# jsonx It's modified version of [encoding/json](https://golang.org/pkg/encoding/json/) which enables extra map field (with `jsonx:"true"` tag) to catch all other fields not declared in the struct. `jsonx` is a code name for internal use and not related to [JSONx](https://tools.ietf.org/html/draft-rsalz-jsonx-00). Example ([Run on playgroud](https://play.golang.org/p/TZi0JeHYG69)) ```go package main import ( "encoding/json" "fmt" "github.com/matterbridge/msgraph.go/jsonx" ) type Extra struct { X string Y int Extra map[string]interface{} `json:"-" jsonx:"true"` } func main() { var x1, x2 Extra b := []byte(`{"X":"123","Y":123,"A":"123","B":123}`) fmt.Printf("\nUnmarshal input: %s\n", string(b)) json.Unmarshal(b, &x1) fmt.Printf(" json.Unmarshal: %#v\n", x1) jsonx.Unmarshal(b, &x2) fmt.Printf("jsonx.Unmarshal: %#v\n", x2) x := Extra{X: "456", Y: 456, Extra: map[string]interface{}{"A": "456", "B": 456}} fmt.Printf("\nMarshal input: %#v\n", x) b1, _ := json.Marshal(x) fmt.Printf(" json.Marshal: %s\n", string(b1)) b2, _ := jsonx.Marshal(x) fmt.Printf("jsonx.Marshal: %s\n", string(b2)) } ``` Result ```text Unmarshal input: {"X":"123","Y":123,"A":"123","B":123} json.Unmarshal: main.Extra{X:"123", Y:123, Extra:map[string]interface {}(nil)} jsonx.Unmarshal: main.Extra{X:"123", Y:123, Extra:map[string]interface {}{"A":"123", "B":123}} Marshal input: main.Extra{X:"456", Y:456, Extra:map[string]interface {}{"A":"456", "B":456}} json.Marshal: {"X":"456","Y":456} jsonx.Marshal: {"X":"456","Y":456,"A":"456","B":456} ```