diff --git a/.github/workflows/guardrail-gate-nightly.yml b/.github/workflows/guardrail-gate-nightly.yml
new file mode 100644
index 0000000..fc4efdc
--- /dev/null
+++ b/.github/workflows/guardrail-gate-nightly.yml
@@ -0,0 +1,79 @@
+name: Guardrail Gate (Nightly Drift Check)
+
+on:
+  schedule:
+    - cron: "17 3 * * *"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  guardrail-nightly:
+    name: Guardrail Gate Nightly
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install PowerShell (Ubuntu)
+        if: matrix.os == 'ubuntu-latest'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y wget apt-transport-https software-properties-common
+          wget -q https://packages.microsoft.com/config/ubuntu/22.04/packages-microsoft-prod.deb
+          sudo dpkg -i packages-microsoft-prod.deb
+          sudo apt-get update
+          sudo apt-get install -y powershell
+
+      - name: Generate lane artifacts
+        shell: pwsh
+        run: |
+          pwsh scripts/lanes/check-infra.ps1
+          pwsh scripts/lanes/check-sec.ps1
+          pwsh scripts/lanes/check-web-build.ps1
+          pwsh scripts/lanes/check-data.ps1
+          pwsh scripts/lanes/check-obs.ps1
+          pwsh scripts/lanes/check-perf.ps1
+          pwsh scripts/lanes/check-a11y.ps1
+          pwsh scripts/lanes/check-gov.ps1
+
+      - name: Run guardrail enforcer
+        shell: pwsh
+        run: pwsh -File scripts/run-guardrail-enforcer.ps1 -OutDir ai/out
+
+      - name: Append report to job summary
+        if: always()
+        shell: pwsh
+        run: |
+          if (Test-Path "ai/out/GUARDRAIL_ENFORCER_REPORT.md") {
+            $content = Get-Content "ai/out/GUARDRAIL_ENFORCER_REPORT.md" -Raw
+            Write-Host "$content"
+            echo "$content" >> $env:GITHUB_STEP_SUMMARY
+          } else {
+            Write-Host "Report missing"
+          }
+
+      - name: Upload artifacts
+        if: failure() || success()
+        uses: actions/upload-artifact@v4
+        with:
+          name: guardrail-artifacts-nightly-${{ matrix.os }}
+          path: |
+            ai/out/LANE_*.md
+            ai/out/GUARDRAIL_ENFORCER_REPORT.md
+
+      - name: Slack notify on failure (optional)
+        if: failure() && env.SLACK_WEBHOOK_URL != ''
+        uses: slackapi/slack-github-action@v1.24.0
+        with:
+          payload: |
+            {
+              "text": "Nightly Guardrail Gate failed on ${{ matrix.os }} for ${{ github.repository }}@${{ github.ref }}. See artifacts and report."
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+
diff --git a/.github/workflows/guardrail-gate.yml b/.github/workflows/guardrail-gate.yml
new file mode 100644
index 0000000..b93f9e9
--- /dev/null
+++ b/.github/workflows/guardrail-gate.yml
@@ -0,0 +1,80 @@
+name: Guardrail Gate (PR & Push)
+
+on:
+  push:
+    branches: ["**"]
+  pull_request:
+    branches: ["**"]
+
+permissions:
+  contents: read
+
+jobs:
+  guardrail:
+    name: Guardrail Gate
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install PowerShell (Ubuntu)
+        if: matrix.os == 'ubuntu-latest'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y wget apt-transport-https software-properties-common
+          wget -q https://packages.microsoft.com/config/ubuntu/22.04/packages-microsoft-prod.deb
+          sudo dpkg -i packages-microsoft-prod.deb
+          sudo apt-get update
+          sudo apt-get install -y powershell
+
+      - name: Generate lane artifacts
+        shell: pwsh
+        run: |
+          pwsh scripts/lanes/check-infra.ps1
+          pwsh scripts/lanes/check-sec.ps1
+          pwsh scripts/lanes/check-web-build.ps1
+          pwsh scripts/lanes/check-data.ps1
+          pwsh scripts/lanes/check-obs.ps1
+          pwsh scripts/lanes/check-perf.ps1
+          pwsh scripts/lanes/check-a11y.ps1
+          pwsh scripts/lanes/check-gov.ps1
+
+      - name: Run guardrail enforcer
+        shell: pwsh
+        run: pwsh -File scripts/run-guardrail-enforcer.ps1 -OutDir ai/out
+
+      - name: Append report to job summary
+        if: always()
+        shell: pwsh
+        run: |
+          if (Test-Path "ai/out/GUARDRAIL_ENFORCER_REPORT.md") {
+            $content = Get-Content "ai/out/GUARDRAIL_ENFORCER_REPORT.md" -Raw
+            Write-Host "$content"
+            echo "$content" >> $env:GITHUB_STEP_SUMMARY
+          } else {
+            Write-Host "Report missing"
+          }
+
+      - name: Upload artifacts
+        if: failure() || success()
+        uses: actions/upload-artifact@v4
+        with:
+          name: guardrail-artifacts-${{ matrix.os }}
+          path: |
+            ai/out/LANE_*.md
+            ai/out/GUARDRAIL_ENFORCER_REPORT.md
+
+      - name: Slack notify on failure (optional)
+        if: failure() && env.SLACK_WEBHOOK_URL != ''
+        uses: slackapi/slack-github-action@v1.24.0
+        with:
+          payload: |
+            {
+              "text": "Guardrail Gate failed on ${{ matrix.os }} for ${{ github.repository }}@${{ github.ref }}. See artifacts and report."
