myData := []byte({"username": "john", "age": 30})
When json unmarshal the above data, int type is converted to float64 thus causing schema validation error. So when user is defining avro schema, schema can't have int type. It should be double rather than int.

https://github.com/hamba/avro#types-conversions

Any workaround to solve this? otherwise we should mention it on the UI as well

Any workaround to solve this? otherwise we should mention it on the UI as well

I can think of the below solution. But this solution converts int to int64. Still we need to add note in the UI.
So i reckon leave it as it is and add note in the UI.

https://go.dev/play/p/SkG6qlolz1B

myData := `{"username": "John", "age": 30}`
var m map[string]interface{}

dec := json.NewDecoder(strings.NewReader(myData))
dec.UseNumber()

err := dec.Decode(&m)
if err != nil {
     log.Fatal(err)
}

m["age"], err = m["age"].(json.Number).Int64()
if err != nil {
	log.Fatal(err)
}

Ok totally agree

Is this thing happening on other SDKs as well or only in Go? if no so let's add a comment about it in the readme file of Go sdk it is enough

Any workaround to solve this? otherwise we should mention it on the UI as well

In protobuf we allow users to send map[string]interface{} in order people won't have to hole the proto file locally, is it possible here as well?

Yes. I've added it now.