uvelichitel

Или всё же единственный нормальный вариант - это играться с fish?

package main

import (
	"fmt"
	"encoding/json"
	"log"
)

func main() {
	bodyBytes := []byte(`{"ok":true,"result":[{"update_id":715296593,
"message":{"message_id":5,"from":{"id":362268798,"is_bot":false,"first_name":"\u041a\u043e\u0442\ud83d\udd25","username":".....","language_code":"ru"},"chat":{"id":362268798,"first_name":"\u041a\u043e\u0442\ud83d\udd25","username":"....","type":"private"},"date":1604728384,"text":"/start","entities":[{"offset":0,"length":6,"type":"bot_command"}]}}]}`)

	var data map[string]interface{}
	err := json.Unmarshal(bodyBytes, &data)
	if err != nil {
		log.Fatal(err)
	}
	
	result, ok := data["result"].([]interface{})
	if !ok {
		log.Fatal("Failed to type-cast result")
	}
	firstResult, ok := result[0].(map[string]interface{})
	if !ok {
		log.Fatal("Failed to type-cast first result")
	}
	message, ok := firstResult["message"].(map[string]interface{})
	if !ok {
		log.Fatal("Failed to type-cast message")
	}
	chat, ok := message["chat"].(map[string]interface{})
	if !ok {
		log.Fatal("Failed to type-cast chat")
	}

	fmt.Println("id =", chat["id"])
	fmt.Println("type = ", chat["type"])
	fmt.Println("username = ", chat["username"])
	fmt.Println("first_name = ", chat["first_name"])
}

package main

import (
	"fmt"
	"encoding/json"
	"log"
)

type Response struct {
	Results []Result `json:"result"`
}

type Result struct {
	Message Message `json:"message"`
}

type Message struct {
	Chat Chat `json:"chat"`
}

type Chat struct {
	 ID int `json:"id"`
	 FirstName string `json:"first_name"`
	 UserName string `json:"username"`
	 Type string `json:"type"`
}

func main() {
	bodyBytes := []byte(`{"ok":true,"result":[{"update_id":715296593,
"message":{"message_id":5,"from":{"id":362268798,"is_bot":false,"first_name":"\u041a\u043e\u0442\ud83d\udd25","username":".....","language_code":"ru"},"chat":{"id":362268798,"first_name":"\u041a\u043e\u0442\ud83d\udd25","username":"....","type":"private"},"date":1604728384,"text":"/start","entities":[{"offset":0,"length":6,"type":"bot_command"}]}}]}`)

	var response Response
	err := json.Unmarshal(bodyBytes, &response)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println("id =", response.Results[0].Message.Chat.ID)
	fmt.Println("type = ", response.Results[0].Message.Chat.Type)
	fmt.Println("username = ", response.Results[0].Message.Chat.UserName)
	fmt.Println("first_name = ", response.Results[0].Message.Chat.FirstName)
}