diff --git a/scripts/publish_test_metrics.py b/scripts/publish_test_metrics.py
index 82bc9c5..e49223a 100755
--- a/scripts/publish_test_metrics.py
+++ b/scripts/publish_test_metrics.py
@@ -9,6 +9,8 @@ Outputs pushed:
 - platform_quality_gate_runs_total{suite="pegasus",status="ok|failed"}
 - pegasus_quality_gate_tests_total{suite="pegasus",result=*}
 - pegasus_quality_gate_coverage_percent{suite="pegasus"}
+- platform_quality_gate_workspace_line_coverage_percent{suite="pegasus"}
+- platform_quality_gate_source_lines_over_500_total{suite="pegasus"}
 """
 
 from __future__ import annotations
@@ -19,6 +21,9 @@ import urllib.request
 import xml.etree.ElementTree as ET
 from pathlib import Path
 
+SOURCE_SCAN_ROOTS = ("backend", "frontend/src", "scripts", "testing")
+SOURCE_EXTENSIONS = {".go", ".py", ".ts", ".tsx", ".sh"}
+
 
 def _escape_label(value: str) -> str:
     return value.replace("\\", "\\\\").replace("\n", "\\n").replace('"', '\\"')
@@ -146,7 +151,25 @@ def _post_text(url: str, payload: str) -> None:
             raise RuntimeError(f"push failed status={resp.status}")
 
 
+def _count_source_files_over_limit(repo_root: Path, max_lines: int = 500) -> int:
+    count = 0
+    for rel_root in SOURCE_SCAN_ROOTS:
+        base = repo_root / rel_root
+        if not base.exists():
+            continue
+        for path in base.rglob("*"):
+            if not path.is_file():
+                continue
+            if path.suffix not in SOURCE_EXTENSIONS:
+                continue
+            lines = len(path.read_text(encoding="utf-8", errors="ignore").splitlines())
+            if lines > max_lines:
+                count += 1
+    return count
+
+
 def main() -> int:
+    repo_root = Path(__file__).resolve().parents[1]
     suite = os.getenv("SUITE_NAME", "pegasus")
     pushgateway_url = os.getenv(
         "PUSHGATEWAY_URL", "http://platform-quality-gateway.monitoring.svc.cluster.local:9091"
@@ -192,6 +215,7 @@ def main() -> int:
     }
     gate_ok = bool(gate_summary.get("ok"))
     gate_issues = gate_summary.get("issues") or []
+    source_lines_over_500 = _count_source_files_over_limit(repo_root, max_lines=500)
     outcome = (
         "ok"
         if gate_ok
@@ -234,6 +258,10 @@ def main() -> int:
         f'pegasus_quality_gate_tests_total{{suite="{suite}",result="skipped"}} {totals["skipped"]}',
         "# TYPE pegasus_quality_gate_coverage_percent gauge",
         f'pegasus_quality_gate_coverage_percent{{suite="{suite}"}} {coverage_pct:.3f}',
+        "# TYPE platform_quality_gate_workspace_line_coverage_percent gauge",
+        f'platform_quality_gate_workspace_line_coverage_percent{{suite="{suite}"}} {coverage_pct:.3f}',
+        "# TYPE platform_quality_gate_source_lines_over_500_total gauge",
+        f'platform_quality_gate_source_lines_over_500_total{{suite="{suite}"}} {source_lines_over_500}',
         "# TYPE pegasus_quality_gate_status gauge",
         f'pegasus_quality_gate_status{{suite="{suite}",result="{"ok" if gate_ok else "failed"}"}} 1',
         "# TYPE pegasus_quality_gate_issues_total gauge",
@@ -254,6 +282,7 @@ def main() -> int:
         "tests_errors": totals["errors"],
         "tests_skipped": totals["skipped"],
         "coverage_percent": round(coverage_pct, 3),
+        "source_lines_over_500": source_lines_over_500,
         "outcome": outcome,
         "backend_rc": backend_rc,
         "frontend_rc": frontend_rc,