Closes #3073 (#3077)

* Initial implementation of announce with diff * Add missing logic pieces * Change in logic * Fix checksums * Add deduplication logic * Update SetPart.cs * Use standalone endpoint for diff * Use different hashcode impl * Update AssetForListing.cs * Misc * Push all the changes for this to finally work * Use original index rather than self-calculated ASFB makes some calculations based on index, it's better for us to have holes rather than hiding skipped items. * Handle edge case of no assets after deduplication * Remove dead code * Address trim warnings * Misc optimization
2024-11-10 07:04:27 +00:00 · 2023-11-29 00:08:16 +01:00 · 2023-11-29 00:08:16 +01:00 · 36ae066c65
commit 36ae066c65
parent 8cf2d1bc94
17 changed files with 771 additions and 156 deletions
--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Backend.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Backend.cs
@ -22,7 +22,10 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Linq;
 using System.Net;
+using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using ArchiSteamFarm.Core;
 using ArchiSteamFarm.IPC.Responses;
@ -38,16 +41,15 @@ using SteamKit2;
 namespace ArchiSteamFarm.OfficialPlugins.ItemsMatcher;

 internal static class Backend {
-	internal static async Task<BasicResponse?> AnnounceForListing(ulong steamID, WebBrowser webBrowser, IReadOnlyList<AssetForListing> inventory, IReadOnlyCollection<Asset.EType> acceptedMatchableTypes, uint totalInventoryCount, bool matchEverything, string tradeToken, string? nickname = null, string? avatarHash = null) {
+	internal static async Task<BasicResponse?> AnnounceDiffForListing(WebBrowser webBrowser, ulong steamID, ICollection<AssetForListing> inventory, string inventoryChecksum, IReadOnlyCollection<Asset.EType> acceptedMatchableTypes, uint totalInventoryCount, bool matchEverything, string tradeToken, ICollection<AssetForListing> inventoryRemoved, string? previousInventoryChecksum, string? nickname = null, string? avatarHash = null) {
+		ArgumentNullException.ThrowIfNull(webBrowser);
+
 		if ((steamID == 0) || !new SteamID(steamID).IsIndividualAccount) {
 			throw new ArgumentOutOfRangeException(nameof(steamID));
 		}

-		ArgumentNullException.ThrowIfNull(webBrowser);
-
-		if ((inventory == null) || (inventory.Count == 0)) {
-			throw new ArgumentNullException(nameof(inventory));
-		}
+		ArgumentNullException.ThrowIfNull(inventory);
+		ArgumentException.ThrowIfNullOrEmpty(inventoryChecksum);

 		if ((acceptedMatchableTypes == null) || (acceptedMatchableTypes.Count == 0)) {
 			throw new ArgumentNullException(nameof(acceptedMatchableTypes));
@ -60,13 +62,58 @@ internal static class Backend {
 			throw new ArgumentOutOfRangeException(nameof(tradeToken));
 		}

-		Uri request = new(ArchiNet.URL, "/Api/Listing/Announce/v3");
+		ArgumentNullException.ThrowIfNull(inventoryRemoved);
+		ArgumentException.ThrowIfNullOrEmpty(previousInventoryChecksum);

-		AnnouncementRequest data = new(ASF.GlobalDatabase?.Identifier ?? Guid.NewGuid(), steamID, tradeToken, inventory, acceptedMatchableTypes, totalInventoryCount, matchEverything, ASF.GlobalConfig?.MaxTradeHoldDuration ?? GlobalConfig.DefaultMaxTradeHoldDuration, nickname, avatarHash);
+		Uri request = new(ArchiNet.URL, "/Api/Listing/AnnounceDiff");
+
+		AnnouncementDiffRequest data = new(ASF.GlobalDatabase?.Identifier ?? Guid.NewGuid(), steamID, inventory, inventoryChecksum, acceptedMatchableTypes, totalInventoryCount, matchEverything, ASF.GlobalConfig?.MaxTradeHoldDuration ?? GlobalConfig.DefaultMaxTradeHoldDuration, tradeToken, inventoryRemoved, previousInventoryChecksum, nickname, avatarHash);

 		return await webBrowser.UrlPost(request, data: data, requestOptions: WebBrowser.ERequestOptions.ReturnRedirections | WebBrowser.ERequestOptions.ReturnClientErrors | WebBrowser.ERequestOptions.CompressRequest).ConfigureAwait(false);
 	}

+	internal static async Task<BasicResponse?> AnnounceForListing(WebBrowser webBrowser, ulong steamID, ICollection<AssetForListing> inventory, string inventoryChecksum, IReadOnlyCollection<Asset.EType> acceptedMatchableTypes, uint totalInventoryCount, bool matchEverything, string tradeToken, string? nickname = null, string? avatarHash = null) {
+		ArgumentNullException.ThrowIfNull(webBrowser);
+
+		if ((steamID == 0) || !new SteamID(steamID).IsIndividualAccount) {
+			throw new ArgumentOutOfRangeException(nameof(steamID));
+		}
+
+		if ((inventory == null) || (inventory.Count == 0)) {
+			throw new ArgumentNullException(nameof(inventory));
+		}
+
+		ArgumentException.ThrowIfNullOrEmpty(inventoryChecksum);
+
+		if ((acceptedMatchableTypes == null) || (acceptedMatchableTypes.Count == 0)) {
+			throw new ArgumentNullException(nameof(acceptedMatchableTypes));
+		}
+
+		ArgumentOutOfRangeException.ThrowIfZero(totalInventoryCount);
+		ArgumentException.ThrowIfNullOrEmpty(tradeToken);
+
+		if (tradeToken.Length != BotConfig.SteamTradeTokenLength) {
+			throw new ArgumentOutOfRangeException(nameof(tradeToken));
+		}
+
+		Uri request = new(ArchiNet.URL, "/Api/Listing/Announce/v4");
+
+		AnnouncementRequest data = new(ASF.GlobalDatabase?.Identifier ?? Guid.NewGuid(), steamID, inventory, inventoryChecksum, acceptedMatchableTypes, totalInventoryCount, matchEverything, ASF.GlobalConfig?.MaxTradeHoldDuration ?? GlobalConfig.DefaultMaxTradeHoldDuration, tradeToken, nickname, avatarHash);
+
+		return await webBrowser.UrlPost(request, data: data, requestOptions: WebBrowser.ERequestOptions.ReturnRedirections | WebBrowser.ERequestOptions.ReturnClientErrors | WebBrowser.ERequestOptions.CompressRequest).ConfigureAwait(false);
+	}
+
+	internal static string GenerateChecksumFor(IList<AssetForListing> assetsForListings) {
+		if ((assetsForListings == null) || (assetsForListings.Count == 0)) {
+			throw new ArgumentNullException(nameof(assetsForListings));
+		}
+
+		string text = string.Join('|', assetsForListings.Select(static asset => asset.BackendHashCode));
+		byte[] bytes = Encoding.UTF8.GetBytes(text);
+
+		return Utilities.GenerateChecksumFor(bytes);
+	}
+
 	internal static async Task<(HttpStatusCode StatusCode, ImmutableHashSet<ListedUser> Users)?> GetListedUsersForMatching(Guid licenseID, Bot bot, WebBrowser webBrowser, IReadOnlyCollection<Asset> inventory, IReadOnlyCollection<Asset.EType> acceptedMatchableTypes) {
 		ArgumentOutOfRangeException.ThrowIfEqual(licenseID, Guid.Empty);
 		ArgumentNullException.ThrowIfNull(bot);
@ -97,6 +144,28 @@ internal static class Backend {
 		return (response.StatusCode, response.Content?.Result ?? ImmutableHashSet<ListedUser>.Empty);
 	}

