diff --git a/.github/scripts/check_spec_coverage.py b/.github/scripts/check_spec_coverage.py
new file mode 100644
index 0000000..a60132c
--- /dev/null
+++ b/.github/scripts/check_spec_coverage.py
@@ -0,0 +1,57 @@
+#!/usr/bin/env python3
+"""Map a spec-diff to affected docs.pinecone.io pages + impacted SDKs via the manifest.
+
+Reads spec-diff.json (from extract_spec_diff.py) and spec-manifest.json, joins on
+operation id / schema name, and writes spec-gaps.json. Changed surface absent from
+the manifest is logged to spec-gaps-unmapped.json so the manifest can be kept current.
+Sets the `has_gaps` GitHub Actions output.
+"""
+import argparse
+import json
+import os
+from pathlib import Path
+
+
+def main():
+    ap = argparse.ArgumentParser()
+    ap.add_argument("--spec-diff", required=True)
+    ap.add_argument("--manifest", required=True)
+    ap.add_argument("--output", default="spec-gaps.json")
+    a = ap.parse_args()
+
+    diff = json.loads(Path(a.spec_diff).read_text())
+    man = json.loads(Path(a.manifest).read_text())
+    ops = man.get("operations", {})
+    schs = man.get("schemas", {})
+
+    gaps, unmapped = [], []
+    for c in diff:
+        if c["kind"] == "operation":
+            entry = ops.get(c["id"])
+        else:
+            # schema ids may be "Schema" or "Schema.property" — map by schema name
+            entry = schs.get(c["id"].split(".")[0])
+        if not entry:
+            unmapped.append(c)
+            continue
+        for page in entry.get("docs", []):
+            gaps.append({
+                "symbol": c["id"], "change": c["change"], "breaking": c.get("breaking", False),
+                "doc_page": page, "sdks": entry.get("sdks", []), "detail": c.get("detail", ""),
+            })
+
+    Path(a.output).write_text(json.dumps(gaps, indent=2))
+    if unmapped:
+        Path("spec-gaps-unmapped.json").write_text(json.dumps(unmapped, indent=2))
+
+    has_gaps = bool(gaps)
+    gh = os.environ.get("GITHUB_OUTPUT")
+    if gh:
+        with open(gh, "a") as f:
+            f.write(f"has_gaps={'true' if has_gaps else 'false'}\n")
+    pages = len({g["doc_page"] for g in gaps})
+    print(f"{len(gaps)} doc-gaps across {pages} page(s); {len(unmapped)} unmapped")
+
+
+if __name__ == "__main__":
+    main()
diff --git a/.github/scripts/tests/test_check_spec_coverage.py b/.github/scripts/tests/test_check_spec_coverage.py
new file mode 100644
index 0000000..c5d6063
--- /dev/null
+++ b/.github/scripts/tests/test_check_spec_coverage.py
@@ -0,0 +1,31 @@
+"""Unit test for check_spec_coverage. Run: pytest .github/scripts/tests -v"""
+import json
+import os
+import subprocess
+import sys
+
+
+def test_maps_to_docs_and_sdks_and_unmapped(tmp_path):
+    diff = [
+        {"kind": "operation", "id": "create_index", "change": "modified", "breaking": True, "detail": "x"},
+        {"kind": "schema", "id": "Index.host", "change": "added", "breaking": False, "detail": "y"},
+        {"kind": "operation", "id": "unknown_op", "change": "added", "breaking": False, "detail": "z"},
+    ]
+    man = {"operations": {"create_index": {"docs": ["guides/index-data/create-an-index"], "sdks": ["python", "ts"]}},
+           "schemas": {"Index": {"docs": ["guides/index-data/indexes"], "sdks": ["python"]}}}
+    dp = tmp_path / "diff.json"
+    mp = tmp_path / "man.json"
+    op = tmp_path / "gaps.json"
+    dp.write_text(json.dumps(diff))
+    mp.write_text(json.dumps(man))
+    script = os.path.join(os.path.dirname(__file__), "..", "check_spec_coverage.py")
+    r = subprocess.run([sys.executable, script, "--spec-diff", str(dp),
+                        "--manifest", str(mp), "--output", str(op)],
+                       capture_output=True, text=True, cwd=str(tmp_path))
+    assert r.returncode == 0, r.stderr
+    gaps = json.loads(op.read_text())
+    pages = {g["doc_page"] for g in gaps}
+    assert "guides/index-data/create-an-index" in pages
+    assert "guides/index-data/indexes" in pages  # schema property mapped via "Index"
+    assert any(g["breaking"] for g in gaps)
+    assert all(g["symbol"] != "unknown_op" for g in gaps)  # unmapped, not in gaps