Get JSON in POST in kemal - json

Question

What I want is a POST request in kemal where the body has a certain number of keys/values that I want to access and then an arbitrary JSON Object that I just want to stringify and pass on and later parse back to JSON.
My problem is that I apparently can't get the types right.
Think of a potential JSON body like this:
{
"endpoint": "http://example.com",
"interval": 500,
"payload": {
"something": "else",
"more": {
"embedded": 1
}
}
}
Now what I've been trying to do is the following:
require "kemal"
post "/schedule" do |env|
endpoint = env.params.json["endpoint"].as(String)
interval = env.params.json["interval"].as(Int64)
payload = String.from_json(env.params.json["payload"].as(JSON::Any))
# ... move things along
env.response.content_type = "application/json"
{ id: id }.to_json
end
Kemal.run
Now apparently what I seem to be getting when accessing "payload" is something of type Hash(String, JSON::Type), which confuses me a bit.
Any ideas how I'd be able to just get a sub-JSON from the request body, transform it to String and back to JSON?

Answer 1

Updated: payload is a type of JSON::Type. Casting and then calling .to_json does the trick.
require "kemal"
post "/schedule" do |env|
endpoint = env.params.json["endpoint"].as(String)
interval = env.params.json["interval"].as(Int64)
payload = env.params.json["payload"].as(JSON::Type)
env.response.content_type = "application/json"
payload.to_json
end
Kemal.run