+	internal static async Task<ObjectResponse<GenericResponse<ImmutableHashSet<SetPart>>>?> GetSetParts(WebBrowser webBrowser, ulong steamID, ICollection<Asset.EType> matchableTypes, ICollection<uint> realAppIDs, CancellationToken cancellationToken = default) {
+		ArgumentNullException.ThrowIfNull(webBrowser);
+
+		if ((steamID == 0) || !new SteamID(steamID).IsIndividualAccount) {
+			throw new ArgumentOutOfRangeException(nameof(steamID));
+		}
+
+		if ((matchableTypes == null) || (matchableTypes.Count == 0)) {
+			throw new ArgumentNullException(nameof(matchableTypes));
+		}
+
+		if ((realAppIDs == null) || (realAppIDs.Count == 0)) {
+			throw new ArgumentNullException(nameof(realAppIDs));
+		}
+
+		Uri request = new(ArchiNet.URL, "/Api/SetParts/Request");
+
+		SetPartsRequest data = new(ASF.GlobalDatabase?.Identifier ?? Guid.NewGuid(), steamID, matchableTypes, realAppIDs);
+
+		return await webBrowser.UrlPostToJsonObject<GenericResponse<ImmutableHashSet<SetPart>>, SetPartsRequest>(request, data: data, requestOptions: WebBrowser.ERequestOptions.ReturnRedirections | WebBrowser.ERequestOptions.ReturnClientErrors | WebBrowser.ERequestOptions.AllowInvalidBodyOnErrors | WebBrowser.ERequestOptions.CompressRequest, cancellationToken: cancellationToken).ConfigureAwait(false);
+	}
+
 	internal static async Task<BasicResponse?> HeartBeatForListing(Bot bot, WebBrowser webBrowser) {
 		ArgumentNullException.ThrowIfNull(bot);
 		ArgumentNullException.ThrowIfNull(webBrowser);
--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/BotCache.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/BotCache.cs
@ -0,0 +1,124 @@
+//     _                _      _  ____   _                           _____
+//    / \    _ __  ___ | |__  (_)/ ___| | |_  ___   __ _  _ __ ___  |  ___|__ _  _ __  _ __ ___
+//   / _ \  | '__|/ __|| '_ \ | |\___ \ | __|/ _ \ / _` || '_ ` _ \ | |_  / _` || '__|| '_ ` _ \
+//  / ___ \ | |  | (__ | | | || | ___) || |_|  __/| (_| || | | | | ||  _|| (_| || |   | | | | | |
+// /_/   \_\|_|   \___||_| |_||_||____/  \__|\___| \__,_||_| |_| |_||_|   \__,_||_|   |_| |_| |_|
+// |
+// Copyright 2015-2023 Łukasz "JustArchi" Domeradzki
+// Contact: JustArchi@JustArchi.net
+// |
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// |
+// http://www.apache.org/licenses/LICENSE-2.0
+// |
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System;
+using System.Globalization;
+using System.IO;
+using System.Threading.Tasks;
+using ArchiSteamFarm.Collections;
+using ArchiSteamFarm.Core;
+using ArchiSteamFarm.Helpers;
+using ArchiSteamFarm.Localization;
+using ArchiSteamFarm.OfficialPlugins.ItemsMatcher.Data;
+using JetBrains.Annotations;
+using Newtonsoft.Json;
+
+namespace ArchiSteamFarm.OfficialPlugins.ItemsMatcher;
+
+internal sealed class BotCache : SerializableFile {
+	[JsonProperty(Required = Required.DisallowNull)]
+	internal readonly ConcurrentList<AssetForListing> LastAnnouncedAssetsForListing = new();
+
+	internal string? LastAnnouncedTradeToken {
+		get => BackingLastAnnouncedTradeToken;
+
+		set {
+			if (BackingLastAnnouncedTradeToken == value) {
+				return;
+			}
+
+			BackingLastAnnouncedTradeToken = value;
+			Utilities.InBackground(Save);
+		}
+	}
+
+	[JsonProperty]
+	private string? BackingLastAnnouncedTradeToken;
+
+	private BotCache(string filePath) : this() {
+		ArgumentException.ThrowIfNullOrEmpty(filePath);
+
+		FilePath = filePath;
+	}
+
+	[JsonConstructor]
+	private BotCache() => LastAnnouncedAssetsForListing.OnModified += OnObjectModified;
+
+	[UsedImplicitly]
+	public bool ShouldSerializeBackingLastAnnouncedTradeToken() => !string.IsNullOrEmpty(BackingLastAnnouncedTradeToken);
+
+	[UsedImplicitly]
+	public bool ShouldSerializeLastAnnouncedAssetsForListing() => LastAnnouncedAssetsForListing.Count > 0;
+
+	protected override void Dispose(bool disposing) {
+		if (disposing) {
+			// Events we registered
+			LastAnnouncedAssetsForListing.OnModified -= OnObjectModified;
+		}
+
+		// Base dispose
+		base.Dispose(disposing);
+	}
+
+	internal static async Task<BotCache> CreateOrLoad(string filePath) {
+		ArgumentException.ThrowIfNullOrEmpty(filePath);
+
+		if (!File.Exists(filePath)) {
+			return new BotCache(filePath);
+		}
+
+		BotCache? botCache;
+
+		try {
+			string json = await File.ReadAllTextAsync(filePath).ConfigureAwait(false);
+
+			if (string.IsNullOrEmpty(json)) {
+				ASF.ArchiLogger.LogGenericError(string.Format(CultureInfo.CurrentCulture, Strings.ErrorIsEmpty, nameof(json)));
+
+				return new BotCache(filePath);
+			}
+
+			botCache = JsonConvert.DeserializeObject<BotCache>(json);
+		} catch (Exception e) {
+			ASF.ArchiLogger.LogGenericException(e);
+
+			return new BotCache(filePath);
+		}
+
+		if (botCache == null) {
+			ASF.ArchiLogger.LogNullError(botCache);
+
+			return new BotCache(filePath);
+		}
+
+		botCache.FilePath = filePath;
+
+		return botCache;
+	}
+
+	private async void OnObjectModified(object? sender, EventArgs e) {
+		if (string.IsNullOrEmpty(FilePath)) {
+			return;
+		}
+
+		await Save().ConfigureAwait(false);
+	}
+}
--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/AnnouncementDiffRequest.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/AnnouncementDiffRequest.cs
@ -0,0 +1,66 @@
+//     _                _      _  ____   _                           _____
+//    / \    _ __  ___ | |__  (_)/ ___| | |_  ___   __ _  _ __ ___  |  ___|__ _  _ __  _ __ ___
+//   / _ \  | '__|/ __|| '_ \ | |\___ \ | __|/ _ \ / _` || '_ ` _ \ | |_  / _` || '__|| '_ ` _ \
+//  / ___ \ | |  | (__ | | | || | ___) || |_|  __/| (_| || | | | | ||  _|| (_| || |   | | | | | |
+// /_/   \_\|_|   \___||_| |_||_||____/  \__|\___| \__,_||_| |_| |_||_|   \__,_||_|   |_| |_| |_|
+// |
+// Copyright 2015-2023 Łukasz "JustArchi" Domeradzki
+// Contact: JustArchi@JustArchi.net
+// |
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// |
+// http://www.apache.org/licenses/LICENSE-2.0
+// |
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using ArchiSteamFarm.Steam.Data;
+using ArchiSteamFarm.Steam.Storage;
+using Newtonsoft.Json;
+using SteamKit2;
+
+namespace ArchiSteamFarm.OfficialPlugins.ItemsMatcher.Data;
+
+internal sealed class AnnouncementDiffRequest : AnnouncementRequest {
+	[JsonProperty(Required = Required.Always)]
+	private readonly ImmutableHashSet<AssetForListing> InventoryRemoved;
+
+	[JsonProperty(Required = Required.Always)]
+	private readonly string PreviousInventoryChecksum;
+
+	internal AnnouncementDiffRequest(Guid guid, ulong steamID, ICollection<AssetForListing> inventory, string inventoryChecksum, IReadOnlyCollection<Asset.EType> matchableTypes, uint totalInventoryCount, bool matchEverything, byte maxTradeHoldDuration, string tradeToken, ICollection<AssetForListing> inventoryRemoved, string previousInventoryChecksum, string? nickname = null, string? avatarHash = null) : base(guid, steamID, inventory, inventoryChecksum, matchableTypes, totalInventoryCount, matchEverything, maxTradeHoldDuration, tradeToken, nickname, avatarHash) {
+		ArgumentOutOfRangeException.ThrowIfEqual(guid, Guid.Empty);
+
+		if ((steamID == 0) || !new SteamID(steamID).IsIndividualAccount) {
+			throw new ArgumentOutOfRangeException(nameof(steamID));
+		}
+
+		ArgumentNullException.ThrowIfNull(inventory);
+		ArgumentException.ThrowIfNullOrEmpty(inventoryChecksum);
+
+		if ((matchableTypes == null) || (matchableTypes.Count == 0)) {
+			throw new ArgumentNullException(nameof(matchableTypes));
+		}
+
+		ArgumentOutOfRangeException.ThrowIfZero(totalInventoryCount);
+		ArgumentException.ThrowIfNullOrEmpty(tradeToken);
+
+		if (tradeToken.Length != BotConfig.SteamTradeTokenLength) {
+			throw new ArgumentOutOfRangeException(nameof(tradeToken));
+		}
+
+		ArgumentNullException.ThrowIfNull(inventoryRemoved);
+		ArgumentException.ThrowIfNullOrEmpty(previousInventoryChecksum);
+
+		InventoryRemoved = inventoryRemoved.ToImmutableHashSet();
+		PreviousInventoryChecksum = previousInventoryChecksum;
+	}
+}
--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/AnnouncementRequest.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/AnnouncementRequest.cs
@ -30,7 +30,7 @@ using SteamKit2;

