Class SteamNetworkClient

Namespace

SteamNetworkLib

Assembly

SteamNetworkLib.dll

Main entry point for SteamNetworkLib - provides simplified access to all Steam networking features. Perfect for use in MelonLoader mods that need Steam lobby and P2P functionality.

public class SteamNetworkClient : IDisposable

Inheritance

object

SteamNetworkClient

Implements

IDisposable

Inherited Members

object.GetType()

object.MemberwiseClone()

object.ToString()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Constructors

SteamNetworkClient()

Initializes a new instance of the SteamNetworkClient class. Call Initialize() before using any other methods.

public SteamNetworkClient()

Properties

CurrentLobby

Gets information about the current lobby, or null if not in a lobby.

public LobbyInfo? CurrentLobby { get; }

Property Value

LobbyInfo

IsHost

Gets whether the local player is the host of the current lobby.

public bool IsHost { get; }

Property Value

bool

IsInLobby

Gets whether the local player is currently in a lobby.

public bool IsInLobby { get; }

Property Value

bool

LibraryVersion

Gets the current version of SteamNetworkLib.

public static string LibraryVersion { get; }

Property Value

string

LobbyData

Gets the lobby data manager for handling lobby-wide data.

public SteamLobbyData LobbyData { get; }

Property Value

SteamLobbyData

LobbyManager

Gets the lobby manager for handling Steam lobby operations.

public SteamLobbyManager LobbyManager { get; }

Property Value

SteamLobbyManager

LocalPlayerId

Gets the Steam ID of the local player.

public CSteamID LocalPlayerId { get; }

Property Value

CSteamID

MemberData

Gets the member data manager for handling player-specific data.

public SteamMemberData MemberData { get; }

Property Value

SteamMemberData

P2PManager

Gets the P2P manager for handling peer-to-peer communication.

public SteamP2PManager P2PManager { get; }

Property Value

SteamP2PManager

VersionCheckEnabled

Gets or sets whether automatic version checking is enabled. When enabled, the library will automatically check for version compatibility between players.

public bool VersionCheckEnabled { get; set; }

Property Value

bool

Remarks

IMPORTANT: Version checking is crucial for ensuring proper data transfer and synchronization between players.

Disabling this feature or ignoring version mismatches may result in:

• Data serialization/deserialization failures
• Message format incompatibilities
• Synchronization errors
• Unexpected networking behavior or crashes

It is strongly recommended to keep this enabled and ensure all players use the same SteamNetworkLib version.

Methods

BroadcastMessage(P2PMessage)

Sends a message to all players in the lobby. This is a non-async wrapper around BroadcastMessageAsync.

public void BroadcastMessage(P2PMessage message)

Parameters

message P2PMessage

The message to broadcast.

Remarks

This method is provided for backward compatibility. For new code, use BroadcastMessageAsync instead.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

P2PException

Thrown when the message cannot be sent.

BroadcastMessageAsync(P2PMessage)

Sends a message to all players in the lobby.

public Task BroadcastMessageAsync(P2PMessage message)

Parameters

message P2PMessage

The message to broadcast.

Returns

Task

Remarks

This method sends the message to each player individually.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

P2PException

Thrown when the message cannot be sent.

BroadcastTextMessage(string)

Broadcasts a simple text message to all players. This is a non-async wrapper around BroadcastTextMessageAsync.

public void BroadcastTextMessage(string text)

Parameters

text string

The text message to broadcast.

Remarks

This method is provided for backward compatibility. For new code, use BroadcastTextMessageAsync instead.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

P2PException

Thrown when the message cannot be sent.

BroadcastTextMessageAsync(string)

Broadcasts a simple text message to all players.

public Task BroadcastTextMessageAsync(string text)

Parameters

text string

The text message to broadcast.

Returns

Task

A task that represents the asynchronous operation.

Remarks

This is a convenience method that creates a TextMessage internally.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

P2PException

Thrown when the message cannot be sent.

CheckLibraryVersionCompatibility()

Performs a comprehensive version check and fires the OnVersionMismatch event if incompatibilities are found.

public bool CheckLibraryVersionCompatibility()

Returns

bool

True if all versions are compatible, false if mismatches were detected.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby.

CreateLobbyAsync(ELobbyType, int)

Creates a new lobby with the specified settings.

public Task<LobbyInfo> CreateLobbyAsync(ELobbyType lobbyType = 1, int maxMembers = 4)

Parameters

lobbyType ELobbyType

The type of lobby to create.

maxMembers int

The maximum number of members allowed in the lobby.

Returns

Task<LobbyInfo>

A task that represents the asynchronous operation. The task result contains the lobby information.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when lobby creation fails.

