diff --git a/backend/tools/review_structured_acceptance_gate.py b/backend/tools/review_structured_acceptance_gate.py
index 0095a689..bb189783 100644
--- a/backend/tools/review_structured_acceptance_gate.py
+++ b/backend/tools/review_structured_acceptance_gate.py
@@ -911,17 +911,19 @@ def build_trend_rows(
     return trend_rows
 
 
-def load_previous_snapshot() -> Optional[Dict[str, object]]:
-    latest_path = BASELINE_ROOT / "latest-summary.json"
+def load_previous_snapshot(baseline_root: Path = BASELINE_ROOT) -> Optional[Dict[str, object]]:
+    latest_path = baseline_root / "latest-summary.json"
     if not latest_path.exists():
         return None
     return json.loads(latest_path.read_text(encoding="utf-8"))
 
 
-def persist_baseline_history(summary: Dict[str, object]) -> None:
-    BASELINE_ROOT.mkdir(parents=True, exist_ok=True)
-    BASELINE_SNAPSHOTS_DIR.mkdir(parents=True, exist_ok=True)
-    previous_snapshot = load_previous_snapshot()
+def persist_baseline_history(summary: Dict[str, object], baseline_root: Path = BASELINE_ROOT) -> None:
+    snapshots_dir = baseline_root / "snapshots"
+    history_jsonl = baseline_root / "review-structured-baseline-history.jsonl"
+    baseline_root.mkdir(parents=True, exist_ok=True)
+    snapshots_dir.mkdir(parents=True, exist_ok=True)
+    previous_snapshot = load_previous_snapshot(baseline_root)
     generated_at = str(summary["generated_at"])
     safe_stamp = generated_at.replace(":", "-").replace(".", "-")
 
@@ -937,7 +939,7 @@ def persist_baseline_history(summary: Dict[str, object]) -> None:
         "sample_inventory": summary.get("sample_inventory") or [],
     }
 
-    snapshot_path = BASELINE_SNAPSHOTS_DIR / f"{safe_stamp}-review-structured-baseline-snapshot.json"
+    snapshot_path = snapshots_dir / f"{safe_stamp}-review-structured-baseline-snapshot.json"
     snapshot_path.write_text(json.dumps(snapshot_payload, ensure_ascii=False, indent=2), encoding="utf-8")
 
     history_row = {
@@ -948,18 +950,18 @@ def persist_baseline_history(summary: Dict[str, object]) -> None:
         "field_metric_count": len(summary.get("field_baseline") or []),
         "relationship_metric_count": len(summary.get("relationship_baseline") or []),
     }
-    with BASELINE_HISTORY_JSONL.open("a", encoding="utf-8") as fh:
+    with history_jsonl.open("a", encoding="utf-8") as fh:
         fh.write(json.dumps(history_row, ensure_ascii=False) + "\n")
 
-    latest_path = BASELINE_ROOT / "latest-summary.json"
+    latest_path = baseline_root / "latest-summary.json"
     latest_path.write_text(json.dumps(snapshot_payload, ensure_ascii=False, indent=2), encoding="utf-8")
 
-    write_csv(BASELINE_ROOT / "latest-field-baseline.csv", summary.get("field_baseline") or [])
-    write_csv(BASELINE_ROOT / "latest-relationship-baseline.csv", summary.get("relationship_baseline") or [])
-    write_csv(BASELINE_ROOT / "latest-field-baseline-by-contract.csv", summary.get("field_baseline_by_contract") or [])
-    write_csv(BASELINE_ROOT / "latest-field-baseline-by-batch.csv", summary.get("field_baseline_by_batch") or [])
-    write_csv(BASELINE_ROOT / "latest-relationship-baseline-by-type.csv", summary.get("relationship_baseline_by_type") or [])
-    write_csv(BASELINE_ROOT / "latest-sample-inventory.csv", summary.get("sample_inventory") or [])
+    write_csv(baseline_root / "latest-field-baseline.csv", summary.get("field_baseline") or [])
+    write_csv(baseline_root / "latest-relationship-baseline.csv", summary.get("relationship_baseline") or [])
+    write_csv(baseline_root / "latest-field-baseline-by-contract.csv", summary.get("field_baseline_by_contract") or [])
+    write_csv(baseline_root / "latest-field-baseline-by-batch.csv", summary.get("field_baseline_by_batch") or [])
+    write_csv(baseline_root / "latest-relationship-baseline-by-type.csv", summary.get("relationship_baseline_by_type") or [])
+    write_csv(baseline_root / "latest-sample-inventory.csv", summary.get("sample_inventory") or [])
 
     field_trend_rows = build_trend_rows(
         summary.get("field_baseline") or [],
@@ -992,11 +994,11 @@ def persist_baseline_history(summary: Dict[str, object]) -> None:
         ["presence_accuracy", "confidence_accuracy"],
     )
 