 namespace ArchiSteamFarm.OfficialPlugins.ItemsMatcher.Data;

-internal sealed class AnnouncementRequest {
+internal class AnnouncementRequest {
 	[JsonProperty]
 	private readonly string? AvatarHash;

@ -38,7 +38,10 @@ internal sealed class AnnouncementRequest {
 	private readonly Guid Guid;

 	[JsonProperty(Required = Required.Always)]
-	private readonly ImmutableList<AssetForListing> Inventory;
+	private readonly ImmutableHashSet<AssetForListing> Inventory;
+
+	[JsonProperty(Required = Required.Always)]
+	private readonly string InventoryChecksum;

 	[JsonProperty(Required = Required.Always)]
 	private readonly ImmutableHashSet<Asset.EType> MatchableTypes;
@ -61,33 +64,35 @@ internal sealed class AnnouncementRequest {
 	[JsonProperty(Required = Required.Always)]
 	private readonly string TradeToken;

-	internal AnnouncementRequest(Guid guid, ulong steamID, string tradeToken, IReadOnlyList<AssetForListing> inventory, IReadOnlyCollection<Asset.EType> matchableTypes, uint totalInventoryCount, bool matchEverything, byte maxTradeHoldDuration, string? nickname = null, string? avatarHash = null) {
+	internal AnnouncementRequest(Guid guid, ulong steamID, ICollection<AssetForListing> inventory, string inventoryChecksum, IReadOnlyCollection<Asset.EType> matchableTypes, uint totalInventoryCount, bool matchEverything, byte maxTradeHoldDuration, string tradeToken, string? nickname = null, string? avatarHash = null) {
 		ArgumentOutOfRangeException.ThrowIfEqual(guid, Guid.Empty);

 		if ((steamID == 0) || !new SteamID(steamID).IsIndividualAccount) {
 			throw new ArgumentOutOfRangeException(nameof(steamID));
 		}

-		ArgumentException.ThrowIfNullOrEmpty(tradeToken);
-
-		if (tradeToken.Length != BotConfig.SteamTradeTokenLength) {
-			throw new ArgumentOutOfRangeException(nameof(tradeToken));
-		}
-
 		if ((inventory == null) || (inventory.Count == 0)) {
 			throw new ArgumentNullException(nameof(inventory));
 		}

+		ArgumentException.ThrowIfNullOrEmpty(inventoryChecksum);
+
 		if ((matchableTypes == null) || (matchableTypes.Count == 0)) {
 			throw new ArgumentNullException(nameof(matchableTypes));
 		}

 		ArgumentOutOfRangeException.ThrowIfZero(totalInventoryCount);
+		ArgumentException.ThrowIfNullOrEmpty(tradeToken);
+
+		if (tradeToken.Length != BotConfig.SteamTradeTokenLength) {
+			throw new ArgumentOutOfRangeException(nameof(tradeToken));
+		}

 		Guid = guid;
 		SteamID = steamID;
 		TradeToken = tradeToken;
-		Inventory = inventory.ToImmutableList();
+		Inventory = inventory.ToImmutableHashSet();
+		InventoryChecksum = inventoryChecksum;
 		MatchableTypes = matchableTypes.ToImmutableHashSet();
 		MatchEverything = matchEverything;
 		MaxTradeHoldDuration = maxTradeHoldDuration;
--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/AssetForListing.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/AssetForListing.cs
@ -26,12 +26,21 @@ using Newtonsoft.Json;
 namespace ArchiSteamFarm.OfficialPlugins.ItemsMatcher.Data;

 internal sealed class AssetForListing : AssetInInventory {
+	[JsonProperty("i", Required = Required.Always)]
+	internal readonly uint Index;
+
 	[JsonProperty("l", Required = Required.Always)]
 	internal readonly ulong PreviousAssetID;

-	internal AssetForListing(Asset asset, ulong previousAssetID) : base(asset) {
+	internal string BackendHashCode => Index + "-" + PreviousAssetID + "-" + AssetID + "-" + ClassID + "-" + Rarity + "-" + RealAppID + "-" + Tradable + "-" + Type + "-" + Amount;
+
+	internal AssetForListing(Asset asset, uint index, ulong previousAssetID) : base(asset) {
 		ArgumentNullException.ThrowIfNull(asset);

+		Index = index;
 		PreviousAssetID = previousAssetID;
 	}
+
+	[JsonConstructor]
+	private AssetForListing() { }
 }
--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/AssetForMatching.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/AssetForMatching.cs
@ -26,9 +26,6 @@ using Newtonsoft.Json;
 namespace ArchiSteamFarm.OfficialPlugins.ItemsMatcher.Data;

 internal class AssetForMatching {
-	[JsonProperty("a", Required = Required.Always)]
-	internal readonly uint Amount;
-
 	[JsonProperty("c", Required = Required.Always)]
 	internal readonly ulong ClassID;

@ -44,6 +41,9 @@ internal class AssetForMatching {
 	[JsonProperty("p", Required = Required.Always)]
 	internal readonly Asset.EType Type;

+	[JsonProperty("a", Required = Required.Always)]
+	internal uint Amount { get; set; }
+
 	[JsonConstructor]
 	protected AssetForMatching() { }

--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/AssetInInventory.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/AssetInInventory.cs
@ -29,14 +29,14 @@ internal class AssetInInventory : AssetForMatching {
 	[JsonProperty("d", Required = Required.Always)]
 	internal readonly ulong AssetID;

+	[JsonConstructor]
+	protected AssetInInventory() { }
+
 	internal AssetInInventory(Asset asset) : base(asset) {
 		ArgumentNullException.ThrowIfNull(asset);

