fix(cli): give the Windows service a hidden console by neriousy · Pull Request #52594 · anomalyco/opencode

neriousy · 2026-10-01T23:49:31Z

Issue for this PR

Closes #51887
Closes #50868
Refs #42440, #45259

Type of change

Bug fix
New feature
Refactor / code improvement
Documentation

What does this PR do?

Problem. Clients start the shared service with detached: true (packages/client/src/service-contender.ts). On Windows that is DETACHED_PROCESS, so the service has no console. Every console program it starts without CREATE_NO_WINDOW (windowsHide) then gets a new visible console window (a conhost window or a Windows Terminal tab that steals focus).

Core's own spawns already pass windowsHide (cross-spawn-spawner.ts). The reports come from processes we don't control:

plugin code using Bun.spawn / $ / child_process (omo running tasklist in [Bug] OpenCode2 CLI Endlessly Pops Up Windows on Windows #51887, rtk.ts and herdr-agent-state.js on every shell command in windows: console window flashes on every subprocess spawn (v2 next build) #42440, oh-my-opencode-slim)
user hooks and harness scripts (git rev-parse guards)
npm's git ls-remote / git clone for git plugin specs (server: unpinned plugin update check flashes visible git console window on Windows #50868)

In v1 the server ran inside the TUI's console, so all of these were invisible. That's also why --standalone makes the flashing disappear. Adding windowsHide to the service spawn (#45259) doesn't work, because Windows ignores CREATE_NO_WINDOW when it's combined with DETACHED_PROCESS. Dropping detached doesn't work either: libuv puts non-detached children in a kill-on-close job, so the service would die with the CLI.

Fix. When running as serve --service on Windows, the service calls AllocConsoleWithOptions(ALLOC_CONSOLE_MODE_NO_WINDOW) at startup, before anything is spawned. The service now has a console with no window, and processes it starts share it instead of allocating their own. This covers plugins, hooks, MCP launch chains and npm's git calls without each call site having to set windowsHide. Desktop starts the service through serve --service too, so it's covered.

The standard handles are saved before the call and restored after it. That keeps the stderr pipe the client reads startup errors from.
Only on Windows 11 24H2 / Server 2025 (build 26100+), where AllocConsoleWithOptions exists. Older builds skip it and keep today's behavior. The older fallback (AllocConsole + hide) would likely flash once at startup, and with Windows Terminal as the default terminal it could leave a visible tab, so I left it out.
The Node build (opencode-node) gets a no-op through the #hidden-console import, the same way packages/core handles #pty.

How did you verify your code works?

bun typecheck in packages/cli
bun test test/service.test.ts test/import-boundaries.test.ts test/standalone.test.ts in packages/cli
Checked that Bun resolves #hidden-console to the Bun file and Node to the no-op file; on macOS the call is a no-op

Not yet verified on Windows. This is a draft until someone tests it on Windows 11 24H2+:

opencode service stop
Start the dev CLI so it starts its own service
Configure a plugin that spawns without windowsHide (omo, rtk.ts) and/or an unpinned git plugin such as superpowers@git+https://github.com/obra/superpowers.git
Run shell tool calls and start a local MCP server
Expect no console windows, and no could not attach a hidden console warning in the service log

Screenshots / recordings

N/A

Checklist

I have tested my changes locally (Windows run still pending)
I have not included unrelated changes in this PR

mlalpho · 2026-10-02T02:34:51Z

confirmed this is fixed by this PR on my windows 26100.8328

Cheers! 🍻

neriousy · 2026-10-02T11:28:16Z

Hi @mlalpho - how did you test it? I have a hard time reproducing the windows popping up

mlalpho · 2026-10-02T12:27:55Z

hi @neriousy , i was hitting pretty regularly so didn't have trouble.

watching conhost fires:

powershell -ExecutionPolicy Bypass -File watch-conhost.ps1 -Seconds 300

# Watch for new conhost.exe processes (visible console windows) while testing
# the OpenCode desktop app. Run this in a PowerShell window, then exercise the
# app (agent commands, Code Mode tool calls). New conhost entries with a real
# parent chain indicate a console window was allocated. ConPTY sessions also
# create conhost.exe entries; the parent/command line distinguishes them.
#
# Usage: powershell -ExecutionPolicy Bypass -File watch-conhost.ps1 -Seconds 180

param(
  [int]$Seconds = 180
)

$ErrorActionPreference = "SilentlyContinue"
$query = "SELECT * FROM __InstanceCreationEvent WITHIN 1 WHERE TargetInstance ISA 'Win32_Process' AND TargetInstance.Name LIKE 'conhost%'"

