Windows: CLI agent connect fails — resolve_cli picks extensionless npm shim before .cmd/.exe

[OldSuns]

Summary

On Windows, connecting OpenCode / Claude Code / Codex in the desktop app fails even when the CLIs work fine in a terminal.

OpenCode error shown in UI:

No models configured in OpenCode. Run "opencode" to set up

(Claude/Codex fail for the same root cause when installed via npm.)

Root cause

resolve_cli in crates/op-host-services/src/model_discovery.rs tries Windows extensions in this order:

[", ".exe", ".cmd", ".bat"]

npm global installs put an extensionless Unix shell script (#!/bin/sh) next to the real Windows entry:

Path	What it is
%APPDATA%\npm\opencode	Unix shim — not a valid Win32 PE
%APPDATA%\npm\opencode.cmd	Real Windows launcher
...\node_modules\opencode-ai\bin\opencode.exe	Real binary

Because candidate.is_file() is true for the extensionless shim, resolve_cli returns that path first. Command::new(exe).arg("models").output() then fails (invalid application for this OS), discover_opencode() gets an empty list, and connect_opencode() reports “No models configured…”.

Terminal works because PowerShell/CMD prefer .ps1 / .cmd, not the bare shim.

Same pattern for claude and codex under %APPDATA%\npm\.

Repro

1. Windows 10/11
2. Install CLIs via npm, e.g. npm i -g opencode-ai (and/or Claude Code / Codex)
3. Confirm terminal works: opencode models lists provider/model lines
4. Launch OpenPencil desktop (Start Menu / shortcut is enough)
5. Settings → connect OpenCode

Expected: models listed, connect succeeds
Actual: No models configured in OpenCode. Run "opencode" to set up

Local proof (CreateProcess-style)

# Fails — bare npm shim is a shell script
Start-Process -FilePath "$env:APPDATA\npm\opencode" -ArgumentList models -NoNewWindow -Wait
# → not a valid application for this OS platform

# Works
& "$env:APPDATA\npm\opencode.cmd" models
& "$env:APPDATA\npm\node_modules\opencode-ai\bin\opencode.exe" models

Workaround

Rename/remove the extensionless shims so resolution falls through to .cmd:

cd $env:APPDATA\npm
Rename-Item opencode opencode.sh.bak -ErrorAction SilentlyContinue
Rename-Item claude claude.sh.bak -ErrorAction SilentlyContinue
Rename-Item codex codex.sh.bak -ErrorAction SilentlyContinue

Then fully quit and restart OpenPencil.

Suggested fix

On Windows, do not treat extensionless files as executables in resolve_cli (or try .exe / .cmd / .bat before ""`).

Minimal change sketch:

// windows: prefer real PE / cmd shims over npm's extensionless #!/bin/sh
let exts: &[&str] = if cfg!(windows) {
    &[".exe", ".cmd", ".bat", "]  // or drop " entirely on Windows
} else {
    &["]
};

Optionally also prefer resolving through to the real .exe under node_modules\...\bin\ when the hit is an npm shim.

Environment (reporter)

• OpenPencil desktop (latest pre-release, e.g. v0.8.2)
• Windows (win32)
• opencode 1.18.7 via npm (%APPDATA%\npm)
• opencode models works in PowerShell and lists many models
• Config present at %USERPROFILE%\.config\opencode\opencode.json (not the old ~\.opencode\config.json path the UI hint mentions)

Related code

• crates/op-host-services/src/model_discovery.rs — resolve_cli, discover_opencode
• crates/op-host-services/src/provider_probe.rs — connect_opencode empty-models message
• crates/op-host-services/src/cli_resolver_windows.rs — GUI PATH fallbacks (includes %APPDATA%\npm, which is correct; the bug is extension order)

Thanks!

[Kayshen-X]

Thanks for the thorough report and the clear reproduction details. Your diagnosis makes sense: on Windows we should not prefer npm’s extensionless shell shim over the native .exe / .cmd / .bat launchers.

We’ll update resolve_cli to use Windows-specific resolution order and add regression coverage for this npm shim layout. The workaround is also very helpful in the meantime. Thanks again for tracking this down!