 		AssetID = asset.AssetID;
 	}

-	[JsonConstructor]
-	private AssetInInventory() { }
-
 	internal Asset ToAsset() => new(Asset.SteamAppID, Asset.SteamCommunityContextID, ClassID, Amount, tradable: Tradable, assetID: AssetID, realAppID: RealAppID, type: Type, rarity: Rarity);
 }
--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/SetPart.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/SetPart.cs
@ -0,0 +1,54 @@
+//     _                _      _  ____   _                           _____
+//    / \    _ __  ___ | |__  (_)/ ___| | |_  ___   __ _  _ __ ___  |  ___|__ _  _ __  _ __ ___
+//   / _ \  | '__|/ __|| '_ \ | |\___ \ | __|/ _ \ / _` || '_ ` _ \ | |_  / _` || '__|| '_ ` _ \
+//  / ___ \ | |  | (__ | | | || | ___) || |_|  __/| (_| || | | | | ||  _|| (_| || |   | | | | | |
+// /_/   \_\|_|   \___||_| |_||_||____/  \__|\___| \__,_||_| |_| |_||_|   \__,_||_|   |_| |_| |_|
+// |
+// Copyright 2015-2023 Łukasz "JustArchi" Domeradzki
+// Contact: JustArchi@JustArchi.net
+// |
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// |
+// http://www.apache.org/licenses/LICENSE-2.0
+// |
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System.Diagnostics.CodeAnalysis;
+using ArchiSteamFarm.Steam.Data;
+using Newtonsoft.Json;
+
+namespace ArchiSteamFarm.OfficialPlugins.ItemsMatcher.Data;
+
+#pragma warning disable CA1812 // False positive, the class is used during json deserialization
+[SuppressMessage("ReSharper", "ClassCannotBeInstantiated")]
+internal sealed class SetPart {
+#pragma warning disable CS0649 // False positive, the field is used during json deserialization
+	[JsonProperty("c", Required = Required.Always)]
+	internal readonly ulong ClassID;
+#pragma warning restore CS0649 // False positive, the field is used during json deserialization
+
+#pragma warning disable CS0649 // False positive, the field is used during json deserialization
+	[JsonProperty("r", Required = Required.Always)]
+	internal readonly Asset.ERarity Rarity;
+#pragma warning restore CS0649 // False positive, the field is used during json deserialization
+
+#pragma warning disable CS0649 // False positive, the field is used during json deserialization
+	[JsonProperty("e", Required = Required.Always)]
+	internal readonly uint RealAppID;
+#pragma warning restore CS0649 // False positive, the field is used during json deserialization
+
+#pragma warning disable CS0649 // False positive, the field is used during json deserialization
+	[JsonProperty("p", Required = Required.Always)]
+	internal readonly Asset.EType Type;
+#pragma warning restore CS0649 // False positive, the field is used during json deserialization
+
+	[JsonConstructor]
+	private SetPart() { }
+}
+#pragma warning restore CA1812 // False positive, the class is used during json deserialization
--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/SetPartsRequest.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/Data/SetPartsRequest.cs
@ -0,0 +1,64 @@
+//     _                _      _  ____   _                           _____
+//    / \    _ __  ___ | |__  (_)/ ___| | |_  ___   __ _  _ __ ___  |  ___|__ _  _ __  _ __ ___
+//   / _ \  | '__|/ __|| '_ \ | |\___ \ | __|/ _ \ / _` || '_ ` _ \ | |_  / _` || '__|| '_ ` _ \
+//  / ___ \ | |  | (__ | | | || | ___) || |_|  __/| (_| || | | | | ||  _|| (_| || |   | | | | | |
+// /_/   \_\|_|   \___||_| |_||_||____/  \__|\___| \__,_||_| |_| |_||_|   \__,_||_|   |_| |_| |_|
+// |
+// Copyright 2015-2023 Łukasz "JustArchi" Domeradzki
+// Contact: JustArchi@JustArchi.net
+// |
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// |
+// http://www.apache.org/licenses/LICENSE-2.0
+// |
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using ArchiSteamFarm.Steam.Data;
+using Newtonsoft.Json;
+using SteamKit2;
+
+namespace ArchiSteamFarm.OfficialPlugins.ItemsMatcher.Data;
+
+internal sealed class SetPartsRequest {
+	[JsonProperty(Required = Required.Always)]
+	internal readonly Guid Guid;
+
+	[JsonProperty(Required = Required.Always)]
+	internal readonly ImmutableHashSet<Asset.EType> MatchableTypes;
+
+	[JsonProperty(Required = Required.Always)]
+	internal readonly ImmutableHashSet<uint> RealAppIDs;
+
+	[JsonProperty(Required = Required.Always)]
+	internal readonly ulong SteamID;
+
+	internal SetPartsRequest(Guid guid, ulong steamID, ICollection<Asset.EType> matchableTypes, ICollection<uint> realAppIDs) {
+		ArgumentOutOfRangeException.ThrowIfEqual(guid, Guid.Empty);
+
+		if ((steamID == 0) || !new SteamID(steamID).IsIndividualAccount) {
+			throw new ArgumentOutOfRangeException(nameof(steamID));
+		}
+
+		if ((matchableTypes == null) || (matchableTypes.Count == 0)) {
+			throw new ArgumentNullException(nameof(matchableTypes));
+		}
+
+		if ((realAppIDs == null) || (realAppIDs.Count == 0)) {
+			throw new ArgumentNullException(nameof(realAppIDs));
+		}
+
+		Guid = guid;
+		SteamID = steamID;
+		MatchableTypes = matchableTypes.ToImmutableHashSet();
+		RealAppIDs = realAppIDs.ToImmutableHashSet();
+	}
+}
--- a/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/RemoteCommunication.cs
+++ b/ArchiSteamFarm.OfficialPlugins.ItemsMatcher/RemoteCommunication.cs
@ -23,6 +23,7 @@ using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 using System.Globalization;
+using System.IO;
 using System.Linq;
 using System.Net;
 using System.Net.Http;
@ -30,6 +31,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using ArchiSteamFarm.Core;
 using ArchiSteamFarm.Helpers;
+using ArchiSteamFarm.IPC.Responses;
 using ArchiSteamFarm.Localization;
 using ArchiSteamFarm.OfficialPlugins.ItemsMatcher.Data;
 using ArchiSteamFarm.Steam;
@ -54,8 +56,8 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 	private const byte MaxTradeOffersActive = 5; // The actual upper limit is 30, but we should use lower amount to allow some bots to react before we hit the maximum allowed
 	private const byte MinAnnouncementTTL = 5; // Minimum amount of minutes we must wait before the next Announcement
 	private const byte MinHeartBeatTTL = 10; // Minimum amount of minutes we must wait before sending next HeartBeat
-	private const byte MinimumSteamGuardEnabledDays = 15; // As imposed by Steam limits
 	private const byte MinimumPasswordResetCooldownDays = 5; // As imposed by Steam limits
+	private const byte MinimumSteamGuardEnabledDays = 15; // As imposed by Steam limits
 	private const byte MinPersonaStateTTL = 5; // Minimum amount of minutes we must wait before requesting persona state update

 	private static readonly ImmutableHashSet<Asset.EType> AcceptedMatchableTypes = ImmutableHashSet.Create(
@ -68,15 +70,14 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 	private readonly Bot Bot;
 	private readonly Timer? HeartBeatTimer;

-	// We access this collection only within a semaphore, therefore there is no need for concurrent access
-	private readonly Dictionary<ulong, uint> LastAnnouncedItems = new();
-
 	private readonly SemaphoreSlim MatchActivelySemaphore = new(1, 1);
 	private readonly Timer? MatchActivelyTimer;
 	private readonly SemaphoreSlim RequestsSemaphore = new(1, 1);
 	private readonly WebBrowser WebBrowser;

