Decline a paid milestone item of the next order

curl --request POST \
  --url https://api.fluid.app/api/checkout/v2026-04/subscriptions/{token}/milestone-declines \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "decline_key": "3f9a1c0e7b2d4a6f8e1c3b5d7a9f0e2c"
}
'

import requests

url = "https://api.fluid.app/api/checkout/v2026-04/subscriptions/{token}/milestone-declines"

payload = { "decline_key": "3f9a1c0e7b2d4a6f8e1c3b5d7a9f0e2c" }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({decline_key: '3f9a1c0e7b2d4a6f8e1c3b5d7a9f0e2c'})
};

fetch('https://api.fluid.app/api/checkout/v2026-04/subscriptions/{token}/milestone-declines', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.fluid.app/api/checkout/v2026-04/subscriptions/{token}/milestone-declines",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'decline_key' => '3f9a1c0e7b2d4a6f8e1c3b5d7a9f0e2c'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

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

func main() {

	url := "https://api.fluid.app/api/checkout/v2026-04/subscriptions/{token}/milestone-declines"

	payload := strings.NewReader("{\n  \"decline_key\": \"3f9a1c0e7b2d4a6f8e1c3b5d7a9f0e2c\"\n}")

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

	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))

}

HttpResponse<String> response = Unirest.post("https://api.fluid.app/api/checkout/v2026-04/subscriptions/{token}/milestone-declines")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"decline_key\": \"3f9a1c0e7b2d4a6f8e1c3b5d7a9f0e2c\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.fluid.app/api/checkout/v2026-04/subscriptions/{token}/milestone-declines")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"decline_key\": \"3f9a1c0e7b2d4a6f8e1c3b5d7a9f0e2c\"\n}"

response = http.request(request)
puts response.read_body

{
  "milestones": {
    "upcoming": [
      {
        "product_title": "Dunder Mifflin Mug",
        "variant_title": "White",
        "image_url": "https://cdn.example.com/mug.png",
        "quantity": 1,
        "gift": true,
        "price_label": null,
        "occurrence": {
          "type": "order",
          "order_number": 6
        },
        "decline_key": null
      }
    ],
    "next_milestone": null,
    "paid_total": 0
  },
  "meta": {
    "request_id": "6f1c2a9e-3b7d-4e58-9a21-c4d8e0b7f312",
    "timestamp": "2026-10-12T15:22:08Z"
  }
}

{
  "message": "<string>"
}

{
  "error_message": "<string>",
  "error_code": "invalid_params",
  "errors": "<string>",
  "meta": {
    "request_id": "<string>",
    "timestamp": "2023-11-07T05:31:56Z",
    "code": "<string>",
    "blocked_date": "2026-11-30",
    "blocked_day": 30,
    "allowed_date": "2026-11-28",
    "payment_uuid": "<string>",
    "error_details": [
      {
        "code": "<string>",
        "field": "<string>",
        "payment": "not_attempted",
        "message": "<string>"
      }
    ],
    "coded_recovery": true
  }
}

{
  "error_message": "The next order is being built; try again in a few minutes",
  "error_code": "billing_in_progress",
  "errors": {},
  "meta": {
    "request_id": "6f1c2a9e-3b7d-4e58-9a21-c4d8e0b7f312",
    "timestamp": "2026-10-12T15:22:08Z"
  }
}

{
  "error_message": "<string>",
  "error_code": "invalid_params",
  "errors": "<string>",
  "meta": {
    "request_id": "<string>",
    "timestamp": "2023-11-07T05:31:56Z",
    "code": "<string>",
    "blocked_date": "2026-11-30",
    "blocked_day": 30,
    "allowed_date": "2026-11-28",
    "payment_uuid": "<string>",
    "error_details": [
      {
        "code": "<string>",
        "field": "<string>",
        "payment": "not_attempted",
        "message": "<string>"
      }
    ],
    "coded_recovery": true
  }
}