Automatically generate RESTful API documentation with Swagger 2.0 for Go.
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## Content - [Getting started](#getting-started) - [Go web frameworks](#supported-web-frameworks) - [Supported Web Frameworks](#supported-web-frameworks) - [How to use it with Gin](#how-to-use-it-with-gin) - [Implementation Status](#implementation-status) - [swag cli](#swag-cli) - [General API Info](#general-api-info) - [Security](#security) - [API Operation](#api-operation) - [TIPS](#tips) - [User defined structure with an array type](#user-defined-structure-with-an-array-type) - [Use multiple path params](#use-multiple-path-params) - [Example value of struct](#example-value-of-struct) - [Description of struct](#description-of-struct) - [About the Project](#about-the-project) ## Summary Swag converts Go annotations to Swagger Documentation 2.0. We've created a variety of plugins for popular [Go web frameworks](#supported-web-frameworks). This allows you to quickly integrate with an existing Go project (using Swagger UI). ## Examples [swaggo + gin](https://github.com/swaggo/swag/tree/master/example) ## Getting started 1. Add comments to your API source code, [See Declarative Comments Format](#general-api-info). 2. Download swag by using: ```sh $ go get -u github.com/swaggo/swag/cmd/swag ``` 3. Run `swag init` in the project's root folder which contains the `main.go` file. This will parse your comments and generate the required files (`docs` folder and `docs/docs.go`). ```sh $ swag init ``` 4. In order to serve these files, you can utilize one of our supported plugins. For go's core library, check out [net/http](https://github.com/swaggo/http-swagger). * Make sure to import the generated `docs/docs.go` so that your specific configuration gets `init`'ed. * If your General API annotation do not live in `main.go`, you can let swag know with `-g`. ```sh swag init -g http/api.go ``` ## Supported Web Frameworks - [gin](http://github.com/swaggo/gin-swagger) - [echo](http://github.com/swaggo/echo-swagger) - [buffalo](https://github.com/swaggo/buffalo-swagger) - [net/http](https://github.com/swaggo/http-swagger) ## How to use it with Gin Find the example source code [here](https://github.com/swaggo/swag/tree/master/example/celler). 1. After using `swag init` to generate Swagger 2.0 docs, import the following packages: ```go import "github.com/swaggo/gin-swagger" // gin-swagger middleware import "github.com/swaggo/gin-swagger/swaggerFiles" // swagger embed files ``` 2. Add [General API](#general-api-info) annotations in `main.go` code: ```go // @title Swagger Example API // @version 1.0 // @description This is a sample server celler server. // @termsOfService http://swagger.io/terms/ // @contact.name API Support // @contact.url http://www.swagger.io/support // @contact.email support@swagger.io // @license.name Apache 2.0 // @license.url http://www.apache.org/licenses/LICENSE-2.0.html // @host localhost:8080 // @BasePath /api/v1 // @securityDefinitions.basic BasicAuth // @securityDefinitions.apikey ApiKeyAuth // @in header // @name Authorization // @securitydefinitions.oauth2.application OAuth2Application // @tokenUrl https://example.com/oauth/token // @scope.write Grants write access // @scope.admin Grants read and write access to administrative information // @securitydefinitions.oauth2.implicit OAuth2Implicit // @authorizationurl https://example.com/oauth/authorize // @scope.write Grants write access // @scope.admin Grants read and write access to administrative information // @securitydefinitions.oauth2.password OAuth2Password // @tokenUrl https://example.com/oauth/token // @scope.read Grants read access // @scope.write Grants write access // @scope.admin Grants read and write access to administrative information // @securitydefinitions.oauth2.accessCode OAuth2AccessCode // @tokenUrl https://example.com/oauth/token // @authorizationurl https://example.com/oauth/authorize // @scope.admin Grants read and write access to administrative information func main() { r := gin.Default() c := controller.NewController() v1 := r.Group("/api/v1") { accounts := v1.Group("/accounts") { accounts.GET(":id", c.ShowAccount) accounts.GET("", c.ListAccounts) accounts.POST("", c.AddAccount) accounts.DELETE(":id", c.DeleteAccount) accounts.PATCH(":id", c.UpdateAccount) accounts.POST(":id/images", c.UploadAccountImage) } //... } r.GET("/swagger/*any", ginSwagger.WrapHandler(swaggerFiles.Handler)) r.Run(":8080") } //... ``` Additionally some general API info can be set dynamically. The generated code package `docs` exports `SwaggerInfo` variable which we can use to set the title, description, version, host and base path programatically. Example using Gin: ```go package main import ( "github.com/gin-gonic/gin" "github.com/swaggo/gin-swagger" "github.com/swaggo/gin-swagger/swaggerFiles" "./docs" // docs is generated by Swag CLI, you have to import it. ) // @contact.name API Support // @contact.url http://www.swagger.io/support // @contact.email support@swagger.io // @license.name Apache 2.0 // @license.url http://www.apache.org/licenses/LICENSE-2.0.html // @termsOfService http://swagger.io/terms/ func main() { // programatically set swagger info docs.SwaggerInfo.Title = "Swagger Example API" docs.SwaggerInfo.Description = "This is a sample server Petstore server." docs.SwaggerInfo.Version = "1.0" docs.SwaggerInfo.Host = "petstore.swagger.io" docs.SwaggerInfo.BasePath = "/v2" r := gin.New() // use ginSwagger middleware to serve the API docs r.GET("/swagger/*any", ginSwagger.WrapHandler(swaggerFiles.Handler)) r.Run() } ``` 3. Add [API Operation](#api-operation) annotations in `controller` code ``` go package controller import ( "fmt" "net/http" "strconv" "github.com/gin-gonic/gin" "github.com/swaggo/swag/example/celler/httputil" "github.com/swaggo/swag/example/celler/model" ) // ShowAccount godoc // @Summary Show a account // @Description get string by ID // @ID get-string-by-int // @Accept json // @Produce json // @Param id path int true "Account ID" // @Success 200 {object} model.Account // @Failure 400 {object} httputil.HTTPError // @Failure 404 {object} httputil.HTTPError // @Failure 500 {object} httputil.HTTPError // @Router /accounts/{id} [get] func (c *Controller) ShowAccount(ctx *gin.Context) { id := ctx.Param("id") aid, err := strconv.Atoi(id) if err != nil { httputil.NewError(ctx, http.StatusBadRequest, err) return } account, err := model.AccountOne(aid) if err != nil { httputil.NewError(ctx, http.StatusNotFound, err) return } ctx.JSON(http.StatusOK, account) } // ListAccounts godoc // @Summary List accounts // @Description get accounts // @Accept json // @Produce json // @Param q query string false "name search by q" // @Success 200 {array} model.Account // @Failure 400 {object} httputil.HTTPError // @Failure 404 {object} httputil.HTTPError // @Failure 500 {object} httputil.HTTPError // @Router /accounts [get] func (c *Controller) ListAccounts(ctx *gin.Context) { q := ctx.Request.URL.Query().Get("q") accounts, err := model.AccountsAll(q) if err != nil { httputil.NewError(ctx, http.StatusNotFound, err) return } ctx.JSON(http.StatusOK, accounts) } //... ``` ```console $ swag init ``` 4.Run your app, and browse to http://localhost:8080/swagger/index.html. You will see Swagger 2.0 Api documents as shown below:  ## Implementation Status [Swagger 2.0 document](https://swagger.io/docs/specification/2-0/basic-structure/) - [x] Basic Structure - [x] API Host and Base Path - [x] Paths and Operations - [x] Describing Parameters - [x] Describing Request Body - [x] Describing Responses - [x] MIME Types - [x] Authentication - [x] Basic Authentication - [x] API Keys - [x] Adding Examples - [x] File Upload - [x] Enums - [x] Grouping Operations With Tags - [ ] Swagger Extensions # swag cli ```console $ swag init -h NAME: swag init - Create docs.go USAGE: swag init [command options] [arguments...] OPTIONS: --generalInfo value, -g value Go file path in which 'swagger general API Info' is written (default: "main.go") --dir value, -d value Directory you want to parse (default: "./") --swagger value, -s value Output the swagger conf for json and yaml (default: "./docs/swagger") --propertyStrategy value, -p value Property Naming Strategy like snakecase,camelcase,pascalcase (default: "camelcase") ``` # General API Info **Example** [celler/main.go](https://github.com/swaggo/swag/blob/master/example/celler/main.go) | annotation | description | example | |-----------------------|-------------------------------------------------------------------------------------------------|-----------------------------------------------------------------| | title | **Required.