-	private string? LastAnnouncedTradeToken;
+	private string BotCacheFilePath => Path.Combine(SharedInfo.ConfigDirectory, $"{Bot.BotName}.{nameof(ItemsMatcher)}.cache");
+
+	private BotCache? BotCache;
 	private DateTime LastAnnouncement;
 	private DateTime LastHeartBeat;
 	private DateTime LastPersonaStateRequest;
@ -92,7 +93,7 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {

 		if (Bot.BotConfig.TradingPreferences.HasFlag(BotConfig.ETradingPreferences.SteamTradeMatcher) && Bot.BotConfig.RemoteCommunication.HasFlag(BotConfig.ERemoteCommunication.PublicListing)) {
 			HeartBeatTimer = new Timer(
-				HeartBeat,
+				OnHeartBeatTimer,
 				null,
 				TimeSpan.FromMinutes(1) + TimeSpan.FromSeconds(ASF.LoadBalancingDelay * Bot.Bots?.Count ?? 0),
 				TimeSpan.FromMinutes(1)
@ -114,12 +115,7 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 	}

 	public void Dispose() {
-		// Those are objects that are always being created if constructor doesn't throw exception
-		MatchActivelySemaphore.Dispose();
-		RequestsSemaphore.Dispose();
-		WebBrowser.Dispose();
-
-		// Those are objects that might be null and the check should be in-place
+		// Dispose timers first so we won't launch new events
 		HeartBeatTimer?.Dispose();

 		if (MatchActivelyTimer != null) {
@ -128,6 +124,25 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 				MatchActivelyTimer.Dispose();
 			}
 		}
+
+		// Ensure the semaphores are closed, then dispose the rest
+		try {
+			MatchActivelySemaphore.Wait();
+		} catch (ObjectDisposedException) {
+			// Ignored, this is fine
+		}
+
+		try {
+			RequestsSemaphore.Wait();
+		} catch (ObjectDisposedException) {
+			// Ignored, this is fine
+		}
+
+		BotCache?.Dispose();
+
+		MatchActivelySemaphore.Dispose();
+		RequestsSemaphore.Dispose();
+		WebBrowser.Dispose();
 	}

 	public async ValueTask DisposeAsync() {
@ -144,8 +159,19 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 		}

 		// Ensure the semaphores are closed, then dispose the rest
-		await MatchActivelySemaphore.WaitAsync().ConfigureAwait(false);
-		await RequestsSemaphore.WaitAsync().ConfigureAwait(false);
+		try {
+			await MatchActivelySemaphore.WaitAsync().ConfigureAwait(false);
+		} catch (ObjectDisposedException) {
+			// Ignored, this is fine
+		}
+
+		try {
+			await RequestsSemaphore.WaitAsync().ConfigureAwait(false);
+		} catch (ObjectDisposedException) {
+			// Ignored, this is fine
+		}
+
+		BotCache?.Dispose();

 		MatchActivelySemaphore.Dispose();
 		RequestsSemaphore.Dispose();
@ -250,6 +276,7 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {

 			bool matchEverything = Bot.BotConfig.TradingPreferences.HasFlag(BotConfig.ETradingPreferences.MatchEverything);

+			uint index = 0;
 			ulong previousAssetID = 0;

 			List<AssetForListing> assetsForListing = new();
@ -260,7 +287,7 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 				if (item is { AssetID: > 0, Amount: > 0, ClassID: > 0, RealAppID: > 0, Type: > Asset.EType.Unknown, Rarity: > Asset.ERarity.Unknown } && acceptedMatchableTypes.Contains(item.Type)) {
 					// Only tradable assets matter for MatchEverything bots
 					if (!matchEverything || item.Tradable) {
-						assetsForListing.Add(new AssetForListing(item, previousAssetID));
+						assetsForListing.Add(new AssetForListing(item, index, previousAssetID));
 					}

 					// But even for Fair bots, we should track and skip sets where we don't have any item to trade with
@ -277,6 +304,7 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 					}
 				}

+				index++;
 				previousAssetID = item.AssetID;
 			}

@ -301,24 +329,6 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 				}
 			}

-			if (assetsForListing.Count > MaxItemsCount) {
-				// We're not eligible, record this as a valid check
-				LastAnnouncement = DateTime.UtcNow;
-				ShouldSendAnnouncementEarlier = ShouldSendHeartBeats = false;
-
-				Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.WarningFailedWithError, $"{nameof(assetsForListing)} > {MaxItemsCount}"));
-
-				return;
-			}
-
-			if (ShouldSendHeartBeats && (tradeToken == LastAnnouncedTradeToken) && (assetsForListing.Count == LastAnnouncedItems.Count) && assetsForListing.All(item => LastAnnouncedItems.TryGetValue(item.AssetID, out uint amount) && (item.Amount == amount))) {
-				// There is nothing new to announce, this is fine, skip the request
-				LastAnnouncement = DateTime.UtcNow;
-				ShouldSendAnnouncementEarlier = false;
-
-				return;
-			}
-
 			if (!SignedInWithSteam) {
 				HttpStatusCode? signInWithSteam = await ArchiNet.SignInWithSteam(Bot, WebBrowser).ConfigureAwait(false);

@ -340,73 +350,163 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 				SignedInWithSteam = true;
 			}

-			Bot.ArchiLogger.LogGenericInfo(string.Format(CultureInfo.CurrentCulture, Localization.Strings.ListingAnnouncing, Bot.SteamID, nickname ?? Bot.SteamID.ToString(CultureInfo.InvariantCulture), assetsForListing.Count));
+			BotCache ??= await BotCache.CreateOrLoad(BotCacheFilePath).ConfigureAwait(false);

-			BasicResponse? response = await Backend.AnnounceForListing(Bot.SteamID, WebBrowser, assetsForListing, acceptedMatchableTypes, (uint) inventory.Count, matchEverything, tradeToken, nickname, avatarHash).ConfigureAwait(false);
+			if (!matchEverything) {
+				// We should deduplicate our sets before sending them to the server, for doing that we'll use ASFB set parts data
+				HashSet<uint> realAppIDs = new();
+				Dictionary<(uint RealAppID, Asset.EType Type, Asset.ERarity Rarity), Dictionary<ulong, uint>> state = new();

-			if (response == null) {
-				// This is actually a network failure, so we'll stop sending heartbeats but not record it as valid check
-				ShouldSendHeartBeats = false;
+				foreach (AssetForListing asset in assetsForListing) {
+					realAppIDs.Add(asset.RealAppID);

-				Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.ErrorObjectIsNull, nameof(response)));
+					(uint RealAppID, Asset.EType Type, Asset.ERarity Rarity) key = (asset.RealAppID, asset.Type, asset.Rarity);

-				return;
-			}
+					if (state.TryGetValue(key, out Dictionary<ulong, uint>? set)) {
+						set[asset.ClassID] = set.TryGetValue(asset.ClassID, out uint amount) ? amount + asset.Amount : asset.Amount;
+					} else {
+						state[key] = new Dictionary<ulong, uint> { { asset.ClassID, asset.Amount } };
+					}
+				}

-			if (response.StatusCode.IsRedirectionCode()) {
-				ShouldSendHeartBeats = false;
-
-				Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.WarningFailedWithError, response.StatusCode));
-
-				if (response.FinalUri.Host != ArchiWebHandler.SteamCommunityURL.Host) {
-					ASF.ArchiLogger.LogGenericError(string.Format(CultureInfo.CurrentCulture, Strings.WarningUnknownValuePleaseReport, nameof(response.FinalUri), response.FinalUri));
+				ObjectResponse<GenericResponse<ImmutableHashSet<SetPart>>>? setPartsResponse = await Backend.GetSetParts(WebBrowser, Bot.SteamID, acceptedMatchableTypes, realAppIDs).ConfigureAwait(false);

+				if (!HandleAnnounceResponse(BotCache, tradeToken, response: setPartsResponse) || (setPartsResponse?.Content?.Result == null)) {
 					return;
 				}

