Persist a bounded immutable proposal without mutating provider infrastructure

curl --request POST \
  --url http://127.0.0.1:18000/api/v1/optimization/campaigns \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'Idempotency-Key: <idempotency-key>' \
  --data '{
  "proposal": {}
}'

import requests

url = "http://127.0.0.1:18000/api/v1/optimization/campaigns"

payload = { "proposal": {} }
headers = {
    "Idempotency-Key": "<idempotency-key>",
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {
    'Idempotency-Key': '<idempotency-key>',
    Authorization: 'Bearer <token>',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({proposal: {}})
};

fetch('http://127.0.0.1:18000/api/v1/optimization/campaigns', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "http://127.0.0.1:18000/api/v1/optimization/campaigns"

	payload := strings.NewReader("{\n  \"proposal\": {}\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Idempotency-Key", "<idempotency-key>")
	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

{}

{
  "error": {
    "code": "<string>",
    "message": "<string>",
    "category": "<string>",
    "remediation": "<string>",
    "request_id": "<string>",
    "retryable": true
  }
}