Hide CLI console window on Windows across all SDKs

[Copilot]

Windows GUI applications show a console window when the SDK auto-starts the CLI subprocess, breaking the user experience for frozen apps.

Changes

All SDKs now automatically hide the console window on Windows when spawning the CLI subprocess:

• Python: Uses subprocess.CREATE_NO_WINDOW flag unconditionally on Windows
• Node.js: Uses windowsHide: true in spawn options
• Go: Uses SysProcAttr.HideWindow via platform-specific build tags
• .NET: Already had CreateNoWindow = true (no changes needed)

Implementation

Python

Uses conditional kwargs pattern to avoid passing Windows-specific parameters on other platforms:

popen_kwargs = {"cwd": self.options["cwd"], "env": env}

if sys.platform == "win32":
    popen_kwargs["creationflags"] = subprocess.CREATE_NO_WINDOW

self._process = subprocess.Popen(args, **popen_kwargs)

Node.js

this.cliProcess = spawn(command, spawnArgs, {
    stdio: ...,
    cwd: this.options.cwd,
    env: envWithoutNodeDebug,
    windowsHide: true,
});

Go

Platform-specific files with build tags:

• process_windows.go: Sets SysProcAttr.HideWindow = true
• process_other.go: No-op on non-Windows platforms

Behavior

The console window is now automatically hidden on Windows across all SDKs, ensuring a consistent user experience in GUI applications. No configuration required.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Copilot CLI subprocess opens console window when SDK auto-starts CLI</issue_title>
<issue_description>When using the Python SDK on Windows in a frozen app, a console window pops up and stays open whenever the SDK auto-starts the Copilot CLI server. This happens because the CLI is spawned via subprocess.Popen(...) without CREATE_NO_WINDOW/STARTUPINFO

Relevant lines:
https://github.com/github/copilot-sdk/blob/main/python/copilot/client.py#L927-L935
https://github.com/github/copilot-sdk/blob/main/python/copilot/client.py#L939-L946

The console window is visible and distracts end users. This is especially noticeable in GUI apps that shouldn’t show any terminal windows.

Could you add an option to suppress the window on Windows? For example:

• A client option like hide_cli_window: true, or
• Passing creationflags=subprocess.CREATE_NO_WINDOW / startupinfo when launching the CLI on Windows</issue_description>

<agent_instructions>Review the issue and implement the change.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Copilot CLI subprocess opens console window when SDK auto-starts CLI #305

---

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[SteveSandersonMS]

@copilot This shouldn't be an option. The SDK should always hide the window. Check this is consistent across all the 4 language SDKs.

[Copilot]

@copilot This shouldn't be an option. The SDK should always hide the window. Check this is consistent across all the 4 language SDKs.

Done! I've made hiding the CLI window the default behavior across all SDKs:

Python: Removed the hide_cli_window option - now always hides on Windows (586f262)
Node.js: Added windowsHide: true to spawn options (586f262)
Go: Added platform-specific configureProcAttr with HideWindow on Windows (586f262)
.NET: Already had CreateNoWindow = true ✓

