Codex ACP Windows PowerShell setup for Obsidian Copilot Agent Mode

install-codex-agent-mode-windows.ps1

Set-StrictMode -Version Latest
$ErrorActionPreference = "Stop"
$ProgressPreference = "SilentlyContinue"

function Write-Step {
    param([string]$Message)
    Write-Host ""
    Write-Host "==> $Message"
}

function Add-PathEntryForThisSession {
    param([string]$PathEntry)

    $needle = $PathEntry.TrimEnd("\")
    foreach ($segment in $env:Path.Split(";", [System.StringSplitOptions]::RemoveEmptyEntries)) {
        if ($segment.TrimEnd("\") -ieq $needle) {
            return
        }
    }

    $env:Path = "$PathEntry;$env:Path"
}

function Find-CodexCommand {
    $candidatePaths = @()
    if (-not [string]::IsNullOrWhiteSpace($env:CODEX_INSTALL_DIR)) {
        $candidatePaths += (Join-Path $env:CODEX_INSTALL_DIR "codex.exe")
    }

    $candidatePaths += (Join-Path $env:LOCALAPPDATA "Programs\OpenAI\Codex\bin\codex.exe")
    $candidatePaths += (Join-Path $env:LOCALAPPDATA "OpenAI\Codex\bin\codex.exe")

    $localOpenAIBin = Join-Path $env:LOCALAPPDATA "OpenAI\Codex\bin"
    if (Test-Path -LiteralPath $localOpenAIBin -PathType Container) {
        $candidatePaths += Get-ChildItem -LiteralPath $localOpenAIBin -Directory -ErrorAction SilentlyContinue |
            ForEach-Object { Join-Path $_.FullName "codex.exe" }
    }

    $pathCommand = Get-Command "codex" -ErrorAction SilentlyContinue
    if ($null -ne $pathCommand -and -not [string]::IsNullOrWhiteSpace($pathCommand.Source)) {
        $candidatePaths += $pathCommand.Source
    }

    $seen = @{}
    $checked = @()
    foreach ($candidate in $candidatePaths) {
        if ([string]::IsNullOrWhiteSpace($candidate)) {
            continue
        }

        $key = $candidate.ToLowerInvariant()
        if ($seen.ContainsKey($key)) {
            continue
        }
        $seen[$key] = $true

        $checked += $candidate
        if (Test-Path -LiteralPath $candidate -PathType Leaf) {
            try {
                & $candidate --version *> $null
                if ($LASTEXITCODE -eq 0) {
                    return [PSCustomObject]@{
                        Bin  = Split-Path -Parent $candidate
                        Path = $candidate
                    }
                }
            } catch {
                continue
            }
        }
    }

    throw "A runnable codex.exe was not found. Checked: $($checked -join '; ')"
}

function Test-CodexLoggedIn {
    param([string]$CodexCommand)

    $previousErrorActionPreference = $ErrorActionPreference
    $ErrorActionPreference = "Continue"
    try {
        $status = & $CodexCommand login status 2>&1
        return ($LASTEXITCODE -eq 0 -and (($status -join "`n") -match "Logged in"))
    } catch {
        return $false
    } finally {
        $ErrorActionPreference = $previousErrorActionPreference
    }
}

function Wait-CodexLogin {
    param(
        [string]$CodexCommand,
        [int]$TimeoutSeconds = 600
    )

    $deadline = (Get-Date).AddSeconds($TimeoutSeconds)
    while ((Get-Date) -lt $deadline) {
        if (Test-CodexLoggedIn -CodexCommand $CodexCommand) {
            return
        }

        Start-Sleep -Seconds 2
    }

    throw "Codex login was not completed within $TimeoutSeconds seconds. Run this script again after signing in."
}

Write-Step "Installing Codex CLI"
$previousNonInteractive = $env:CODEX_NON_INTERACTIVE
$env:CODEX_NON_INTERACTIVE = "1"
try {
    Invoke-RestMethod "https://github.com/openai/codex/releases/latest/download/install.ps1" | Invoke-Expression
} finally {
    if ([string]::IsNullOrWhiteSpace($previousNonInteractive)) {
        Remove-Item Env:\CODEX_NON_INTERACTIVE -ErrorAction SilentlyContinue
    } else {
        $env:CODEX_NON_INTERACTIVE = $previousNonInteractive
    }
}

$resolvedCodex = Find-CodexCommand
$codexBin = $resolvedCodex.Bin
$codex = $resolvedCodex.Path
Add-PathEntryForThisSession -PathEntry $codexBin

Write-Step "Signing in to Codex"
if (Test-CodexLoggedIn -CodexCommand $codex) {
    Write-Host "Codex is already signed in."
} else {
    Write-Host "Follow the Codex login prompts. This script will continue after login finishes."
    & $codex login
    Wait-CodexLogin -CodexCommand $codex
}

Write-Step "Installing codex-acp"
$arch = if ([System.Runtime.InteropServices.RuntimeInformation]::OSArchitecture -eq "Arm64") {
    "aarch64"
} else {
    "x86_64"
}
$acpDir = Join-Path $env:LOCALAPPDATA "Programs\codex-acp"
$zip = Join-Path $env:TEMP "codex-acp.zip"

$release = Invoke-RestMethod "https://api.github.com/repos/zed-industries/codex-acp/releases/latest"
$asset = $release.assets |
    Where-Object { $_.name -like "codex-acp-*-$arch-pc-windows-msvc.zip" } |
    Select-Object -First 1

if ($null -eq $asset) {
    throw "No codex-acp Windows release was found for $arch."
}

New-Item -ItemType Directory -Force -Path $acpDir | Out-Null
Invoke-WebRequest -Uri $asset.browser_download_url -OutFile $zip
Expand-Archive -Path $zip -DestinationPath $acpDir -Force

$acp = Join-Path $acpDir "codex-acp.exe"
if (-not (Test-Path -LiteralPath $acp -PathType Leaf)) {
    throw "codex-acp.exe was not found at $acp"
}

try {
    Set-Clipboard -Value $acp
    $clipboardMessage = "The codex-acp.exe path has been copied to your clipboard."
} catch {
    $clipboardMessage = "Copy this codex-acp.exe path:"
}

Write-Host ""
Write-Host "Done. $clipboardMessage"
Write-Host $acp
Write-Host ""
Write-Host "Next: Obsidian -> Settings -> Copilot -> Agents -> Codex -> Configure"
Write-Host "Paste this path into the binary path field, leave Environment variables empty, then save."