Cwd always gets set even when WorkingDirectory is null

[IeuanWalker]

When creating a session i set working directory to null but it always sets to the cwd in workspace.yaml to the app’s own launch directory.

i.e. when debugging sets it too C:\Users\c773975\source\repos\GHMine\App\src\App\bin\Debug\net10.0-windows10.0.19041.0\win-x64 and when installed too C:\Program Files\App

Id expect it too be null as intended, not sure if this has an effect on token usage etc.
Purpose of setting it too null is to have a simple chat that doesn't relate to a specific project/ folder/ file

This causes issues when resuming a session as the session context is now different, changing the behaviour of the app (WorkingDirectory is no longer null, and during debug GitRoot/ Repository and branch are also populated).

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Im using the latest .NET nuget package

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Im guessing the issue is within the CLI it self, looking at the code i dont see anything in the SDK that mutates the WorkingDirectory

[github-actions]

Investigation findings

Thanks for the detailed report. I investigated the relevant code paths in the .NET SDK.

What I looked at

• dotnet/src/Types.cs — CopilotClientOptions.WorkingDirectory (line 309) and SessionConfigBase.WorkingDirectory (line 2892)
• dotnet/src/Client.cs — how WorkingDirectory is used when spawning the CLI process (line 1837) and in CreateSessionRequest/ResumeSessionRequest (lines 972, 1170)
• dotnet/README.md — documentation for both properties

What's happening

There are two distinct WorkingDirectory properties in the SDK that interact to produce the behaviour you're seeing:

1. CopilotClientOptions.WorkingDirectory — sets the OS working directory for the spawned CLI process (used in ProcessStartInfo.WorkingDirectory). When null, .NET inherits the calling app's current working directory.

2. SessionConfigBase.WorkingDirectory — sent to the CLI as part of the session.create / session.resume RPC request to tell it the session's working directory. When null, the SDK correctly passes no value, but the CLI then falls back to its own process working directory (the one determined by point 1 above).

You're correct that the SDK itself does not mutate WorkingDirectory — the value you set (including null) is passed through faithfully. However, when null is sent, the CLI interprets that as "use the runtime process cwd", which ends up being your app's binary directory.

Root cause: documentation gap

The current documentation does not explain this fallback behaviour:

• SessionConfigBase.WorkingDirectory is documented only as "Working directory for the session." with no explanation of what null means.
• The README only documents CopilotClientOptions.WorkingDirectory as "Working directory for the runtime process." — the session-level property is not mentioned at all.
• The only hint of the null-fallback behaviour is buried in the PluginDirectories remarks: "Relative paths resolve against WorkingDirectory (or the runtime cwd if unset)."

There is no documented way to create a truly "project-agnostic" chat session, and the distinction between the two WorkingDirectory settings is not explained anywhere.

Reclassification

This is reclassified as a documentation issue. The SDK and CLI are behaving as designed, but the documentation gap is what caused the confusion.

Recommended documentation improvements

The docs should be updated to:

1. Clarify that SessionConfigBase.WorkingDirectory = null means "the CLI will use its own process working directory", not "no working directory".
2. Document the difference between CopilotClientOptions.WorkingDirectory (process cwd) and SessionConfigBase.WorkingDirectory (session cwd).
3. Add guidance for project-agnostic chat sessions — e.g. explicitly setting a stable neutral directory (such as a temp path or user home) and setting EnableConfigDiscovery = false to prevent git/project context from being picked up.

Workaround (for now)

If you want a session that isn't associated with a project, set both properties explicitly to a neutral directory and disable config discovery:

var client = new CopilotClient(new CopilotClientOptions
{
    WorkingDirectory = Path.GetTempPath() // CLI process cwd — avoids picking up project files
});

var session = await client.CreateSessionAsync(new SessionConfig
{
    WorkingDirectory = Path.GetTempPath(), // session cwd — avoids git/repo context
    EnableConfigDiscovery = false          // prevents picking up .mcp.json, skills, etc.
});

This ensures consistent behaviour on both session creation and resumption.

Generated by Bug Handler for issue #1735 · sonnet46 1.4M · ◷