** The title of the application. | // @title Swagger Example API | | version | **Required.** Provides the version of the application API. | // @version 1.0 | | description | A short description of the application. | // @description This is a sample server celler server. | | tag.name | Name of a tag. | // @tag.name This is the name of the tag | | tag.description | Description of the tag | // @tag.description Cool Description | | tag.docs.url | Url of the external Documentation of the tag | // @tag.docs.url https://example.com | | tag.docs.descripiton | Description of the external Documentation of the tag | // @tag.docs.descirption Best example documentation | | termsOfService | The Terms of Service for the API. | // @termsOfService http://swagger.io/terms/ | | contact.name | The contact information for the exposed API. | // @contact.name API Support | | contact.url | The URL pointing to the contact information. MUST be in the format of a URL. | // @contact.url http://www.swagger.io/support | | contact.email | The email address of the contact person/organization. MUST be in the format of an email address.| // @contact.email support@swagger.io | | license.name | **Required.** The license name used for the API. | // @license.name Apache 2.0 | | license.url | A URL to the license used for the API. MUST be in the format of a URL. | // @license.url http://www.apache.org/licenses/LICENSE-2.0.html | | host | The host (name or ip) serving the API. | // @host localhost:8080 | | BasePath | The base path on which the API is served. | // @BasePath /api/v1 | ## Security | annotation | description | parameters | example | |-----------------------------------------|------------------------------------------------------------------------------------------------|-----------------------------------|--------------------------------------------------------------| | securitydefinitions.basic | [Basic](https://swagger.io/docs/specification/2-0/authentication/basic-authentication/) auth. | | // @securityDefinitions.basic BasicAuth | | securitydefinitions.apikey | [API key](https://swagger.io/docs/specification/2-0/authentication/api-keys/) auth. | in, name | // @securityDefinitions.apikey ApiKeyAuth | | securitydefinitions.oauth2.application | [OAuth2 application](https://swagger.io/docs/specification/authentication/oauth2/) auth. | tokenUrl, scope | // @securitydefinitions.oauth2.application OAuth2Application | | securitydefinitions.oauth2.implicit | [OAuth2 implicit](https://swagger.io/docs/specification/authentication/oauth2/) auth. | authorizationUrl, scope | // @securitydefinitions.oauth2.implicit OAuth2Implicit | | securitydefinitions.oauth2.password | [OAuth2 password](https://swagger.io/docs/specification/authentication/oauth2/) auth. | tokenUrl, scope | // @securitydefinitions.oauth2.password OAuth2Password | | securitydefinitions.oauth2.accessCode | [OAuth2 access code](https://swagger.io/docs/specification/authentication/oauth2/) auth. | tokenUrl, authorizationUrl, scope | // @securitydefinitions.oauth2.accessCode OAuth2AccessCode | | parameters annotation | example | |-----------------------|----------------------------------------------------------| | in | // @in header | | name | // @name Authorization | | tokenUrl | // @tokenUrl https://example.com/oauth/token | | authorizationurl | // @authorizationurl https://example.com/oauth/authorize | | scope.hoge | // @scope.write Grants write access | # API Operation **Example** [celler/controller](https://github.com/swaggo/swag/tree/master/example/celler/controller) | annotation | description | |--------------------|----------------------------------------------------------------------------------------------------------------------------| | description | A verbose explanation of the operation behavior. | | id | A unique string used to identify the operation. Must be unique among all API operations. | | tags | A list of tags to each API operation that separated by commas. | | summary | A short summary of what the operation does. | | accept | A list of MIME types the APIs can consume. Value MUST be as described under [Mime Types](#mime-types). | | produce | A list of MIME types the APIs can produce. Value MUST be as described under [Mime Types](#mime-types). | | param | Parameters that separated by spaces. `param name`,`param type`,`data type`,`is mandatory?