Context

Fox handlers use *fox.Context, a thin wrapper around Gin’s *gin.Context. It embeds Gin’s context, so Gin methods such as Query, Param, JSON, Abort, and GetHeader are available directly, while Fox adds request body caching, TraceID helpers, logger access, and context.Context compatibility.

Getting Context

Fox handlers can optionally accept a *fox.Context parameter:

r.GET("/path", func(c *fox.Context) (any, error) {
    // Access context
    return response, nil
})

Gin middleware still uses *gin.Context:

func MyMiddleware() gin.HandlerFunc {
    return func(c *gin.Context) {
        c.Set("user_id", 123)
        c.Next()
    }
}

Request Data

Query Parameters

name := c.Query("name")              // Get query param
page := c.DefaultQuery("page", "1")  // With default value

Path Parameters

r.GET("/user/:id", func(c *gin.Context) {
    id := c.Param("id")
})

Headers

token := c.GetHeader("Authorization")
userAgent := c.Request.UserAgent()

Request Body

var data map[string]any
c.ShouldBindJSON(&data)

Fox also provides RequestBody() for reading and caching the raw request body. It restores the body so later binding can read it again:

body, err := c.RequestBody()

Client IP

ip := c.ClientIP()

Response

JSON Response

c.JSON(200, gin.H{
    "message": "success",
})

String Response

c.String(200, "Hello, World!")

HTML Response

c.HTML(200, "index.html", gin.H{
    "title": "Home",
})

Redirect

c.Redirect(302, "/new-path")

Status Code

c.Status(204) // No Content

Context Data

Set Value

c.Set("user_id", 123)

Get Value

userID := c.GetInt("user_id")
value, exists := c.Get("key")

Must Get

userID := c.MustGet("user_id").(int)

File Handling

Single File Upload

file, _ := c.FormFile("file")
c.SaveUploadedFile(file, "./uploads/"+file.Filename)

Multiple Files

form, _ := c.MultipartForm()
files := form.File["files"]

for _, file := range files {
    c.SaveUploadedFile(file, "./uploads/"+file.Filename)
}

Serve File

c.File("./assets/image.png")

Cookies

Set Cookie

c.SetCookie(
    "session_id",           // name
    "abc123",               // value
    3600,                   // maxAge (seconds)
    "/",                    // path
    "example.com",          // domain
    false,                  // secure
    true,                   // httpOnly
)

Get Cookie

value, err := c.Cookie("session_id")

Abort

Stop processing and return:

if !isAuthenticated(c) {
    c.JSON(401, gin.H{"error": "Unauthorized"})
    c.Abort()
    return
}

Fox-Specific Methods

Get Logger

c.Logger.Info("Processing request")

Get TraceID

traceID := c.TraceID()

Context Interface

*fox.Context implements the standard context methods by delegating to c.Request.Context():

select {
case <-c.Done():
    return nil, c.Err()
default:
}

value := c.Value(myKey)

Next Steps

• Router API - Router configuration
• Middleware - Custom middleware