-				// We've expected the result, not the redirection to the sign in, we need to authenticate again
-				SignedInWithSteam = false;
+				Dictionary<(uint RealAppID, Asset.EType Type, Asset.ERarity Rarity), HashSet<ulong>> databaseSets = setPartsResponse.Content.Result.GroupBy(static setPart => (setPart.RealAppID, setPart.Type, setPart.Rarity)).ToDictionary(static group => group.Key, static group => group.Select(static setPart => setPart.ClassID).ToHashSet());
+
+				HashSet<(ulong ClassID, uint Amount)> setCopy = new();
+
+				foreach (((uint RealAppID, Asset.EType Type, Asset.ERarity Rarity) key, Dictionary<ulong, uint> set) in state) {
+					if (!databaseSets.TryGetValue(key, out HashSet<ulong>? databaseSet)) {
+						// We have no clue about this set, we can't do any optimization
+						continue;
+					}
+
+					if ((databaseSet.Count != set.Count) || !databaseSet.SetEquals(set.Keys)) {
+						// User either has more or less classIDs than we know about, we can't optimize this
+						continue;
+					}
+
+					// User has all classIDs we know about, we can deduplicate his items based on lowest count
+					setCopy.Clear();
+
+					uint minimumAmount = uint.MaxValue;
+
+					foreach ((ulong classID, uint amount) in set) {
+						if (amount < minimumAmount) {
+							minimumAmount = amount;
+						}
+
+						setCopy.Add((classID, amount));
+					}
+
+					foreach ((ulong classID, uint amount) in setCopy) {
+						if (minimumAmount >= amount) {
+							set.Remove(classID);
+
+							continue;
+						}
+
+						set[classID] = amount - minimumAmount;
+					}
+				}
+
+				HashSet<AssetForListing> assetsForListingFiltered = new();
+
+				foreach (AssetForListing asset in assetsForListing.Where(asset => state.TryGetValue((asset.RealAppID, asset.Type, asset.Rarity), out Dictionary<ulong, uint>? setState) && setState.TryGetValue(asset.ClassID, out uint targetAmount) && (targetAmount > 0)).OrderByDescending(static asset => asset.Tradable).ThenByDescending(static asset => asset.Index)) {
+					(uint RealAppID, Asset.EType Type, Asset.ERarity Rarity) key = (asset.RealAppID, asset.Type, asset.Rarity);
+
+					if (!state.TryGetValue(key, out Dictionary<ulong, uint>? setState) || !setState.TryGetValue(asset.ClassID, out uint targetAmount) || (targetAmount == 0)) {
+						// We're not interested in this combination
+						continue;
+					}
+
+					if (asset.Amount >= targetAmount) {
+						asset.Amount = targetAmount;
+
+						if (setState.Remove(asset.ClassID) && (setState.Count == 0)) {
+							state.Remove(key);
+						}
+					} else {
+						setState[asset.ClassID] = targetAmount - asset.Amount;
+					}
+
+					assetsForListingFiltered.Add(asset);
+				}
+
+				assetsForListing = assetsForListingFiltered.OrderBy(static asset => asset.Index).ToList();
+
+				if (assetsForListing.Count == 0) {
+					// We're not eligible, record this as a valid check
+					LastAnnouncement = DateTime.UtcNow;
+					ShouldSendAnnouncementEarlier = ShouldSendHeartBeats = false;
+
+					return;
+				}
+			}
+
+			if (assetsForListing.Count > MaxItemsCount) {
+				// We're not eligible, record this as a valid check
+				LastAnnouncement = DateTime.UtcNow;
+				ShouldSendAnnouncementEarlier = ShouldSendHeartBeats = false;
+
+				Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.WarningFailedWithError, $"{nameof(assetsForListing)} > {MaxItemsCount}"));

 				return;
 			}

-			if (response.StatusCode.IsClientErrorCode()) {
-				// ArchiNet told us that we've sent a bad request, so the process should restart from the beginning at later time
-				ShouldSendHeartBeats = false;
+			string checksum = Backend.GenerateChecksumFor(assetsForListing);
+			string? previousChecksum = BotCache.LastAnnouncedAssetsForListing.Count > 0 ? Backend.GenerateChecksumFor(BotCache.LastAnnouncedAssetsForListing) : null;

-				Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.WarningFailedWithError, response.StatusCode));
+			if ((tradeToken == BotCache.LastAnnouncedTradeToken) && (checksum == previousChecksum)) {
+				// We've determined our state to be the same, we can skip announce entirely and start sending heartbeats exclusively
+				LastAnnouncement = DateTime.UtcNow;
+				ShouldSendAnnouncementEarlier = false;
+				ShouldSendHeartBeats = true;

-				switch (response.StatusCode) {
-					case HttpStatusCode.Forbidden:
-						// ArchiNet told us to stop submitting data for now
-						LastAnnouncement = DateTime.UtcNow.AddYears(1);
+				Utilities.InBackground(() => OnHeartBeatTimer());

-						return;
-					case HttpStatusCode.TooManyRequests:
-						// ArchiNet told us to try again later
-						LastAnnouncement = DateTime.UtcNow.AddDays(1);
+				return;
+			}

-						return;
-					default:
-						// There is something wrong with our payload or the server, we shouldn't retry for at least several hours
-						LastAnnouncement = DateTime.UtcNow.AddHours(6);
+			if (BotCache.LastAnnouncedAssetsForListing.Count > 0) {
+				Dictionary<ulong, AssetForListing> previousInventoryState = BotCache.LastAnnouncedAssetsForListing.ToDictionary(static asset => asset.AssetID);

-						return;
+				HashSet<AssetForListing> inventoryAdded = new();
+				HashSet<AssetForListing> inventoryRemoved = new();
+
+				foreach (AssetForListing asset in assetsForListing) {
+					if (previousInventoryState.Remove(asset.AssetID, out AssetForListing? previousAsset) && (asset.BackendHashCode == previousAsset.BackendHashCode)) {
+						continue;
+					}
+
+					inventoryAdded.Add(asset);
+				}
+
+				foreach (AssetForListing asset in previousInventoryState.Values) {
+					inventoryRemoved.Add(asset);
+				}
+
+				Bot.ArchiLogger.LogGenericInfo(string.Format(CultureInfo.CurrentCulture, Localization.Strings.ListingAnnouncing, Bot.SteamID, nickname ?? Bot.SteamID.ToString(CultureInfo.InvariantCulture), assetsForListing.Count));
+
+				BasicResponse? diffResponse = await Backend.AnnounceDiffForListing(WebBrowser, Bot.SteamID, inventoryAdded, checksum, acceptedMatchableTypes, (uint) inventory.Count, matchEverything, tradeToken, inventoryRemoved, previousChecksum, nickname, avatarHash).ConfigureAwait(false);
+
+				if (HandleAnnounceResponse(BotCache, tradeToken, previousChecksum, assetsForListing, diffResponse)) {
+					// Our diff announce has succeeded, we have nothing to do further
+					Bot.ArchiLogger.LogGenericInfo(Strings.Success);
+
+					return;
 				}
 			}

-			LastAnnouncement = LastHeartBeat = DateTime.UtcNow;
-			ShouldSendAnnouncementEarlier = false;
-			ShouldSendHeartBeats = true;
+			Bot.ArchiLogger.LogGenericInfo(string.Format(CultureInfo.CurrentCulture, Localization.Strings.ListingAnnouncing, Bot.SteamID, nickname ?? Bot.SteamID.ToString(CultureInfo.InvariantCulture), assetsForListing.Count));

-			LastAnnouncedTradeToken = tradeToken;
-			LastAnnouncedItems.Clear();
+			BasicResponse? response = await Backend.AnnounceForListing(WebBrowser, Bot.SteamID, assetsForListing, checksum, acceptedMatchableTypes, (uint) inventory.Count, matchEverything, tradeToken, nickname, avatarHash).ConfigureAwait(false);

-			foreach (AssetForListing item in assetsForListing) {
-				LastAnnouncedItems[item.AssetID] = item.Amount;
-			}
-
-			LastAnnouncedItems.TrimExcess();
+			HandleAnnounceResponse(BotCache, tradeToken, assetsForListing: assetsForListing, response: response);
 		} finally {
 			RequestsSemaphore.Release();
 		}
@ -425,62 +525,74 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {
 		}
 	}

