Grouping routes

Route groups let you organize related routes under a shared URL prefix. This is useful for:

• API versioning — group all v1 endpoints under /v1 and v2 endpoints under /v2.
• Shared middleware — apply authentication, logging, or rate-limiting to an entire set of routes at once instead of attaching middleware to every route individually.
• Code organization — keep related handlers visually grouped in your source code.

Basic grouping

package main

import (
  "net/http"

  "github.com/gin-gonic/gin"
)

func loginEndpoint(c *gin.Context) {
  c.JSON(http.StatusOK, gin.H{"action": "login"})
}

func submitEndpoint(c *gin.Context) {
  c.JSON(http.StatusOK, gin.H{"action": "submit"})
}

func readEndpoint(c *gin.Context) {
  c.JSON(http.StatusOK, gin.H{"action": "read"})
}

func main() {
  router := gin.Default()

  // Simple group: v1
  {
    v1 := router.Group("/v1")
    v1.POST("/login", loginEndpoint)
    v1.POST("/submit", submitEndpoint)
    v1.POST("/read", readEndpoint)
  }

  // Simple group: v2
  {
    v2 := router.Group("/v2")
    v2.POST("/login", loginEndpoint)
    v2.POST("/submit", submitEndpoint)
    v2.POST("/read", readEndpoint)
  }

  router.Run(":8080")
}

Applying middleware to a group

You can pass middleware to router.Group() or call Use() on a group. Every route in that group will run the middleware before its handler.

// AuthRequired is a placeholder for your auth middleware.
func AuthRequired() gin.HandlerFunc {
  return func(c *gin.Context) {
    // ... check token, session, etc.
    c.Next()
  }
}

func main() {
  router := gin.Default()

  // Public routes -- no auth required
  public := router.Group("/api")
  {
    public.GET("/health", healthCheck)
  }

  // Private routes -- auth middleware applied to the whole group
  private := router.Group("/api")
  private.Use(AuthRequired())
  {
    private.GET("/profile", getProfile)
    private.POST("/settings", updateSettings)
  }

  router.Run(":8080")
}

Nested groups

Groups can be nested to build deeper URL hierarchies while keeping middleware scoped appropriately.

/api

func main() {
  router := gin.Default()

  api := router.Group("/api")
  {
    // /api/v1
    v1 := api.Group("/v1")
    {
      // /api/v1/users
      users := v1.Group("/users")
      users.GET("/", listUsers)
      users.GET("/:id", getUser)

      // /api/v1/posts
      posts := v1.Group("/posts")
      posts.GET("/", listPosts)
      posts.GET("/:id", getPost)
    }
  }

  router.Run(":8080")
}

Each level inherits the prefix of its parent, so the final routes become /api/v1/users/, /api/v1/users/:id, and so on.