-    write_csv(BASELINE_ROOT / "baseline-trend-overall.csv", field_trend_rows)
-    write_csv(BASELINE_ROOT / "baseline-trend-relationship-overall.csv", relationship_trend_rows)
-    write_csv(BASELINE_ROOT / "baseline-trend-by-contract.csv", contract_trend_rows)
-    write_csv(BASELINE_ROOT / "baseline-trend-by-batch.csv", batch_trend_rows)
-    write_csv(BASELINE_ROOT / "baseline-trend-by-relationship-type.csv", relationship_type_trend_rows)
+    write_csv(baseline_root / "baseline-trend-overall.csv", field_trend_rows)
+    write_csv(baseline_root / "baseline-trend-relationship-overall.csv", relationship_trend_rows)
+    write_csv(baseline_root / "baseline-trend-by-contract.csv", contract_trend_rows)
+    write_csv(baseline_root / "baseline-trend-by-batch.csv", batch_trend_rows)
+    write_csv(baseline_root / "baseline-trend-by-relationship-type.csv", relationship_type_trend_rows)
     dashboard_html = build_dashboard_html(
         summary,
         summary.get("field_baseline") or [],
@@ -1005,9 +1007,9 @@ def persist_baseline_history(summary: Dict[str, object]) -> None:
         summary.get("field_baseline_by_batch") or [],
         summary.get("relationship_baseline_by_type") or [],
     )
-    (BASELINE_ROOT / "baseline-trend-dashboard.html").write_text(dashboard_html, encoding="utf-8")
+    (baseline_root / "baseline-trend-dashboard.html").write_text(dashboard_html, encoding="utf-8")
 
-    trend_summary_md = BASELINE_ROOT / "baseline-trend-summary.md"
+    trend_summary_md = baseline_root / "baseline-trend-summary.md"
     lines = [
         "# Structured Baseline Trend Summary",
         "",
@@ -1088,9 +1090,11 @@ def main() -> int:
     parser.add_argument("--api-base", required=True)
     parser.add_argument("--artifact-dir", required=True)
     parser.add_argument("--password", default="123456")
+    parser.add_argument("--baseline-root", default=str(BASELINE_ROOT))
     args = parser.parse_args()
 
     artifact_dir = Path(args.artifact_dir)
+    baseline_root = Path(args.baseline_root)
     summary = run_gate(api_base=args.api_base.rstrip("/"), artifact_dir=artifact_dir, password=args.password)
     summary_path = artifact_dir / "review-structured-acceptance-summary.json"
     summary_path.write_text(json.dumps(summary, ensure_ascii=False, indent=2), encoding="utf-8")
@@ -1124,7 +1128,7 @@ def main() -> int:
         ),
         encoding="utf-8",
     )
-    persist_baseline_history(summary)
+    persist_baseline_history(summary, baseline_root=baseline_root)
     print(f"REVIEW_STRUCTURED_ACCEPTANCE_{summary['status']} {artifact_dir}")
     return 0 if summary["status"] == "PASS" else 1
 
diff --git a/scripts/run-review-structured-acceptance-gate.ps1 b/scripts/run-review-structured-acceptance-gate.ps1
index 4d68abe8..ec9ac60f 100644
--- a/scripts/run-review-structured-acceptance-gate.ps1
+++ b/scripts/run-review-structured-acceptance-gate.ps1
@@ -66,7 +66,8 @@ if ($gitStatus) {
 $failed = @($checks | Where-Object { $_.required -and $_.status -eq "FAIL" })
 if ($failed.Count -eq 0) {
   $logPath = Join-Path $artifactDir "review-structured-acceptance-gate.log"
-  & $pythonPath $toolPath --api-base $ApiUrl --artifact-dir $artifactDir --password $Password 2>&1 | Tee-Object -FilePath $logPath
+  $baselineRoot = Join-Path $artifactDir "baselines"
+  & $pythonPath $toolPath --api-base $ApiUrl --artifact-dir $artifactDir --password $Password --baseline-root $baselineRoot 2>&1 | Tee-Object -FilePath $logPath
   if ($LASTEXITCODE -eq 0) {
     Add-Check -Label "structured acceptance gate" -Status "PASS" -Detail "Structured acceptance gate passed"
   } else {