Dispose()

Releases all resources used by the SteamNetworkClient.

public void Dispose()

Remarks

This method disposes all component managers and releases any unmanaged resources.

GetDataForAllPlayers(string)

Gets the same data key for all players in the lobby.

public Dictionary<CSteamID, string> GetDataForAllPlayers(string key)

Parameters

key string

The data key.

Returns

Dictionary<CSteamID, string>

A dictionary mapping player Steam IDs to their data values.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby.

GetLobbyData(string)

Gets lobby-wide data.

public string? GetLobbyData(string key)

Parameters

key string

The data key.

Returns

string

The data value, or null if not found.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby.

GetLobbyMembers()

Gets all members in the current lobby.

public List<MemberInfo> GetLobbyMembers()

Returns

List<MemberInfo>

A list of MemberInfo objects for all players in the lobby.

Remarks

Returns an empty list if not currently in a lobby.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

GetMyData(string)

Gets data for the local player.

public string? GetMyData(string key)

Parameters

key string

The data key.

Returns

string

The data value, or null if not found.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby.

GetPlayerData(CSteamID, string)

Gets data for a specific player.

public string? GetPlayerData(CSteamID playerId, string key)

Parameters

playerId CSteamID

The Steam ID of the player.

key string

The data key.

Returns

string

The data value, or null if not found.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby or the player is not in the lobby.

GetPlayerLibraryVersions()

Gets the SteamNetworkLib versions of all players in the lobby.

public Dictionary<CSteamID, string> GetPlayerLibraryVersions()

Returns

Dictionary<CSteamID, string>

A dictionary mapping player Steam IDs to their SteamNetworkLib versions. Players without version data are excluded.

Remarks

Use this method to identify which players have different library versions that could cause data transfer issues.

Players with missing version data may be using older versions of SteamNetworkLib that don't support version checking,

which could result in unpredictable networking behavior and synchronization failures.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby.

Initialize()

Initializes the Steam networking client. Must be called before using any other methods.

public bool Initialize()

Returns

bool

True if initialization was successful.

Exceptions

SteamNetworkException

Thrown when Steam is not available or when initialization fails.

InviteFriend(CSteamID)

Invites a friend to the current lobby.

public void InviteFriend(CSteamID friendId)

Parameters

friendId CSteamID

The Steam ID of the friend to invite.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby or invitation fails.

IsModDataCompatible(string)

Checks if all players have compatible mod data for a given key.

public bool IsModDataCompatible(string dataKey)

Parameters

dataKey string

The data key to check for compatibility.

Returns

bool

True if all players have the same data value, false otherwise.

Remarks

This method is useful for verifying that all players are using the same mod version.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby.

JoinLobbyAsync(CSteamID)

Joins an existing lobby by ID.

public Task<LobbyInfo> JoinLobbyAsync(CSteamID lobbyId)

Parameters

lobbyId CSteamID

The Steam ID of the lobby to join.

Returns

Task<LobbyInfo>

A task that represents the asynchronous operation. The task result contains the lobby information.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when joining the lobby fails.

LeaveLobby()

Leaves the current lobby.

public void LeaveLobby()

Remarks

This method has no effect if the local player is not currently in a lobby.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

OpenInviteDialog()

Opens the Steam overlay invite dialog.

public void OpenInviteDialog()

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby or the overlay fails to open.

ProcessIncomingMessages()

Processes incoming P2P packets. Call this regularly (e.g., in Update()).

public void ProcessIncomingMessages()

Remarks

This method should be called frequently to ensure timely processing of incoming messages. If not called regularly, messages may be delayed or dropped.

RegisterMessageHandler<T>(Action<T, CSteamID>)

Registers a handler for a specific message type.

public void RegisterMessageHandler<T>(Action<T, CSteamID> handler) where T : P2PMessage, new()

Parameters

handler Action<T, CSteamID>

The handler function that will be called when messages of this type are received.

Type Parameters

T

The type of message to handle.

Remarks

The handler will be called with the message and the sender's Steam ID.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

SendDataSyncAsync(CSteamID, string, string, string)

Sends a data synchronization message to a player.

public Task<bool> SendDataSyncAsync(CSteamID playerId, string key, string value, string dataType = "string")

Parameters

playerId CSteamID

The Steam ID of the target player.

key string

The data key.

value string

The data value.

dataType string

The data type identifier.

Returns

Task<bool>

A task that represents the asynchronous operation. The task result indicates whether the message was sent successfully.

Remarks

This is a convenience method that creates a DataSyncMessage internally.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

P2PException

Thrown when the message cannot be sent.

SendMessageToPlayerAsync(CSteamID, P2PMessage)

Sends a message to a specific player.

public Task<bool> SendMessageToPlayerAsync(CSteamID playerId, P2PMessage message)

Parameters

playerId CSteamID

The Steam ID of the target player.

message P2PMessage

The message to send.

