JustArchiNET/ArchiSteamFarm · error · NotSupportedException

steamID is null!

Error message

steamID is null!

What it means

When GetInventoryAsync is called with an explicit non-zero steamID, ASF validates that the ID represents an individual Steam account (SteamID.IsIndividualAccount). A clan/group/anon/invalid ID raises a NotSupportedException ('steamID is null!'). This is an input-validation guard before any network call.

Source

Thrown at ArchiSteamFarm/Steam/Integration/ArchiWebHandler.cs:306

		ArgumentOutOfRangeException.ThrowIfZero(contextID);
		ArgumentOutOfRangeException.ThrowIfZero(itemsCountPerRequest);

		if (steamID == 0) {
			if (!Initialized) {
				byte connectionTimeout = ASF.GlobalConfig?.ConnectionTimeout ?? GlobalConfig.DefaultConnectionTimeout;

				for (byte i = 0; (i < connectionTimeout) && !Initialized && Bot.IsConnectedAndLoggedOn; i++) {
					await Task.Delay(1000).ConfigureAwait(false);
				}

				if (!Initialized) {
					throw new HttpRequestException(Strings.WarningFailed);
				}
			}

			steamID = Bot.SteamID;
		} else if (!new SteamID(steamID).IsIndividualAccount) {
			throw new NotSupportedException(Strings.FormatErrorObjectIsNull(nameof(steamID)));
		}

		if (ASF.InventorySemaphore == null) {
			throw new InvalidOperationException(nameof(ASF.InventorySemaphore));
		}

		if (string.IsNullOrEmpty(language)) {
			language = "english";
		}

		ulong startAssetID = 0;

		// We need to store asset IDs to make sure we won't get duplicate items
		HashSet<ulong>? assetIDs = null;

		Dictionary<(ulong ClassID, ulong InstanceID), InventoryDescription>? descriptions = null;

		int rateLimitingDelay = (ASF.GlobalConfig?.InventoryLimiterDelay ?? GlobalConfig.DefaultInventoryLimiterDelay) * 1000;

View on GitHub (pinned to fe57c4129f)

Solutions

1. Pass only individual-account SteamID64 values (verify on steamid.io that type is 'Individual').
2. Validate steamID via SteamKit2 SteamID.IsIndividualAccount before calling.
3. To fetch the bot's own inventory, call with steamID: 0 rather than a group ID.
4. Sanitize ID inputs from user/external sources before use.

Example fix

// before
var inv = bot.ArchiWebHandler.GetInventoryAsync(steamID: groupSteamID);
// after
var sid = new SteamKit2.SteamID(groupSteamID);
if (!sid.IsIndividualAccount) return;
var inv = bot.ArchiWebHandler.GetInventoryAsync(steamID: sid.ConvertToUInt64());

var sid = new SteamKit2.SteamID(steamID);
if (steamID == 0 || !sid.IsIndividualAccount)
    throw new ArgumentException("steamID must be an individual account", nameof(steamID));

static bool IsValidTargetSteamID(ulong steamID) =>
    steamID != 0 && new SteamKit2.SteamID(steamID).IsIndividualAccount;

try { await foreach (var a in webHandler.GetInventoryAsync(steamID)) { /* ... */ } }
catch (NotSupportedException ex) when (ex.Message.Contains("steamID")) {
    // reject the supplied ID upstream
}

When it happens

Trigger: Passing a SteamID64 that is a group/clan account, an anonymous ID, a console ID, or otherwise not a type-1 individual account to GetInventoryAsync.

Common situations: Passing a group's SteamID instead of a user's; using an ID parsed from the wrong source (e.g. a clan chat ID); malformed/zero-padded ID after string manipulation.

Related errors

• SteamID is invalid!
• Received unknown value for {0}, please report this: {1}
• Failed due to error: Client.IsConnected
• Failed due to error: {0}
• response is null!

AI-assisted analysis of JustArchiNET/ArchiSteamFarm@fe57c4129f (2026-08-13). Data as JSON: /api/errors/bf092a5c2136cfd0. Report an issue: GitHub.