-	private async void HeartBeat(object? state = null) {
-		if (!Bot.IsConnectedAndLoggedOn || (Bot.HeartBeatFailures > 0)) {
-			return;
+	private bool HandleAnnounceResponse(BotCache botCache, string tradeToken, string? previousInventoryChecksum = null, ICollection<AssetForListing>? assetsForListing = null, BasicResponse? response = null) {
+		ArgumentNullException.ThrowIfNull(botCache);
+		ArgumentException.ThrowIfNullOrEmpty(tradeToken);
+
+		if (response == null) {
+			// This is actually a network failure, so we'll stop sending heartbeats but not record it as valid check
+			ShouldSendHeartBeats = false;
+
+			Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.ErrorObjectIsNull, nameof(response)));
+
+			return false;
 		}

-		// Request persona update if needed
-		if ((DateTime.UtcNow > LastPersonaStateRequest.AddMinutes(MinPersonaStateTTL)) && (DateTime.UtcNow > LastAnnouncement.AddMinutes(ShouldSendAnnouncementEarlier ? MinAnnouncementTTL : MaxAnnouncementTTL))) {
-			LastPersonaStateRequest = DateTime.UtcNow;
-			Bot.RequestPersonaStateUpdate();
-		}
+		if (response.StatusCode.IsRedirectionCode()) {
+			ShouldSendHeartBeats = false;

-		if (!ShouldSendHeartBeats || (DateTime.UtcNow < LastHeartBeat.AddMinutes(MinHeartBeatTTL))) {
-			return;
-		}
+			Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.WarningFailedWithError, response.StatusCode));

-		if (!await RequestsSemaphore.WaitAsync(0).ConfigureAwait(false)) {
-			return;
-		}
+			if (response.FinalUri.Host != ArchiWebHandler.SteamCommunityURL.Host) {
+				ASF.ArchiLogger.LogGenericError(string.Format(CultureInfo.CurrentCulture, Strings.WarningUnknownValuePleaseReport, nameof(response.FinalUri), response.FinalUri));

-		try {
-			BasicResponse? response = await Backend.HeartBeatForListing(Bot, WebBrowser).ConfigureAwait(false);
-
-			if (response == null) {
-				// This is actually a network failure, we should keep sending heartbeats for now
-				return;
+				return false;
 			}

-			if (response.StatusCode.IsRedirectionCode()) {
-				ShouldSendHeartBeats = false;
+			// We've expected the result, not the redirection to the sign in, we need to authenticate again
+			SignedInWithSteam = false;

-				Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.WarningFailedWithError, response.StatusCode));
-
-				if (response.FinalUri.Host != ArchiWebHandler.SteamCommunityURL.Host) {
-					ASF.ArchiLogger.LogGenericError(string.Format(CultureInfo.CurrentCulture, Strings.WarningUnknownValuePleaseReport, nameof(response.FinalUri), response.FinalUri));
-
-					return;
-				}
-
-				// We've expected the result, not the redirection to the sign in, we need to authenticate again
-				SignedInWithSteam = false;
-
-				return;
-			}
-
-			if (response.StatusCode.IsClientErrorCode()) {
-				ShouldSendHeartBeats = false;
-
-				Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.WarningFailedWithError, response.StatusCode));
-
-				return;
-			}
-
-			LastHeartBeat = DateTime.UtcNow;
-		} finally {
-			RequestsSemaphore.Release();
+			return false;
 		}
+
+		if (response.StatusCode.IsClientErrorCode()) {
+			// ArchiNet told us that we've sent a bad request, so the process should restart from the beginning at later time
+			ShouldSendHeartBeats = false;
+
+			Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.WarningFailedWithError, response.StatusCode));
+
+			switch (response.StatusCode) {
+				case HttpStatusCode.Conflict when !string.IsNullOrEmpty(previousInventoryChecksum):
+					// ArchiNet told us to do full announcement instead
+					return false;
+				case HttpStatusCode.Forbidden:
+					// ArchiNet told us to stop submitting data for now
+					LastAnnouncement = DateTime.UtcNow.AddYears(1);
+
+					return false;
+				case HttpStatusCode.TooManyRequests:
+					// ArchiNet told us to try again later
+					LastAnnouncement = DateTime.UtcNow.AddDays(1);
+
+					return false;
+				default:
+					// There is something wrong with our payload or the server, we shouldn't retry for at least several hours
+					LastAnnouncement = DateTime.UtcNow.AddHours(6);
+
+					return false;
+			}
+		}
+
+		if (assetsForListing?.Count > 0) {
+			LastAnnouncement = LastHeartBeat = DateTime.UtcNow;
+			ShouldSendAnnouncementEarlier = false;
+			ShouldSendHeartBeats = true;
+
+			botCache.LastAnnouncedAssetsForListing.ReplaceWith(assetsForListing);
+			botCache.LastAnnouncedTradeToken = tradeToken;
+		}
+
+		return true;
 	}

 	private async Task<bool?> IsEligibleForListing() {
@ -1089,4 +1201,83 @@ internal sealed class RemoteCommunication : IAsyncDisposable, IDisposable {

 		return matchedSets > 0;
 	}
+
+	private async void OnHeartBeatTimer(object? state = null) {
+		if (!Bot.IsConnectedAndLoggedOn || (Bot.HeartBeatFailures > 0)) {
+			return;
+		}
+
+		// Request persona update if needed
+		if ((DateTime.UtcNow > LastPersonaStateRequest.AddMinutes(MinPersonaStateTTL)) && (DateTime.UtcNow > LastAnnouncement.AddMinutes(ShouldSendAnnouncementEarlier ? MinAnnouncementTTL : MaxAnnouncementTTL))) {
+			LastPersonaStateRequest = DateTime.UtcNow;
+			Bot.RequestPersonaStateUpdate();
+		}
+
+		if (!ShouldSendHeartBeats || (DateTime.UtcNow < LastHeartBeat.AddMinutes(MinHeartBeatTTL))) {
+			return;
+		}
+
+		if (!await RequestsSemaphore.WaitAsync(0).ConfigureAwait(false)) {
+			return;
+		}
+
+		try {
+			if (!SignedInWithSteam) {
+				HttpStatusCode? signInWithSteam = await ArchiNet.SignInWithSteam(Bot, WebBrowser).ConfigureAwait(false);
+
+				if (signInWithSteam == null) {
+					// This is actually a network failure, so we'll stop sending heartbeats but not record it as valid check
+					ShouldSendHeartBeats = false;
+
+					return;
+				}
+
+				if (!signInWithSteam.Value.IsSuccessCode()) {
+					// SignIn procedure failed and it wasn't a network error, hold off with future tries at least for a full day
+					LastAnnouncement = DateTime.UtcNow.AddDays(1);
+					ShouldSendHeartBeats = false;
+
+					return;
+				}
+
+				SignedInWithSteam = true;
+			}
+
+			BasicResponse? response = await Backend.HeartBeatForListing(Bot, WebBrowser).ConfigureAwait(false);
+
+			if (response == null) {
+				// This is actually a network failure, we should keep sending heartbeats for now
+				return;
+			}
+
+			if (response.StatusCode.IsRedirectionCode()) {
+				ShouldSendHeartBeats = false;
+
+				Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.WarningFailedWithError, response.StatusCode));
+
+				if (response.FinalUri.Host != ArchiWebHandler.SteamCommunityURL.Host) {
+					ASF.ArchiLogger.LogGenericError(string.Format(CultureInfo.CurrentCulture, Strings.WarningUnknownValuePleaseReport, nameof(response.FinalUri), response.FinalUri));
+
+					return;
+				}
+
+				// We've expected the result, not the redirection to the sign in, we need to authenticate again
+				SignedInWithSteam = false;
+
+				return;
+			}
+
+			if (response.StatusCode.IsClientErrorCode()) {
+				ShouldSendHeartBeats = false;
+
+				Bot.ArchiLogger.LogGenericWarning(string.Format(CultureInfo.CurrentCulture, Strings.WarningFailedWithError, response.StatusCode));
+
+				return;
+			}
+
+			LastHeartBeat = DateTime.UtcNow;
+		} finally {
+			RequestsSemaphore.Release();
+		}
+	}
 }
--- a/ArchiSteamFarm/Collections/ConcurrentHashSet.cs
+++ b/ArchiSteamFarm/Collections/ConcurrentHashSet.cs
@ -29,6 +29,7 @@ using JetBrains.Annotations;
 namespace ArchiSteamFarm.Collections;

 public sealed class ConcurrentHashSet<T> : IReadOnlyCollection<T>, ISet<T> where T : notnull {
+	[PublicAPI]
 	public event EventHandler? OnModified;

 	public int Count => BackingCollection.Count;
--- a/ArchiSteamFarm/Collections/ConcurrentList.cs
+++ b/ArchiSteamFarm/Collections/ConcurrentList.cs
@ -19,13 +19,18 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.