`,`comment` `attribute(optional)` | | security | [Security](#security) to each API operation. | | success | Success response that separated by spaces. `return code`,`{param type}`,`data type`,`comment` | | failure | Failure response that separated by spaces. `return code`,`{param type}`,`data type`,`comment` | | router | Path definition that separated by spaces. `path`,`[httpMethod]` | ## Mime Types | Mime Type | annotation | |-----------------------------------|-----------------------------------------------------------| | application/json | application/json, json | | text/xml | text/xml, xml | | text/plain | text/plain, plain | | html | text/html, html | | multipart/form-data | multipart/form-data, mpfd | | application/x-www-form-urlencoded | application/x-www-form-urlencoded, x-www-form-urlencoded | | application/vnd.api+json | application/vnd.api+json, json-api | | application/x-json-stream | application/x-json-stream, json-stream | | application/octet-stream | application/octet-stream, octet-stream | | image/png | image/png, png | | image/jpeg | image/jpeg, jpeg | | image/gif | image/gif, gif | ## Security General API info. ```go // @securityDefinitions.basic BasicAuth // @securitydefinitions.oauth2.application OAuth2Application // @tokenUrl https://example.com/oauth/token // @scope.write Grants write access // @scope.admin Grants read and write access to administrative information ``` Each API operation. ```go // @Security ApiKeyAuth ``` Make it AND condition ```go // @Security ApiKeyAuth // @Security OAuth2Application[write, admin] ``` ## Param Type - object (struct) - string (string) - integer (int, uint, uint32, uint64) - number (float32) - boolean (bool) - array ## Data Type - string (string) - integer (int, uint, uint32, uint64) - number (float32) - boolean (bool) - user defined struct ## Attribute ```go // @Param enumstring query string false "string enums" Enums(A, B, C) // @Param enumint query int false "int enums" Enums(1, 2, 3) // @Param enumnumber query number false "int enums" Enums(1.1, 1.2, 1.3) // @Param string query string false "string valid" minlength(5) maxlength(10) // @Param int query int false "int valid" mininum(1) maxinum(10) // @Param default query string false "string default" default(A) ``` It also works for the struct fields: ```go type Foo struct { Bar string `minLength:"4" maxLength:"16"` Baz int `minimum:"10" maximum:"20" default:"15"` Qux []string `enums:"foo,bar,baz"` } ``` ### Available Field Name | Type | Description ---|:---:|--- default | * | Declares the value of the parameter that the server will use if none is provided, for example a "count" to control the number of results per page might default to 100 if not supplied by the client in the request. (Note: "default" has no meaning for required parameters.) See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-6.2. Unlike JSON Schema this value MUST conform to the defined [`type`](#parameterType) for this parameter. maximum | `number` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.1.2. minimum | `number` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.1.3. maxLength | `integer` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.2.1. minLength | `integer` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.2.2. enums | [\*] | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.5.1. ### Future Field Name | Type | Description ---|:---:|--- format | `string` | The extending format for the previously mentioned [`type`](#parameterType). See [Data Type Formats](#dataTypeFormat) for further details. multipleOf | `number` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.1.1. pattern | `string` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.2.3. maxItems | `integer` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.3.2. minItems | `integer` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.3.3. uniqueItems | `boolean` | See https://tools.ietf.org/html/draft-fge-json-schema-validation-00#section-5.3.4. collectionFormat | `string` | Determines the format of the array if type array is used. Possible values are:foo|bar.