# swag
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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).
## Contents
- [Getting started](#getting-started)
- [Supported Web Frameworks](#supported-web-frameworks)
- [How to use it with Gin](#how-to-use-it-with-gin)
- [Implementation Status](#implementation-status)
- [Declarative Comments Format](#declarative-comments-format)
- [General API Info](##general-api-info)
- [API Operation](#api-operation)
- [Security](#security)
- [Examples](#examples)
- [Descriptions over multiple lines](#descriptions-over-multiple-lines)
- [User defined structure with an array type](#user-defined-structure-with-an-array-type)
- [Add a headers in response](#add-a-headers-in-response)
- [Use multiple path params](#use-multiple-path-params)
- [Example value of struct](#example-value-of-struct)
- [Description of struct](#description-of-struct)
- [Override swagger type of a struct field](#Override-swagger-type-of-a-struct-field)
- [Add extension info to struct field](#add-extension-info-to-struct-field)
- [How to using security annotations](#how-to-using-security-annotations)
- [About the Project](#about-the-project)
## Getting started
1. Add comments to your API source code, See [Declarative Comments Format](#declarative-comments-format).
2. Download swag by using:
```sh
$ go get -u github.com/swaggo/swag/cmd/swag
```
Or download the pre-compiled binaries binray form [release page](https://github.com/swaggo/swag/releases).
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
```
Make sure to import the generated `docs/docs.go` so that your specific configuration gets `init`'ed. If your General API annotations do not live in `main.go`, you can let swag know with `-g` flag.
```sh
swag init -g http/api.go
```
## swag cli
```sh
$ 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: "./")
--propertyStrategy value, -p value Property Naming Strategy like snakecase,camelcase,pascalcase (default: "camelcase")
--output value, -o value Output directory for al the generated files(swagger.json, swagger.yaml and doc.go) (default: "./docs")
--parseVendor Parse go files in 'vendor' folder, disabled by default --output value, -o value Output directory for al the generated files(swagger.json, swagger.yaml and doc.go) (default: "./docs")
```
## 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
// @Header 200 {string} Token "qwerty"
// @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
// @Header 200 {string} Token "qwerty"
// @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
# Declarative Comments Format
## 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 |
| schemes | The transfer protocol for the operation that separated by spaces. | // @schemes http https |
## 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` |
| header | Header in response that separated by spaces. `return code`,`{param type}`,`data type`,`comment` |
| router | Path definition that separated by spaces. `path`,`[httpMethod]` |
## Mime Types
`swag` accepts all MIME Types which are in the correct format, that is, match `*/*`.
Besides that, `swag` also accepts aliases for some MIME Types as follows:
| Alias | MIME Type |
|-----------------------|-----------------------------------|
| json | application/json |
| xml | text/xml |
| plain | text/plain |
| html | text/html |
| mpfd | multipart/form-data |
| x-www-form-urlencoded | application/x-www-form-urlencoded |
| json-api | application/vnd.api+json |
| json-stream | application/x-json-stream |
| octet-stream | application/octet-stream |
| png | image/png |
| jpeg | image/jpeg |
| gif | image/gif |
## 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
## 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 |
## 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.
format | `string` | The extending format for the previously mentioned [`type`](#parameterType). See [Data Type Formats](#dataTypeFormat) for further details.
### Future
Field Name | Type | Description
---|:---:|---
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: - `csv` - comma separated values `foo,bar`.
- `ssv` - space separated values `foo bar`.
- `tsv` - tab separated values `foo\tbar`.
- `pipes` - pipe separated values
foo|bar. - `multi` - corresponds to multiple parameter instances instead of multiple values for a single instance `foo=bar&foo=baz`. This is valid only for parameters [`in`](#parameterIn) "query" or "formData".
Default value is `csv`.
## Examples
### Descriptions over multiple lines
You can add descriptions spanning multiple lines in either the general api description or routes definitions like so:
```go
// @description This is the first line
// @description This is the second line
// @description And so forth.
```
### User defined structure with an array type
```go
// @Success 200 {array} model.Account <-- This is a user defined struct.
```
```go
package model
type Account struct {
ID int `json:"id" example:"1"`
Name string `json:"name" example:"account name"`
}
```
### Add a headers in response
```go
// @Success 200 {string} string "ok"
// @Header 200 {string} Location "/entity/1"
// @Header 200 {string} Token "qwerty"
```
### Use multiple path params
```go
/// ...
// @Param group_id path int true "Group ID"
// @Param account_id path int true "Account ID"
// ...
// @Router /examples/groups/{group_id}/accounts/{account_id} [get]
```
### Example value of struct
```go
type Account struct {
ID int `json:"id" example:"1"`
Name string `json:"name" example:"account name"`
PhotoUrls []string `json:"photo_urls" example:"http://test/image/1.jpg,http://test/image/2.jpg"`
}
```
### Description of struct
```go
type Account struct {
// ID this is userid
ID int `json:"id"`
Name string `json:"name"` // This is Name
}
```
### Override swagger type of a struct field
```go
type TimestampTime struct {
time.Time
}
///implement encoding.JSON.Marshaler interface
func (t *TimestampTime) MarshalJSON() ([]byte, error) {
bin := make([]byte, 16)
bin = strconv.AppendInt(bin[:0], t.Time.Unix(), 10)
return bin, nil
}
func (t *TimestampTime) UnmarshalJSON(bin []byte) error {
v, err := strconv.ParseInt(string(bin), 10, 64)
if err != nil {
return err
}
t.Time = time.Unix(v, 0)
return nil
}
///
type Account struct {
// Override primitive type by simply specifying it via `swaggertype` tag
ID sql.NullInt64 `json:"id" swaggertype:"integer"`
// Override struct type to a primitive type 'integer' by specifying it via `swaggertype` tag
RegisterTime TimestampTime `json:"register_time" swaggertype:"primitive,integer"`
// Array types can be overridden using "array," format
Coeffs []big.Float `json:"coeffs" swaggertype:"array,number"`
}
```
### Add extension info to struct field
```go
type Account struct {
ID int `json:"id" extensions:"x-nullable,x-abc=def"` // extensions fields must start with "x-"
}
```
generate swagger doc as follows:
```go
"Account": {
"type": "object",
"properties": {
"id": {
"type": "string",
"x-nullable": true,
"x-abc": "def"
}
}
}
```
### How to using security annotations
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]
```
## About the Project
This project was inspired by [yvasiyarov/swagger](https://github.com/yvasiyarov/swagger) but we simplified the usage and added support a variety of [web frameworks](#supported-web-frameworks). Gopher image source is [tenntenn/gopher-stickers](https://github.com/tenntenn/gopher-stickers). It has licenses [creative commons licensing](http://creativecommons.org/licenses/by/3.0/deed.en).
## Contributors
This project exists thanks to all the people who contribute. [[Contribute](CONTRIBUTING.md)].
## Backers
Thank you to all our backers! 🙏 [[Become a backer](https://opencollective.com/swag#backer)]
## Sponsors
Support this project by becoming a sponsor. Your logo will show up here with a link to your website. [[Become a sponsor](https://opencollective.com/swag#sponsor)]
## License
[](https://app.fossa.io/projects/git%2Bgithub.com%2Fswaggo%2Fswag?ref=badge_large)