Block AI Tools with Hosts Files at the OS Level

#!/bin/bash
# ai-hosts-update.sh — Daily hosts file update for AI tool blocking
# Add to cron: 0 4 * * * /usr/local/bin/ai-hosts-update.sh

API_KEY="YOUR_API_KEY"
HOSTS_FILE="/etc/hosts"
BACKUP_DIR="/var/backups/hosts"
MARKER_START="# === AI TOOLS BLOCKLIST START ==="
MARKER_END="# === AI TOOLS BLOCKLIST END ==="

# Create backup directory if needed
mkdir -p "$BACKUP_DIR"

# Backup current hosts file
cp "$HOSTS_FILE" "$BACKUP_DIR/hosts.$(date +%Y%m%d)"

# Download latest AI domains in hosts format
curl -sf -H "Authorization: Bearer $API_KEY" \
  "https://api.aitoolsblocklist.com/v1/feed?format=hosts" \
  -o /tmp/ai-hosts-block.txt

if [ $? -ne 0 ]; then
  echo "[ERROR] Failed to download AI blocklist" | logger -t ai-hosts
  exit 1
fi

# Remove old AI blocklist entries from hosts file
sed -i "/$MARKER_START/,/$MARKER_END/d" "$HOSTS_FILE"

# Append new entries with markers
{
  echo "$MARKER_START"
  echo "# Updated: $(date -u +%Y-%m-%dT%H:%M:%SZ)"
  echo "# Source: aitoolsblocklist.com"
  cat /tmp/ai-hosts-block.txt
  echo "$MARKER_END"
} >> "$HOSTS_FILE"

# Flush DNS cache (macOS)
if [ "$(uname)" = "Darwin" ]; then
  dscacheutil -flushcache
  killall -HUP mDNSResponder 2>/dev/null
fi

COUNT=$(grep -c "^0.0.0.0" /tmp/ai-hosts-block.txt)
echo "[OK] AI hosts blocklist updated: $COUNT domains" | logger -t ai-hosts
rm /tmp/ai-hosts-block.txt

# Update-AIHostsBlocklist.ps1
# Run as Scheduled Task: Daily at 04:00, Run as SYSTEM

$ApiKey      = "YOUR_API_KEY"
$HostsPath   = "C:\Windows\System32\drivers\etc\hosts"
$BackupDir   = "C:\ProgramData\AIBlocklist\backups"
$MarkerStart = "# === AI TOOLS BLOCKLIST START ==="
$MarkerEnd   = "# === AI TOOLS BLOCKLIST END ==="

# Create backup
New-Item -ItemType Directory -Force -Path $BackupDir | Out-Null
Copy-Item $HostsPath "$BackupDir\hosts_$(Get-Date -Format yyyyMMdd).bak"

# Download latest AI domains
$Headers = @{ Authorization = "Bearer $ApiKey" }
try {
    $Response = Invoke-RestMethod `
        -Uri "https://api.aitoolsblocklist.com/v1/feed?format=hosts" `
        -Headers $Headers
} catch {
    Write-EventLog -LogName Application -Source "AIBlocklist" `
        -EventId 1001 -Message "Failed to download AI blocklist: $_"
    exit 1
}

# Read current hosts file, strip old AI entries
$Lines = Get-Content $HostsPath
$InBlock = $false
$Clean  = $Lines | Where-Object {
    if ($_ -eq $MarkerStart) { $InBlock = $true;  return $false }
    if ($_ -eq $MarkerEnd)   { $InBlock = $false; return $false }
    -not $InBlock
}

# Append new AI blocklist
$NewBlock = @(
    $MarkerStart
    "# Updated: $(Get-Date -Format o)"
    "# Source: aitoolsblocklist.com"
    $Response
    $MarkerEnd
)
$Clean + $NewBlock | Set-Content -Path $HostsPath -Encoding ASCII

# Flush DNS cache
ipconfig /flushdns | Out-Null

$Count = ($Response -split "`n" | Where-Object { $_ -match "^0\.0\.0\.0" }).Count
Write-EventLog -LogName Application -Source "AIBlocklist" `
    -EventId 1000 -Message "AI hosts blocklist updated: $Count domains"