+using System;
 using System.Collections;
 using System.Collections.Generic;
+using JetBrains.Annotations;
 using Nito.AsyncEx;

 namespace ArchiSteamFarm.Collections;

 internal sealed class ConcurrentList<T> : IList<T>, IReadOnlyList<T> {
+	[PublicAPI]
+	public event EventHandler? OnModified;
+
 	public bool IsReadOnly => false;

 	internal int Count {
@ -53,6 +58,8 @@ internal sealed class ConcurrentList<T> : IList<T>, IReadOnlyList<T> {
 			using (Lock.WriterLock()) {
 				BackingCollection[index] = value;
 			}
+
+			OnModified?.Invoke(this, EventArgs.Empty);
 		}
 	}

@ -60,12 +67,16 @@ internal sealed class ConcurrentList<T> : IList<T>, IReadOnlyList<T> {
 		using (Lock.WriterLock()) {
 			BackingCollection.Add(item);
 		}
+
+		OnModified?.Invoke(this, EventArgs.Empty);
 	}

 	public void Clear() {
 		using (Lock.WriterLock()) {
 			BackingCollection.Clear();
 		}
+
+		OnModified?.Invoke(this, EventArgs.Empty);
 	}

 	public bool Contains(T item) {
@ -92,18 +103,28 @@ internal sealed class ConcurrentList<T> : IList<T>, IReadOnlyList<T> {
 		using (Lock.WriterLock()) {
 			BackingCollection.Insert(index, item);
 		}
+
+		OnModified?.Invoke(this, EventArgs.Empty);
 	}

 	public bool Remove(T item) {
 		using (Lock.WriterLock()) {
-			return BackingCollection.Remove(item);
+			if (!BackingCollection.Remove(item)) {
+				return false;
+			}
 		}
+
+		OnModified?.Invoke(this, EventArgs.Empty);
+
+		return true;
 	}

 	public void RemoveAt(int index) {
 		using (Lock.WriterLock()) {
 			BackingCollection.RemoveAt(index);
 		}
+
+		OnModified?.Invoke(this, EventArgs.Empty);
 	}

 	IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
@ -113,5 +134,7 @@ internal sealed class ConcurrentList<T> : IList<T>, IReadOnlyList<T> {
 			BackingCollection.Clear();
 			BackingCollection.AddRange(collection);
 		}
+
+		OnModified?.Invoke(this, EventArgs.Empty);
 	}
 }
--- a/ArchiSteamFarm/Core/ASF.cs
+++ b/ArchiSteamFarm/Core/ASF.cs
@ -30,7 +30,6 @@ using System.IO;
 using System.IO.Compression;
 using System.Linq;
 using System.Reflection;
-using System.Security.Cryptography;
 using System.Threading;
 using System.Threading.Tasks;
 using ArchiSteamFarm.Helpers;
@ -323,7 +322,7 @@ public static class ASF {

 			byte[] responseBytes = response.Content as byte[] ?? response.Content.ToArray();

-			string checksum = Convert.ToHexString(SHA512.HashData(responseBytes));
+			string checksum = Utilities.GenerateChecksumFor(responseBytes);

 			if (!checksum.Equals(remoteChecksum, StringComparison.OrdinalIgnoreCase)) {
 				ArchiLogger.LogGenericError(Strings.ChecksumWrong);
--- a/ArchiSteamFarm/Core/Utilities.cs
+++ b/ArchiSteamFarm/Core/Utilities.cs
@ -29,6 +29,7 @@ using System.IO;
 using System.Linq;
 using System.Net;
 using System.Resources;
+using System.Security.Cryptography;
 using System.Threading;
 using System.Threading.Tasks;
 using AngleSharp.Dom;
@ -51,6 +52,15 @@ public static class Utilities {

 	private static readonly JwtSecurityTokenHandler JwtSecurityTokenHandler = new();

+	[PublicAPI]
+	public static string GenerateChecksumFor(byte[] source) {
+		ArgumentNullException.ThrowIfNull(source);
+
+		byte[] hash = SHA512.HashData(source);
+
+		return Convert.ToHexString(hash);
+	}
+
 	[PublicAPI]
 	public static string GetArgsAsText(string[] args, byte argsToSkip, string delimiter) {
 		ArgumentNullException.ThrowIfNull(args);
@ -321,7 +331,7 @@ public static class Utilities {
 			}
 		}

-		return (result.Score < 4, suggestions is { Count: > 0 } ? string.Join(" ", suggestions.Where(static suggestion => suggestion.Length > 0)) : null);
+		return (result.Score < 4, suggestions is { Count: > 0 } ? string.Join(' ', suggestions.Where(static suggestion => suggestion.Length > 0)) : null);
 	}

 	internal static void WarnAboutIncompleteTranslation(ResourceManager resourceManager) {
--- a/ArchiSteamFarm/IPC/WebUtilities.cs
+++ b/ArchiSteamFarm/IPC/WebUtilities.cs
@ -34,7 +34,7 @@ internal static class WebUtilities {
 	internal static string? GetUnifiedName(this Type type) {
 		ArgumentNullException.ThrowIfNull(type);

-		return type.GenericTypeArguments.Length == 0 ? type.FullName : $"{type.Namespace}.{type.Name}{string.Join("", type.GenericTypeArguments.Select(static innerType => $"[{innerType.GetUnifiedName()}]"))}";
+		return type.GenericTypeArguments.Length == 0 ? type.FullName : $"{type.Namespace}.{type.Name}{string.Join(null, type.GenericTypeArguments.Select(static innerType => $"[{innerType.GetUnifiedName()}]"))}";
 	}

 	[UnconditionalSuppressMessage("AssemblyLoadTrimming", "IL2057:TypeGetType", Justification = "We don't care about trimmed assemblies, as we need it to work only with the known (used) ones")]
--- a/ArchiSteamFarm/Program.cs
+++ b/ArchiSteamFarm/Program.cs
@ -86,7 +86,7 @@ internal static class Program {
 		IEnumerable<string> arguments = Environment.GetCommandLineArgs().Skip(executableName.Equals(SharedInfo.AssemblyName, StringComparison.Ordinal) ? 1 : 0);

 		try {
-			Process.Start(OS.ProcessFileName, string.Join(" ", arguments));
+			Process.Start(OS.ProcessFileName, string.Join(' ', arguments));
 		} catch (Exception e) {
 			ASF.ArchiLogger.LogGenericException(e);
 		}
--- a/ArchiSteamFarm/Web/WebBrowser.cs
+++ b/ArchiSteamFarm/Web/WebBrowser.cs
@ -753,7 +753,7 @@ public sealed class WebBrowser : IDisposable {
 							try {
 								requestMessage.Content = new FormUrlEncodedContent(nameValueCollection);
 							} catch (UriFormatException) {
-								requestMessage.Content = new StringContent(string.Join("&", nameValueCollection.Select(static kv => $"{Uri.EscapeDataString(kv.Key)}={Uri.EscapeDataString(kv.Value)}")), null, "application/x-www-form-urlencoded");
+								requestMessage.Content = new StringContent(string.Join('&', nameValueCollection.Select(static kv => $"{Uri.EscapeDataString(kv.Key)}={Uri.EscapeDataString(kv.Value)}")), null, "application/x-www-form-urlencoded");
 							}

 							break;