+            }
+        env:
+          SLACK_WEBHOOK_URL: ${{ secrets.SLACK_WEBHOOK_URL }}
+
diff --git a/ai/out/GUARDRAIL_ENFORCER_REPORT.md b/ai/out/GUARDRAIL_ENFORCER_REPORT.md
new file mode 100644
index 0000000..6e962da
--- /dev/null
+++ b/ai/out/GUARDRAIL_ENFORCER_REPORT.md
@@ -0,0 +1,11 @@
+# Guardrail Enforcer Report
+
+OutDir: ai/out
+Generated: 2025-11-27 20:10:10
+
+Lanes:
+- LANE_INFRA: INFRA_OK
+- LANE_SEC: SEC_OK
+
+
+Decision: RELEASE_GO
diff --git a/ai/out/LANE_INFRA.md b/ai/out/LANE_INFRA.md
new file mode 100644
index 0000000..c86ee0d
--- /dev/null
+++ b/ai/out/LANE_INFRA.md
@@ -0,0 +1,10 @@
+# Lane: INFRA
+Date: 2025-11-27 20:10:09
+
+Summary:
+INFRA baseline OK (placeholder).
+
+Checks:
+- Placeholder pass
+
+Result: INFRA_OK
diff --git a/ai/out/LANE_SEC.md b/ai/out/LANE_SEC.md
new file mode 100644
index 0000000..9eb7287
--- /dev/null
+++ b/ai/out/LANE_SEC.md
@@ -0,0 +1,10 @@
+# Lane: SEC
+Date: 2025-11-27 20:10:10
+
+Summary:
+SEC baseline OK (placeholder).
+
+Checks:
+- Placeholder pass
+
+Result: SEC_OK
diff --git a/docs/guardrail-gate.md b/docs/guardrail-gate.md
new file mode 100644
index 0000000..6617b04
Binary files /dev/null and b/docs/guardrail-gate.md differ
diff --git a/scripts/lanes/_lane-helper.ps1 b/scripts/lanes/_lane-helper.ps1
new file mode 100644
index 0000000..3e7ecac
--- /dev/null
+++ b/scripts/lanes/_lane-helper.ps1
@@ -0,0 +1,17 @@
+function New-Lane {
+  param([Parameter(Mandatory=$true)][string]$Name,[Parameter(Mandatory=$true)][string]$Summary)
+  $lanePath = "ai/out/LANE_{0}.md" -f $Name
+  @"
+# Lane: $Name
+Date: $(Get-Date -Format "yyyy-MM-dd HH:mm:ss")
+
+Summary:
+$Summary
+
+Checks:
+- Placeholder pass
+
+Result: ${Name}_OK
+"@ | Set-Content $lanePath
+}
+
diff --git a/scripts/lanes/check-a11y.ps1 b/scripts/lanes/check-a11y.ps1
new file mode 100644
index 0000000..41270e3
--- /dev/null
+++ b/scripts/lanes/check-a11y.ps1
@@ -0,0 +1,2 @@
+. "$(Join-Path $PSScriptRoot '_lane-helper.ps1')"
+New-Lane -Name "A11Y" -Summary "A11Y baseline OK (placeholder)."
diff --git a/scripts/lanes/check-data.ps1 b/scripts/lanes/check-data.ps1
new file mode 100644
index 0000000..96787a0
--- /dev/null
+++ b/scripts/lanes/check-data.ps1
@@ -0,0 +1,2 @@
+. "$(Join-Path $PSScriptRoot '_lane-helper.ps1')"
+New-Lane -Name "DATA" -Summary "DATA baseline OK (placeholder)."
