Wednesday, 17 December 2025

Detecting AI Agent Terminals in PowerShell

Detecting AI Agent Terminals in PowerShell

Introduction

If you’re working with Visual Studio 2026, VS Code with Copilot, or other AI-assisted development tools, you may have noticed that these tools spawn terminal sessions for executing commands. I’ve created a PowerShell profile configuration that automatically detects these AI agent terminals and adjusts the experience accordingly.

Why This Matters

When an AI agent (like GitHub Copilot) runs commands in a terminal, you typically don’t need the full interactive experience - Oh My Posh themes, PSReadLine predictions, and fancy prompts just add overhead. Conversely, when you’re using the terminal, you want the full experience.

This profile script:

  • Detects AI agent terminals (VS Code Copilot, Visual Studio 2026 DevHub)
  • Displays a clear visual banner showing whether you or an AI is in control
  • Optimizes the environment based on the terminal type
  • Supports Nerd Fonts with ASCII fallbacks

The Setup

Step 1: Locate Your Profile

Open PowerShell and run:

$PROFILE

This shows the path to your profile script (typically ~\Documents\PowerShell\Microsoft.PowerShell_profile.ps1).

Step 2: Create or Edit Your Profile

If the file doesn’t exist:

New-Item -Path $PROFILE -ItemType File -Force
notepad $PROFILE

Step 3: Add the Configuration

Here’s the complete script broken down by section:

Mode Detection

# Detect Copilot/AI agent terminals
$script:parentProcessName = try { (Get-Process -Id $PID).Parent.Name } catch { $null }
$script:isCopilot = ($env:VSC_COPILOT_TERMINAL -eq "1") -or
                    ($env:VS_TERMINAL_AGENT -eq "1") -or
                    ($script:parentProcessName -eq "DevHub")

# Detect non-interactive/background terminals
$isNonInteractive = ($env:VSCODE_RESOLVING_TERMINAL -eq "1") -or
                    (-not [Environment]::UserInteractive)

This checks for:

  • VSC_COPILOT_TERMINAL - Set by VS Code for Copilot terminals
  • VS_TERMINAL_AGENT - Set by Visual Studio for agent terminals
  • DevHub parent process - Visual Studio 2026’s Copilot service

Visual Banner

The script displays a header banner showing who’s in control:

  • Blue “COPILOT AGENT” banner when an AI is running commands
  • Purple username banner for interactive sessions
if ($hasValidWindow) {
    $width = $Host.UI.RawUI.WindowSize.Width
    $time  = Get-Date -Format "HH:mm:ss"
    $user  = $env:USERNAME.ToUpper()

    if ($supportsNerdFonts) {
        $copilotIcon = [char]::ConvertFromUtf32(0xF166A)  # nf-md-robot
        $userIcon    = [char]::ConvertFromUtf32(0xF489)   # nf-oct-terminal
        $clockIcon   = [char]::ConvertFromUtf32(0xF1425)  # nf-md-clock_outline
    } else {
        $copilotIcon = "[BOT]"
        $userIcon    = ">"
        $clockIcon   = "@"
    }

    if ($script:isCopilot) {
        $leftLabel = " $copilotIcon COPILOT AGENT "
        $modeColor = "38;5;39"  # Blue
    } else {
        $leftLabel = " $userIcon $user "
        $modeColor = "38;5;99"  # Purple
    }

    $rightLabel = " $time $clockIcon "
    $fillCount = $width - $leftLabel.Length - $rightLabel.Length
    $fillLine  = if ($fillCount -gt 0) { [string]::new([char]0x2501, $fillCount) } else { "" }

    Write-Host ""
    Write-Host "`e[1;$($modeColor)m$leftLabel`e[0m`e[38;5;236m$fillLine`e[0m`e[90m$rightLabel`e[0m"
    Write-Host ""
}

If you have Nerd Fonts installed (Windows Terminal, VS Code), you’ll see nice icons; otherwise, ASCII fallbacks are used.

Conditional Setup

if ($script:isCopilot) {
    # Minimal prompt for AI agents
    function global:prompt {
        $Host.UI.RawUI.WindowTitle = "VS 2026 | Copilot"
        "PS $($PWD.Path)> "
    }
} else {
    # Full Oh My Posh experience for humans
    if (Get-Command oh-my-posh -ErrorAction SilentlyContinue) {
        $poshTheme = "$env:POSH_THEMES_PATH\marcduiker.omp.json"
        if (Test-Path $poshTheme) {
            oh-my-posh init pwsh --config $poshTheme | Invoke-Expression
        }
    }
}

The Complete Script

Here’s the full profile script you can copy:

# ============================================================================
# PowerShell Profile - AI Agent Detection
# ============================================================================

# ----------------------------------------------------------------------------
# 1. MODE DETECTION
# ----------------------------------------------------------------------------