All SDKs now consistently hide the console window on Windows to avoid distracting users in GUI apps.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/copilot_internal/user
  • Triggering command: /opt/hostedtoolcache/node/22.22.0/x64/bin/node node /home/REDACTED/work/copilot-sdk/copilot-sdk/nodejs/node_modules/@github/copilot/index.js --server --log-level info --stdio _cgo_.o (http block)
  • Triggering command: /opt/hostedtoolcache/node/22.22.0/x64/bin/node node /home/REDACTED/work/copilot-sdk/copilot-sdk/nodejs/node_modules/@github/copilot/index.js --server --log-level info --stdio e.go ux_amd64/compile --gdwarf-5 --64 -o ux_amd64/compile 4484�� ache/go/1.24.13/x64/src/net -I ache/just/1.46.0/x64/node --gdwarf-5 --64 -o 4484424/b110/_x0remote (http block)
  • Triggering command: /opt/hostedtoolcache/node/22.22.0/x64/bin/node node /home/REDACTED/work/copilot-sdk/copilot-sdk/nodejs/node_modules/@github/copilot/index.js --server --log-level info --stdio -I ux_amd64/vet --gdwarf-5 li_window option-1 ut-2373211685.c ux_amd64/vet -qui�� lotsdk-nodejs.ts /tmp/go-build1154484424/b110/ x64/pkg/tool/linux_amd64/vet . -imultiarch x86_64-linux-gnu x64/pkg/tool/linux_amd64/vet (http block)
• https://api.github.com/user
  • Triggering command: /opt/hostedtoolcache/node/22.22.0/x64/bin/node node /home/REDACTED/work/copilot-sdk/copilot-sdk/nodejs/node_modules/@github/copilot/index.js --server --log-level info --stdio t-estree/dist/simple-traverse.d.ts t-estree/dist/ts-estree/index.d.ts t-estree/dist/tsgrep t-estree/dist/ts-l t-estree/dist/noSysProcAttr\|HideWindow t-estree/dist/clgo/e2e/testharness/proxy.go t-es�� t-estree/dist/semantic-or-syntactic-errors.d.ts t-estree/dist/use-at-your-own-risk.d.ts t-estree/dist/version.d.ts t-estree/dist/usbash t-estree/dist/ve--norc t-estree/dist/so--noprofile t-estree/dist/create-program/valgo/jsonrpc.go (http block)
  • Triggering command: `/opt/hostedtoolcache/node/22.22.0/x64/bin/node node /home/REDACTED/work/copilot-sdk/copilot-sdk/nodejs/node_modules/@github/copilot/index.js --server --log-level info --stdio indow on Windows (removed hide_cli_window option)

• Node.js: Add windowsHide: true to spawn options
• Go: Add SysProcAttr with HideWindow on Windows via platform-specific file x64/pkg/tool/lin-o` (http block)

• Triggering command: /opt/hostedtoolcache/node/22.22.0/x64/bin/node node /home/REDACTED/work/copilot-sdk/copilot-sdk/nodejs/node_modules/@github/copilot/index.js --server --log-level info --stdio go/e2e/testharness/helper.go ache/go/1.24.13/x64/pkg/tool/lin-o (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
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[github-actions]

✅ Cross-SDK Consistency Review

This PR maintains excellent cross-SDK consistency by implementing the same feature (hiding CLI console window on Windows) across all four SDK implementations.

Implementation Summary

All SDKs now automatically hide the console window on Windows when spawning the CLI subprocess:

SDK	Implementation	Mechanism
Python	✅ Added	subprocess.CREATE_NO_WINDOW (conditional on sys.platform == "win32")
Node.js	✅ Added	windowsHide: true in spawn options
Go	✅ Added	SysProcAttr.HideWindow = true (platform-specific with build tags)
.NET	✅ Already present	CreateNoWindow = true (no changes needed)

Why This Is Well Done

1. Feature parity: All four SDKs now provide the same user experience on Windows
2. Idiomatic implementations: Each SDK uses the platform-appropriate approach:
   • Python: Runtime platform check with conditional kwargs
   • Node.js: Built-in windowsHide option (cross-platform safe)
   • Go: Build tags for compile-time platform selection
   • .NET: ProcessStartInfo property
3. No configuration needed: The behavior is automatic and sensible (no user-facing API changes)
4. Consistent comments: Each implementation includes similar explanatory comments

No Action Required

This PR successfully brings all SDKs into alignment. No additional cross-SDK changes are needed. 🎉

AI generated by SDK Consistency Review Agent

[Copilot]

Pull request overview

This PR improves Windows GUI/frozen-app UX by ensuring the Copilot CLI subprocess does not pop up a visible console window when auto-started by the SDKs, aligning behavior across Python, Node.js, and Go (with .NET already compliant).

Changes:

• Python: pass creationflags=subprocess.CREATE_NO_WINDOW on Windows when spawning the CLI.
• Node.js: add windowsHide: true to the CLI spawn options for both .js and executable CLI paths.
• Go: introduce platform-specific configureProcAttr helpers to set SysProcAttr.HideWindow = true on Windows and call it from CLI process startup.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
python/copilot/client.py	Hides Windows console window via creationflags when spawning the CLI subprocess.
nodejs/src/client.ts	Ensures spawned CLI process uses windowsHide: true on Windows.
go/process_windows.go	Windows-only helper that sets SysProcAttr.HideWindow on the CLI exec command.
go/process_other.go	Non-Windows no-op implementation of the process attribute helper.
go/client.go	Calls the platform-specific helper before starting the CLI process.