diff --git a/scripts/lanes/check-gov.ps1 b/scripts/lanes/check-gov.ps1
new file mode 100644
index 0000000..3b062ea
--- /dev/null
+++ b/scripts/lanes/check-gov.ps1
@@ -0,0 +1,2 @@
+. "$(Join-Path $PSScriptRoot '_lane-helper.ps1')"
+New-Lane -Name "GOV" -Summary "GOV baseline OK (placeholder)."
diff --git a/scripts/lanes/check-infra.ps1 b/scripts/lanes/check-infra.ps1
new file mode 100644
index 0000000..2c882b7
--- /dev/null
+++ b/scripts/lanes/check-infra.ps1
@@ -0,0 +1,2 @@
+. "$(Join-Path $PSScriptRoot '_lane-helper.ps1')"
+New-Lane -Name "INFRA" -Summary "INFRA baseline OK (placeholder)."
diff --git a/scripts/lanes/check-obs.ps1 b/scripts/lanes/check-obs.ps1
new file mode 100644
index 0000000..3fc658c
--- /dev/null
+++ b/scripts/lanes/check-obs.ps1
@@ -0,0 +1,2 @@
+. "$(Join-Path $PSScriptRoot '_lane-helper.ps1')"
+New-Lane -Name "OBS" -Summary "OBS baseline OK (placeholder)."
diff --git a/scripts/lanes/check-perf.ps1 b/scripts/lanes/check-perf.ps1
new file mode 100644
index 0000000..c1d2f4a
--- /dev/null
+++ b/scripts/lanes/check-perf.ps1
@@ -0,0 +1,2 @@
+. "$(Join-Path $PSScriptRoot '_lane-helper.ps1')"
+New-Lane -Name "PERF" -Summary "PERF baseline OK (placeholder)."
diff --git a/scripts/lanes/check-sec.ps1 b/scripts/lanes/check-sec.ps1
new file mode 100644
index 0000000..0fd26b0
--- /dev/null
+++ b/scripts/lanes/check-sec.ps1
@@ -0,0 +1,2 @@
+. "$(Join-Path $PSScriptRoot '_lane-helper.ps1')"
+New-Lane -Name "SEC" -Summary "SEC baseline OK (placeholder)."
diff --git a/scripts/lanes/check-web-build.ps1 b/scripts/lanes/check-web-build.ps1
new file mode 100644
index 0000000..13faacb
--- /dev/null
+++ b/scripts/lanes/check-web-build.ps1
@@ -0,0 +1,2 @@
+. "$(Join-Path $PSScriptRoot '_lane-helper.ps1')"
+New-Lane -Name "WEB_BUILD" -Summary "WEB_BUILD baseline OK (placeholder)."
diff --git a/scripts/run-guardrail-enforcer.ps1 b/scripts/run-guardrail-enforcer.ps1
new file mode 100644
index 0000000..f135eff
--- /dev/null
+++ b/scripts/run-guardrail-enforcer.ps1
@@ -0,0 +1,42 @@
+param([string]$OutDir = $env:GUARDRAIL_OUT_DIR)
+
+if (-not $OutDir) { $OutDir = "ai/out" }
+
+$ErrorActionPreference = "Stop"
+
+if (-not (Test-Path $OutDir)) { New-Item -ItemType Directory -Force -Path $OutDir | Out-Null }
+
+$laneFiles = Get-ChildItem -Path $OutDir -Filter "LANE_*.md" -ErrorAction SilentlyContinue
+
+$results = @()
+
+foreach ($file in $laneFiles) {
+  $text = Get-Content $file.FullName -Raw
+  $match = [regex]::Match($text, "(?m)^Result:\s*(\S+)")
+  if ($match.Success) { $results += [PSCustomObject]@{ Lane = $file.BaseName; Result = $match.Groups[1].Value } }
+  else { $results += [PSCustomObject]@{ Lane = $file.BaseName; Result = "UNKNOWN" } }
+}
+
+$overall = "RELEASE_GO"
+
+foreach ($r in $results) { if ($r.Result -notmatch "OK|RELEASE_GO") { $overall = "RELEASE_HOLD"; break } }
+
+$report = @"
+# Guardrail Enforcer Report
+
+OutDir: $OutDir
+Generated: $(Get-Date -Format "yyyy-MM-dd HH:mm:ss")
+
+Lanes:
+$(
+  $results | ForEach-Object { "- $($_.Lane): $($_.Result)" } | Out-String
+)
+
+Decision: $overall
+"@
+
+$reportPath = Join-Path $OutDir "GUARDRAIL_ENFORCER_REPORT.md"
+Set-Content -Path $reportPath -Value $report
+
+if ($overall -eq "RELEASE_GO") { exit 0 } else { Write-Error "Release gated: $overall"; exit 1 }
+