diff --git a/src/patchorder/cli.py b/src/patchorder/cli.py
index 0a45108..b5d9430 100644
--- a/src/patchorder/cli.py
+++ b/src/patchorder/cli.py
@@ -81,6 +81,7 @@ def _parser() -> argparse.ArgumentParser:
     inv_check.add_argument("inventory", type=Path)
     inv_check.add_argument("-l", "--lock", type=Path, help="lock file (default: next to the inventory)")
     inv_check.add_argument("--strict", action="store_true", help="exit 4 on warnings too")
+    inv_check.add_argument("--json", action="store_true", help="emit notes as JSON array (level, asset_id, text)")
     inv_check.set_defaults(func=cmd_inventory_check)
     inv_csv = inv_sub.add_parser("from-csv", help="turn a CSV export into inventory YAML (printed unless --output)")
     inv_csv.add_argument("csv", type=Path)
@@ -353,9 +354,17 @@ def _maybe_llm(args, report) -> None:
 
 
 def cmd_inventory_check(args: argparse.Namespace) -> int:
-    from patchorder.inventorytools import check_inventory
+    from patchorder.inventorytools import check_inventory, notes_to_json
 
     notes = check_inventory(args.inventory, args.lock)
+    if args.json:
+        print(notes_to_json(notes))
+        counts = {"error": 0, "warning": 0, "info": 0}
+        for note in notes:
+            counts[note.level] += 1
+        if args.strict and counts["warning"]:
+            return 4
+        return 0
     counts = {"error": 0, "warning": 0, "info": 0}
     for note in notes:
         counts[note.level] += 1
diff --git a/src/patchorder/inventorytools.py b/src/patchorder/inventorytools.py
index 9469a3b..da06c0b 100644
--- a/src/patchorder/inventorytools.py
+++ b/src/patchorder/inventorytools.py
@@ -5,7 +5,7 @@
 import csv
 import io
 import json
-from dataclasses import dataclass
+from dataclasses import asdict, dataclass
 from pathlib import Path
 
 
@@ -67,6 +67,11 @@ def check_inventory(path: Path, lock_path: Path | None = None) -> list[Inventory
     return notes
 
 
+def notes_to_json(notes: list[InventoryNote]) -> str:
+    """Serialize inventory notes as a JSON array with stable key order."""
+    return json.dumps([asdict(note) for note in notes], ensure_ascii=False, separators=(",", ":"))
+
+
 def _normalize_header(name: str) -> str:
     key = name.strip().lower().replace(" ", "_")
     return _HEADER_ALIASES.get(key, key)
diff --git a/tests/test_v02_gate_csv_inventory.py b/tests/test_v02_gate_csv_inventory.py
index 763082a..b5cce52 100644
--- a/tests/test_v02_gate_csv_inventory.py
+++ b/tests/test_v02_gate_csv_inventory.py
@@ -147,3 +147,70 @@ def test_cli_from_csv_writes_only_with_output(tmp_path, capsys):
     out = tmp_path / "inventory.yaml"
     assert main(["inventory", "from-csv", str(src), "--output", str(out)]) == 0
     assert load_inventory(out).assets[0].version == "1.27.2"
+
+
+def test_inventory_check_json_empty(tmp_path, capsys):
+    inv = tmp_path / "inv.yaml"
+    inv.write_text(
+        "schema: patchorder.inventory/v1\nname: t\nassets:\n"
+        "  - {id: a, product: nginx, version: \"1.25.2\", count: 1, owner: o, exposure: internal}\n",
+        encoding="utf-8",
+    )
+    (tmp_path / "inv.lock.yaml").write_text(
+        "schema: patchorder.lock/v1\nentries:\n  a:\n    cpe: cpe:2.3:a:f5:nginx\n    pinned: true\n    origin: user\n",
+        encoding="utf-8",
+    )
+    assert main(["inventory", "check", str(inv), "--json"]) == 0
+    out = capsys.readouterr().out.strip()
+    assert out == "[]"
+
+
+def test_inventory_check_json_with_notes(tmp_path, capsys):
+    inv = tmp_path / "inv.yaml"
+    inv.write_text(
+        "schema: patchorder.inventory/v1\nname: t\nassets:\n"
+        "  - {id: a, product: Example Thing, version: \"1.0\", count: 0, owner: o, exposure: internal}\n"
+        "  - {id: b, product: Example Thing, version: \"1.0\", count: 2, owner: o, exposure: internal}\n",
+        encoding="utf-8",
+    )
+    (tmp_path / "inv.lock.yaml").write_text(
+        "schema: patchorder.lock/v1\nentries:\n  gone:\n    cpe: cpe:2.3:a:example:thing\n    pinned: true\n    origin: user\n",
+        encoding="utf-8",
+    )
+    assert main(["inventory", "check", str(inv), "--json"]) == 0
+    out = capsys.readouterr().out.strip()
+    import json as jsonlib
+
+    notes = jsonlib.loads(out)
+    assert isinstance(notes, list)
+    assert len(notes) == 5
+    for note in notes:
+        assert set(note.keys()) == {"level", "asset_id", "text"}
+    levels = [n["level"] for n in notes]
+    assert "warning" in levels
+    assert "info" in levels
+
+
+def test_inventory_check_strict_json_exit_code(tmp_path, capsys):
+    inv = tmp_path / "inv.yaml"
+    inv.write_text(
+        "schema: patchorder.inventory/v1\nname: t\nassets:\n"
+        "  - {id: a, product: nginx, version: \"1.25.2\", count: 1, owner: o, exposure: internal}\n",
+        encoding="utf-8",
+    )
+    (tmp_path / "inv.lock.yaml").write_text(
+        "schema: patchorder.lock/v1\nentries:\n  a:\n    cpe: cpe:2.3:a:f5:nginx\n    pinned: true\n    origin: user\n",
+        encoding="utf-8",
+    )
+    assert main(["inventory", "check", str(inv), "--json", "--strict"]) == 0
+    inv.write_text(
+        "schema: patchorder.inventory/v1\nname: t\nassets:\n"
+        "  - {id: a, product: Example Thing, version: \"1.0\", count: 0, owner: o, exposure: internal}\n"
+        "  - {id: b, product: Example Thing, version: \"1.0\", count: 2, owner: o, exposure: internal}\n",
+        encoding="utf-8",
+    )
+    (tmp_path / "inv.lock.yaml").write_text(
+        "schema: patchorder.lock/v1\nentries:\n  gone:\n    cpe: cpe:2.3:a:example:thing\n    pinned: true\n    origin: user\n",
+        encoding="utf-8",
+    )
+    assert main(["inventory", "check", str(inv), "--json", "--strict"]) == 4