Swagger

Hertz middleware to automatically generate RESTful API documentation with Swagger 2.0.

The implementation of the swagger extension refers to the implementation of Gin.

Usage

Add comments to your API source code, See Declarative Comments Format.
Download Swag for Go by using:

go get install executables needs to work with GOPATH mode.

go get github.com/swaggo/swag/cmd/swag

Starting in Go 1.17,installing executables with go get is deprecated. go install may be used instead:

go install github.com/swaggo/swag/cmd/swag@latest

Run the Swag at your Go project root path(for instance ~/root/go-project-name), Swag will parse comments and generate required files(docs folder and docs/doc.go) at ~/root/go-project-name/docs.

swag init

swag init with options(All options can be viewed via swag init -h).

swag init --parseDependency --parseInternal --parseDepth 5 --instanceName "swagger"

Options	Default	Description
parseInternal	false	Parse go files in internal packages.
parseDependency	false	Parse go files inside dependency folder.
parseDepth	100	Dependency parse depth.If you know the depth of the data structure to be parsed, it is recommended to use `parseDepth`, the swag command execution time will be greatly reduced.
instanceName	“swagger”	The instance name of the swagger document. If multiple different swagger instances should be deployed on one hertz router, ensure that each instance has a unique name.

Download hertz-swagger by using:

go get github.com/hertz-contrib/swagger
go get github.com/swaggo/files

Import following in your code:

import "github.com/hertz-contrib/swagger" // hertz-swagger middleware
import "github.com/swaggo/files" // swagger embed files

Example

Now assume you have implemented a simple api as following:

func PingHandler(ctx context.Context, c *app.RequestContext) {
    c.JSON(200, map[string]string{
        "ping": "pong",
    })
}

So how to use hertz-swagger on api above? Just follow the following guide.

Add Comments for apis and main function with hertz-swagger rules like following:

// PingHandler TestHandler
// @Summary TestSummary
// @Description TestDescription
// @Accept application/json
// @Produce application/json
// @Router /ping [get]
func PingHandler(ctx context.Context, c *app.RequestContext) {
    c.JSON(200, map[string]string{
        "ping": "pong",
    })
}

Use swag init command to generate a docs, docs generated will be stored at docs/.
Import the generated docs package into the current project: I assume your project named github.com/go-project-name/docs.

import (
   docs "github.com/go-project-name/docs"
)

Build your application and after that, go to http://localhost:8888/swagger/index.html ,you to see your Swagger UI.
The full code and folder relatives here:

package main

import (
   "context"

   "github.com/cloudwego/hertz/pkg/app"
   "github.com/cloudwego/hertz/pkg/app/server"
   "github.com/hertz-contrib/swagger"
   _ "github.com/hertz-contrib/swagger/example/basic/docs"
   swaggerFiles "github.com/swaggo/files"
)

// PingHandler Testhandler
// @Summary TestSummary
// @Description TestDescription
// @Accept application/json
// @Produce application/json
// @Router /ping [get]
func PingHandler(ctx context.Context, c *app.RequestContext) {
	c.JSON(200, map[string]string{
		"ping": "pong",
	})
}

// @title HertzTest
// @version 1.0
// @description This is a demo using Hertz.

// @contact.name hertz-contrib
// @contact.url https://github.com/hertz-contrib

// @license.name Apache 2.0
// @license.url http://www.apache.org/licenses/LICENSE-2.0.html

// @host localhost:8888
// @BasePath /
// @schemes http
func main() {
	h := server.Default()

	h.GET("/ping", PingHandler)

	url := swagger.URL("http://localhost:8888/swagger/doc.json") // The url pointing to API definition
	h.GET("/swagger/*any", swagger.WrapHandler(swaggerFiles.Handler, url))

	h.Spin()
}

Demo project tree, swag init is run at relative ..

.
├── docs
│   ├── docs.go
│   ├── swagger.json
│   └── swagger.yaml
├── go.mod
├── go.sum
└── main.go

Multiple APIs

This feature was introduced in swag v1.7.9.

Configuration

You can configure Swagger using different configuration options.

func main() {
	h := server.Default()

	h.GET("/ping", PingHandler)

	url := swagger.URL("http://localhost:8888/swagger/doc.json") // The url pointing to API definition
	h.GET("/swagger/*any", swagger.WrapHandler(swaggerFiles.Handler, url, swagger.DefaultModelsExpandDepth(-1)))
	h.Spin()
}

Option	Type	Default	Description
URL	string	“doc.json”	URL pointing to API definition
DocExpansion	string	“list”	Controls the default expansion setting for the operations and tags. It can be ’list’ (expands only the tags), ‘full’ (expands the tags and operations) or ’none’ (expands nothing).
DeepLinking	bool	true	If set to true, enables deep linking for tags and operations. See the Deep Linking documentation for more information.
DefaultModelsExpandDepth	int	1	Default expansion depth for models (set to -1 completely hide the models).
PersistAuthorization	bool	false	If set to true, it persists authorization data and it would not be lost on browser close/refresh.
Oauth2DefaultClientID	string	""	If set, it’s used to prepopulate the client_id field of the OAuth2 Authorization dialog.

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Last modified October 14, 2025 : chore: use bootstrap from npm (#1441) (be381bb)