": "object",
"required": [
"code",
"message"
],
"properties": {
"code": {
"type": "integer",
"format": "int32"
},
"message": {
"type": "string"
}
}
}
}
}
}