wrapper for https://developers.google.com/poly/develop/toolkit-unity https://qiita.com/nekomimi-daimao/items/e3332b1af52c390987da

PolyTasker.cs

using System;
using System.Threading.Tasks;
using PolyToolkit;
using UnityEngine;

namespace NekomimiDaimao.Poly
{
    public static class PolyTasker
    {
        public static Task<PolyListAssetsResult> SearchListAssetsAsync(PolyListAssetsRequest assetsRequest)
        {
            var tcs = new TaskCompletionSource<PolyListAssetsResult>();
            PolyApi.ListAssets(assetsRequest, result =>
            {
                if (result.Ok)
                {
                    tcs.SetResult(result.Value);
                }
                else
                {
                    tcs.SetException(new Exception(result.Status.errorMessage));
                }
            });
            return tcs.Task;
        }

        public static Task<PolyListAssetsResult> SearchUserListAssetsAsync(PolyListUserAssetsRequest assetsRequest)
        {
            var tcs = new TaskCompletionSource<PolyListAssetsResult>();
            PolyApi.ListUserAssets(assetsRequest, result =>
            {
                if (result.Ok)
                {
                    tcs.SetResult(result.Value);
                }
                else
                {
                    tcs.SetException(new Exception(result.Status.errorMessage));
                }
            });
            return tcs.Task;
        }


        public static Task<PolyListAssetsResult> SearchLikedListAssetsAsync(PolyListLikedAssetsRequest assetsRequest)
        {
            var tcs = new TaskCompletionSource<PolyListAssetsResult>();
            PolyApi.ListLikedAssets(assetsRequest, result =>
            {
                if (result.Ok)
                {
                    tcs.SetResult(result.Value);
                }
                else
                {
                    tcs.SetException(new Exception(result.Status.errorMessage));
                }
            });
            return tcs.Task;
        }

        public static Task<PolyAsset> FetchThumbnailAsync(PolyAsset asset, PolyFetchThumbnailOptions options)
        {
            var tcs = new TaskCompletionSource<PolyAsset>();
            PolyApi.FetchThumbnail(asset, options, (polyAsset, status) =>
            {
                if (status.ok)
                {
                    tcs.SetResult(polyAsset);
                }
                else
                {
                    tcs.SetException(new Exception(status.errorMessage));
                }
            });

            return tcs.Task;
        }

        public static Task<PolyAsset> GetAssetAsync(string name)
        {
            var tcs = new TaskCompletionSource<PolyAsset>();
            PolyApi.GetAsset(name, result =>
            {
                if (result.Ok)
                {
                    tcs.SetResult(result.Value);
                }
                else
                {
                    tcs.SetException(new Exception(result.Status.errorMessage));
                }
            });

            return tcs.Task;
        }


        public static Task<(GameObject obj, PolyAsset polyAsset)> ImportAsync(PolyAsset asset, PolyImportOptions? options = null)
        {
            var tcs = new TaskCompletionSource<(GameObject obj, PolyAsset polyAsset)>();
            PolyApi.Import(asset, options ?? PolyImportOptions.Default(), (polyAsset, result) =>
            {
                if (result.Ok)
                {
                    tcs.SetResult((result.Value.gameObject, polyAsset));
                }
                else
                {
                    tcs.SetException(new Exception(result.Status.errorMessage));
                }
            });
            return tcs.Task;
        }
    }
}