Free stem presets guide

import time
from datetime import datetime, timezone

import requests

API_URL = "https://api.wav.com/api/public/v2/Extraction"
API_KEY = "<API_KEY>"


def extract(audio_url, preset="6_stems", webhook_url=None):
    data = {"audio_url": audio_url, "stem_preset": preset}
    if webhook_url:
        data["webhook_url"] = webhook_url
    response = requests.post(
        API_URL, headers={"Authorization": API_KEY}, data=data, timeout=60
    )
    response.raise_for_status()
    return response.json()


def seconds_until(timestamp):
    reset_at = datetime.fromisoformat(timestamp.replace("Z", "+00:00"))
    return max((reset_at - datetime.now(timezone.utc)).total_seconds(), 0) + 1


def extract_all_free(audio_urls, preset="6_stems", webhook_url=None):
    results = []
    for audio_url in audio_urls:
        result = extract(audio_url, preset, webhook_url)
        results.append(result)
        if result["is_free_promo"]:
            print(f"{result['task_id']}: free")
        else:
            print(f"{result['task_id']}: charged {result['credit_estimate']}")

        hour_left = result.get("free_generations_remaining_hour")
        day_left = result.get("free_generations_remaining_day")
        if hour_left is None:
            continue  # No promotion applies to this account or date.
        if hour_left == 0 or day_left == 0:
            wait = seconds_until(result["free_quota_resets_at"])
            print(f"Free quota used up. Waiting {wait:.0f}s.")
            time.sleep(wait)
    return results


extract_all_free(
    ["<TRACK_1_URL>", "<TRACK_2_URL>", "<TRACK_3_URL>"],
    webhook_url="https://example.com/webhook",
)

const API_URL = "https://api.wav.com/api/public/v2/Extraction";
const API_KEY = "<API_KEY>";

async function extract(audioUrl, preset = "6_stems", webhookUrl) {
  const form = new FormData();
  form.append("audio_url", audioUrl);
  form.append("stem_preset", preset);
  if (webhookUrl) form.append("webhook_url", webhookUrl);

  const response = await fetch(API_URL, {
    method: "POST",
    headers: { Authorization: API_KEY },
    body: form,
  });
  if (!response.ok) throw new Error(`${response.status}: ${await response.text()}`);
  return response.json();
}

const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms));

async function extractAllFree(audioUrls, preset = "6_stems", webhookUrl) {
  const results = [];
  for (const audioUrl of audioUrls) {
    const result = await extract(audioUrl, preset, webhookUrl);
    results.push(result);
    console.log(
      `${result.task_id}: ${result.is_free_promo ? "free" : `charged ${result.credit_estimate}`}`
    );

    const hourLeft = result.free_generations_remaining_hour;
    const dayLeft = result.free_generations_remaining_day;
    if (hourLeft == null) continue; // No promotion applies to this account or date.
    if (hourLeft === 0 || dayLeft === 0) {
      const wait = Math.max(Date.parse(result.free_quota_resets_at) - Date.now(), 0) + 1000;
      console.log(`Free quota used up. Waiting ${Math.round(wait / 1000)}s.`);
      await sleep(wait);
    }
  }
  return results;
}

extractAllFree(
  ["<TRACK_1_URL>", "<TRACK_2_URL>", "<TRACK_3_URL>"],
  "6_stems",
  "https://example.com/webhook"
).catch(console.error);