Session Class

This is the main interface class of the WinSCP assembly.

It represents a session and provides methods for manipulating remote files over SFTP, FTP, WebDAV, S3 or SCP session.



Namespace: WinSCP

public sealed class Session : IDisposable
Public NotInheritable Class Session
    Implements IDisposable


Name Description
Session() Default constructor.


Name Description
string AdditionalExecutableArguments Additional command-line arguments to be passed to In general, this should be left with default null.
string DebugLogLevel Logging level of debug log to. The default value is 0. The maximal logging level is 2.
string DebugLogPath Path to store assembly debug log to. Default null means, no debug log file is created. See also SessionLogPath. The property has to be set before calling Open.
bool DefaultConfiguration Deprecated. Do not use. Use Session.AddRawConfiguration instead.
bool DisableVersionCheck Deprecated. Disables test that WinSCP executables have the same product version as this assembly.1 The property has to be set before calling Open.
string ExecutablePath Path to winscp.exe. The default is null, meaning that winscp.exe is looked for in the same directory as this assembly or in an installation folder. The property has to be set before calling Open.
string ExecutableProcessUserName If the .NET process is running in an impersonated environment, you need to provide credentials of the impersonated account, so that the winscp.exe process can be started with the same privileges.
SecureString ExecutableProcessPassword See ExecutableProcessUserName.
string HomePath Path to a remote home directory. The property can be read only after calling Open.
string IniFilePath Deprecated. Do not use. Use Session.AddRawConfiguration instead.
string SessionLogPath Path to store session log file to. Default null means, no session log file is created. See also DebugLogPath. The property has to be set before calling Open.
bool Opened Is session opened yet? true, when Open was successfully called already. Read-only.
StringCollection Output Output of WinSCP console session. See also OutputDataReceived event. Read-only.
TimeSpan ReconnectTime Sets time limit in seconds to try reconnecting broken sessions. Default is 120 seconds. Use TimeSpan.MaxValue to remove any limit. The property has to be set before calling Open.
int ReconnectTimeInMilliseconds Alternative to ReconnectTime. Particularly useful for COM hosts, that cannot use TimeSpan, such as Visual Basic.
TimeSpan Timeout Maximal interval between two consecutive outputs from WinSCP console session, before TimeoutException is thrown. The default is one minute. It’s not recommended to change the value. For session/connection timeout, see SessionOptions.Timeout. When SessionOptions.Timeout is longer, its value is used instead (in beta version only).


Name Description
Abort Forcefully aborts session.
AddRawConfiguration Allows setting any configuration settings using raw format as in an INI file.
CalculateFileChecksum Calculates a checksum of a remote file.
CreateDirectory Creates remote directory.
Close Closes session.
CombinePaths Combines strings into a remote path.
Dispose Closes session and disposes object.
DuplicateFile Duplicates remote file to another remote directory.
EscapeFileMask Converts special characters in file path to make it unambiguous file mask/wildcard.
EnumerateRemoteFiles Recursively enumerates remote files.
ExecuteCommand Executes command on the remote server.
FileExists Checks for existence of remote file.
GetFileInfo Retrieves information about remote file.
GetFiles Downloads files.
ListDirectory Lists remote directory.
MoveFile Moves remote file to another remote directory and/or renames remote file.
Open Opens the session.
PutFiles Uploads files.
RemoveFiles Removes remote files.
ScanFingerprint Scans a fingerprint of SSH server public key or FTPS/WebDAVS TLS certificate.
SynchronizeDirectories Synchronizes local directory with remote directory.
TranslateLocalPathToRemote Generates a remote path equivalent of a local path, given root paths.
TranslateRemotePathToLocal Generates a local path equivalent of a remote path, given root paths.


Name Description
Failed Occurs on error during any operation.
FileTransferProgress Occurs regularly during file transfer to report transfer progress.
FileTransferred Occurs when file is transferred.
OutputDataReceived Occurs on output from WinSCP console session.
QueryReceived Occurs when a decision is needed (i.e. typically on any non-fatal error).


To use the class:

  • Create an instance of SessionOptions and fill in all needed information to connect and authenticate the session automatically;
  • Create an instance of Session class;
  • Usually all properties of Session can be left with their default values;
  • Assign event handlers, if continuous monitoring of operation is required;
  • Call Open method passing instance of SessionOptions;
  • Use any file manipulation methods you need, such as GetFiles, PutFiles, SynchronizeDirectories.

The class is locked against concurrent accesses from multiple threads. Though you can use several instances of the class in parallel, even from different threads.

Capturing Results of Operations

There are two classes of operations, hence two classes of methods; atomic operations, such as Open, ListDirectory, etc; and batch operations, such as GetFiles, PutFiles, SynchronizeDirectories, etc.

Methods from both classes throw SessionLocalException on error in communication with WinSCP console session.

Methods for atomic operations throw SessionRemoteException on error originating from WinSCP console session (referred to as “failure” below).

Methods for batch operations returns an instance of descendant of OperationResultBase class (such as TransferOperationResult or SynchronizationResult). Such result class stores list of operations performed (e.g. TransferOperationResult.Uploads), and list of failures (OperationResultBase.Failures).

Every structure representing operation performed may refer (e.g. in TransferEventArgs.Error) to one of the failures, if the failure can be explicitly associated with the operation. So often the same failure (represented by SessionRemoteException) will be referenced twice in the results.

But there can be failures that cannot be explicitly associated with any operation represented in results. An example is an error when listing contents of remote directory to determine list of files to downloads. The listing is not represented in the results, so the failure will be included only in a generic list of failures.

If you do not want to check the list of failures after every batch operation method call, you can use method OperationResultBase.Check to throw the first failure in the list, if any failure occurred:

// Throw, if upload fails
session.PutFiles(localPath, remotePath).Check();

Also for all failures the Session.Failed event is raised.

The batch operation though typically aborts on the first major failure. To customize error processing, handle Session.QueryReceived. For an example, see Recursively download directory tree with custom error handling.


For simple handling of errors, see overall example for WinSCP .NET assembly or any other example.

For example how to check and print errors, but continue, see real-life example Search recursively for text in remote directory / Grep files over SFTP/FTP protocol.

  1. Note, even if you set this property, you need to use the assembly with compatible WinSCP executable only. Otherwise the behavior is unpredictable. In general, it is not recommended to use this. In neither case will you be able to use the assembly with WinSCP 5.0.4 or older.Back

Last modified: by martin