Write-Host "Watching for new conhost.exe processes for $Seconds seconds..."
Write-Host "Exercise the app now (run agent commands, Code Mode tool calls)."
Write-Host ""

$watcher = New-Object System.Management.ManagementEventWatcher($query)
$count = 0
$sw = [System.Diagnostics.Stopwatch]::StartNew()

while ($sw.Elapsed.TotalSeconds -lt $Seconds) {
  try {
    $event = $watcher.WaitForNextEvent()
    $p = $event.TargetInstance
    $count++
    $parentPid = $p.ParentProcessId
    $parent = Get-CimInstance Win32_Process -Filter "ProcessId=$parentPid"
    $parentName = "<pid $parentPid exited>"
    if ($parent) { $parentName = $parent.Name + " (" + $parent.CommandLine + ")" }
    $cmd = $p.CommandLine
    if (-not $cmd) { $cmd = "" }
    if ($cmd.Length -gt 160) { $cmd = $cmd.Substring(0, 160) + "..." }
    Write-Host ("[{0}] conhost pid={1}" -f (Get-Date -Format "HH:mm:ss.fff"), $p.ProcessId)
    Write-Host ("        parent: {0}" -f $parentName)
    Write-Host ("        cmd:    {0}" -f $cmd)
  } catch [System.Management.ManagementException] {
    # query poll timeout; continue
  }
}

Write-Host ""
Write-Host ("Done. Total new conhost.exe processes observed: {0}" -f $count)
Write-Host "Notes:"
Write-Host " - conhost with parent opencode-cli.exe/opencode.exe + no '--headless' can be a visible flash (bug)"
Write-Host " - conhost parents under \WindowsApps or with ConPTY handles are usually hidden pseudoconsoles"

This is the prompt i sent to the session while running the opencode beta build i made from this pr's commit:

running prompt A/B (on production and beta and watching conhost log and checking for popups before and after:

Run this diagnostic sequence exactly, in order, and report the result of each step.
Do not skip or batch steps.

1. Run this shell command: git -C <folder> status --porcelain
2. Run this shell command: node --version
3. Run this shell command: curl --version
4. Using Code Mode execute the commands
   "git rev-parse HEAD", "git log --oneline -3", and "node -e \"console.log(2+2)\""
5. Read <folder>\README.md using <custom v2 tool>
6. Run an <custom tool> thru <opencode v2 plugin>
7. Run "git -C <folder> diff --stat" five separate times
8. Summarize each step's outcome in one line each

neriousy · 2026-10-02T12:29:35Z

But this doesn't help me. it doesnt pop up windows for me. Do you use any plugins?

mlalpho · 2026-10-02T12:46:00Z

yes, in this test it loaded 3 plugins that work on v2. only two plugin tools 'custom file reading tool' and 'custom shell tool' were exercised by this prompt. the rest were via native tool calls or code mode.

i'm rerunning on project that doesn't load plugins locally.

mlalpho · 2026-10-02T13:49:42Z

well dang, I can't reproduce without these plugins loaded (empty project folder) ... i can still confirm the fix works. it looks like i might be seeing a tool.execute.before hook that spawns a cmd.exe wrapper with node's execSync

neriousy · 2026-10-02T13:52:12Z

welcome to my world lol! Like I feel like I'm onto somethig but not quite

mlalpho · 2026-10-02T13:54:26Z

good luck ! i'll let you if i find anything more concrete. looking forward to this fix lol

neriousy · 2026-10-02T13:57:50Z

you can try cleaning your .opencode/plugins directories maybe that will do smth

mlalpho · 2026-10-02T14:04:35Z

I found the underlying script that the plugin was running. the call site for execSync needed an explicit 'windowsHide: true' .. which is what this PR fixes at a lower level. at the moment its up to plugin developers to play whack-a-mole with windowsHide params and exec*Sync calls (or similar spawn sites)

This particular script was called by the tool.execute.before hook so it looked like almost all tools were causing.

fix(cli): give the Windows service a hidden console

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github-actions Bot added the contributor label Oct 1, 2026

github-actions Bot mentioned this pull request Oct 1, 2026

📊 AI CLI 工具社区动态日报 2026-10-02 litang9/big_model_radar#483

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opencode-agent Bot mentioned this pull request Oct 7, 2026

Windows 11: Plugin subprocess spawns flash terminal windows #53730

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fix(cli): give the Windows service a hidden console - #52594

fix(cli): give the Windows service a hidden console#52594
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neriousy commented Oct 1, 2026

Issue for this PR

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Screenshots / recordings

Checklist

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