Returns

Task<bool>

A task that represents the asynchronous operation. The task result indicates whether the message was sent successfully.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

P2PException

Thrown when the message cannot be sent.

SendTextMessageAsync(CSteamID, string)

Sends a simple text message to a player.

public Task<bool> SendTextMessageAsync(CSteamID playerId, string text)

Parameters

playerId CSteamID

The Steam ID of the target player.

text string

The text message to send.

Returns

Task<bool>

A task that represents the asynchronous operation. The task result indicates whether the message was sent successfully.

Remarks

This is a convenience method that creates a TextMessage internally.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

P2PException

Thrown when the message cannot be sent.

SetLobbyData(string, string)

Sets lobby-wide data that is accessible to all players.

public void SetLobbyData(string key, string value)

Parameters

key string

The data key.

value string

The data value.

Remarks

Only the lobby owner can set lobby data. This method will fail silently if called by a non-owner.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby or not the lobby owner.

SetMyData(string, string)

Sets data for the local player that is visible to all players.

public void SetMyData(string key, string value)

Parameters

key string

The data key.

value string

The data value.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby.

SetMyDataBatch(Dictionary<string, string>)

Sets multiple data values at once for the local player.

public void SetMyDataBatch(Dictionary<string, string> data)

Parameters

data Dictionary<string, string>

A dictionary containing key-value pairs to set.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby.

SyncModDataWithAllPlayers(string, string, string)

Synchronizes data with all players in the lobby. This is a non-async wrapper around SyncModDataWithAllPlayersAsync.

public void SyncModDataWithAllPlayers(string dataKey, string dataValue, string dataType = "string")

Parameters

dataKey string

The data key to synchronize.

dataValue string

The data value to synchronize.

dataType string

The data type identifier.

Remarks

This method is provided for backward compatibility. For new code, use SyncModDataWithAllPlayersAsync instead.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby.

SyncModDataWithAllPlayersAsync(string, string, string)

Synchronizes data with all players in the lobby. Useful for mod compatibility checks and data synchronization.

public Task SyncModDataWithAllPlayersAsync(string dataKey, string dataValue, string dataType = "string")

Parameters

dataKey string

The data key to synchronize.

dataValue string

The data value to synchronize.

dataType string

The data type identifier.

Returns

Task

A task that represents the asynchronous operation.

Remarks

This method both sets the local player's data and broadcasts it to all other players.

Exceptions

InvalidOperationException

Thrown when the client is not initialized.

LobbyException

Thrown when not in a lobby.

Events

OnLobbyCreated

Occurs when a new lobby is created.

public event EventHandler<LobbyCreatedEventArgs>? OnLobbyCreated

Event Type

EventHandler<LobbyCreatedEventArgs>

OnLobbyDataChanged

Occurs when lobby data is changed.

public event EventHandler<LobbyDataChangedEventArgs>? OnLobbyDataChanged

Event Type

EventHandler<LobbyDataChangedEventArgs>

OnLobbyJoined

Occurs when the local player joins a lobby.

public event EventHandler<LobbyJoinedEventArgs>? OnLobbyJoined

Event Type

EventHandler<LobbyJoinedEventArgs>

OnLobbyLeft

Occurs when the local player leaves a lobby.

public event EventHandler<LobbyLeftEventArgs>? OnLobbyLeft

Event Type

EventHandler<LobbyLeftEventArgs>

OnMemberDataChanged

Occurs when member data is changed.

public event EventHandler<MemberDataChangedEventArgs>? OnMemberDataChanged

Event Type

EventHandler<MemberDataChangedEventArgs>

OnMemberJoined

Occurs when a new member joins the current lobby.

public event EventHandler<MemberJoinedEventArgs>? OnMemberJoined

Event Type

EventHandler<MemberJoinedEventArgs>

OnMemberLeft

Occurs when a member leaves the current lobby.

public event EventHandler<MemberLeftEventArgs>? OnMemberLeft

Event Type

EventHandler<MemberLeftEventArgs>

OnP2PMessageReceived

Occurs when a P2P message is received from another player.

public event EventHandler<P2PMessageReceivedEventArgs>? OnP2PMessageReceived

Event Type

EventHandler<P2PMessageReceivedEventArgs>

OnVersionMismatch

Occurs when a version mismatch is detected between players in the lobby.

public event EventHandler<VersionMismatchEventArgs>? OnVersionMismatch

Event Type

EventHandler<VersionMismatchEventArgs>

Remarks

CRITICAL: This event indicates that players are using incompatible versions of SteamNetworkLib.

Version mismatches can cause serious issues including data corruption, synchronization failures, and networking errors.