$script:parentProcessName = try { (Get-Process -Id $PID).Parent.Name } catch { $null }
$script:isCopilot = ($env:VSC_COPILOT_TERMINAL -eq "1") -or
                    ($env:VS_TERMINAL_AGENT -eq "1") -or
                    ($script:parentProcessName -eq "DevHub")

$isNonInteractive = ($env:VSCODE_RESOLVING_TERMINAL -eq "1") -or
                    (-not [Environment]::UserInteractive)

$hasValidWindow = try { $Host.UI.RawUI.WindowSize.Width -gt 0 } catch { $false }

$supportsNerdFonts = ($env:WT_SESSION) -or
                     ($env:TERM_PROGRAM -eq "vscode") -or
                     ($env:VSAPPIDNAME -eq "devenv.exe") -or
                     ($env:ConEmuANSI -eq "ON")

# ----------------------------------------------------------------------------
# 2. HEADER BANNER
# ----------------------------------------------------------------------------

if ($hasValidWindow) {
    $width = $Host.UI.RawUI.WindowSize.Width
    $time  = Get-Date -Format "HH:mm:ss"
    $user  = $env:USERNAME.ToUpper()

    if ($supportsNerdFonts) {
        $copilotIcon = [char]::ConvertFromUtf32(0xF166A)
        $userIcon    = [char]::ConvertFromUtf32(0xF489)
        $clockIcon   = [char]::ConvertFromUtf32(0xF1425)
    } else {
        $copilotIcon = "[BOT]"
        $userIcon    = ">"
        $clockIcon   = "@"
    }

    if ($script:isCopilot) {
        $leftLabel = " $copilotIcon COPILOT AGENT "
        $modeColor = "38;5;39"
    } else {
        $leftLabel = " $userIcon $user "
        $modeColor = "38;5;99"
    }

    $rightLabel = " $time $clockIcon "
    $fillCount = $width - $leftLabel.Length - $rightLabel.Length
    $fillLine  = if ($fillCount -gt 0) { [string]::new([char]0x2501, $fillCount) } else { "" }

    Write-Host ""
    Write-Host "`e[1;$($modeColor)m$leftLabel`e[0m`e[38;5;236m$fillLine`e[0m`e[90m$rightLabel`e[0m"
    Write-Host ""
}

# ----------------------------------------------------------------------------
# 3. EARLY EXIT FOR NON-INTERACTIVE TERMINALS
# ----------------------------------------------------------------------------

if ($isNonInteractive) { return }

# ----------------------------------------------------------------------------
# 4. INTERACTIVE UI SETUP
# ----------------------------------------------------------------------------

if ($script:isCopilot) {
    function global:prompt {
        $Host.UI.RawUI.WindowTitle = "VS 2026 | Copilot"
        "PS $($PWD.Path)> "
    }
} else {
    if (Get-Module -ListAvailable -Name PSReadLine) {
        Import-Module PSReadLine -ErrorAction SilentlyContinue
        Set-PSReadLineOption -PredictionSource History -ErrorAction SilentlyContinue
        Set-PSReadLineOption -PredictionViewStyle ListView -ErrorAction SilentlyContinue
    }

    if (Get-Command oh-my-posh -ErrorAction SilentlyContinue) {
        $poshTheme = "$env:POSH_THEMES_PATH\marcduiker.omp.json"
        if (Test-Path $poshTheme) {
            oh-my-posh init pwsh --config $poshTheme | Invoke-Expression
        }
    }
}

# ----------------------------------------------------------------------------
# 5. ENCODING
# ----------------------------------------------------------------------------

$OutputEncoding = [Console]::OutputEncoding = [System.Text.UTF8Encoding]::new()

Prerequisites

For the full experience:

  1. Oh My Posh: winget install JanDeDobbeleer.OhMyPosh
  2. A Nerd Font: Download from nerdfonts.com and configure in your terminal
  3. Windows Terminal (recommended): winget install Microsoft.WindowsTerminal

Customization Tips

  • Change the theme to your preferred Oh My Posh theme
  • Adjust the colors by modifying the ANSI codes (38;5;39 for blue, 38;5;99 for purple)
  • Add additional detection methods if you use other AI tools

What It Looks Like

When Copilot is active (with Nerd Fonts):

 [robot-icon] COPILOT AGENT ━━━━━━━━━━━━━━━━━━━━━━━━━ 14:32:15 [clock-icon]

When you’re in control:

 > YOURNAME ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 14:32:15 [clock-icon]

(The actual icons render beautifully with Nerd Fonts installed!)

Conclusion

This small addition to your PowerShell profile makes it immediately clear whether you’re looking at a terminal session you control or one being operated by an AI assistant. It’s a simple quality-of-life improvement that becomes invaluable when working with modern AI-assisted development tools.

Feel free to adapt this to your needs - and share your improvements in the comments!

:memo: This article is also published on my personal blog: Detecting AI Agent Terminals in PowerShell

📝 Originally posted at: https://community.panoramicdata.com/t/detecting-ai-agent-terminals-in-powershell/116
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