diff --git a/milestones/README.md b/milestones/README.md
index 36a9737..9114321 100644
--- a/milestones/README.md
+++ b/milestones/README.md
@@ -5,10 +5,13 @@ repositories that install `docgen` and maintain their own demo bundle. The
 library no longer ships an in-repo dogfood; consumers are the integration test
 of record.
 
-**Active:** **[wizard-json-parse.md](wizard-json-parse.md)** —
-wizard JSON bodies must parse; garbage JSON must not look like `{}`.
+**Active:** **[wizard-path-ref.md](wizard-path-ref.md)** —
+wizard `open-bundle` `path` and `tool/update` `ref` must be JSON strings.
 
 **Shipped:**
+- **[wizard-json-parse.md](wizard-json-parse.md)** —
+  wizard JSON bodies must parse; garbage JSON must not look like `{}`
+  (#132).
 - **[wizard-source-paths.md](wizard-source-paths.md)** —
   wizard `source_paths` must be a string array; prose fields must be strings
   (#131).
diff --git a/milestones/wizard-json-parse.md b/milestones/wizard-json-parse.md
index d7ceb08..8e74ce3 100644
--- a/milestones/wizard-json-parse.md
+++ b/milestones/wizard-json-parse.md
@@ -1,7 +1,7 @@
 # Milestone: wizard JSON bodies must parse
 
-**Status:** Active  
-**PR:** (pending)  
+**Status:** Shipped  
+**PR:** [#132](https://github.com/jmjava/documentation-generator/pull/132)  
 **Depends on:** `milestones/wizard-source-paths.md` (PR #131)
 
 ## Problem
@@ -20,12 +20,12 @@ Empty / whitespace-only bodies stay ``{}``. Invalid JSON raises
 
 ## Done when
 
-- [ ] Invalid JSON POST returns 400 and does not write state
-- [ ] JSON ``null`` returns 400
-- [ ] Empty body still succeeds as ``{}``
-- [ ] `ruff check src/ tests/`
-- [ ] `pytest tests/`
-- [ ] `docgen benchmark` (no clock change; meets baseline)
+- [x] Invalid JSON POST returns 400 and does not write state
+- [x] JSON ``null`` returns 400
+- [x] Empty body still succeeds as ``{}``
+- [x] `ruff check src/ tests/`
+- [x] `pytest tests/` (758 passed, 1 skipped)
+- [x] `docgen benchmark` (no clock change; meets baseline)
 
 ## Out of scope
 
diff --git a/milestones/wizard-path-ref.md b/milestones/wizard-path-ref.md
new file mode 100644
index 0000000..0871bad
--- /dev/null
+++ b/milestones/wizard-path-ref.md
@@ -0,0 +1,35 @@
+# Milestone: wizard open-bundle path and tool/update ref must be strings
+
+**Status:** Active  
+**PR:** [#133](https://github.com/jmjava/documentation-generator/pull/133)  
+**Depends on:** `milestones/wizard-json-parse.md` (PR #132)
+
+## Problem
+
+PR #131 typed wizard prose fields and ``source_paths``. ``POST /api/open-bundle``
+and ``POST /api/tool/update`` still used ``str(data.get(...) or default)``.
+
+``path: ["/tmp/bundle"]`` became ``"['/tmp/bundle']"`` and looked like a
+missing yaml file. ``ref: true`` became ``"True"``, which matches the git-ref
+allowlist and would ``pip install`` from that ref. ``ref: 0`` / ``ref: false``
+are falsy, so they silently fell through to ``"main"``.
+
+## Goal
+
+``path`` and ``ref`` must be JSON strings when present. Missing / null ``path``
+still means empty (existing ``path is required``). Missing / null ``ref`` still
+defaults to ``main``. Empty ``ref`` still defaults to ``main``.
+
+## Done when
+
+- [x] List / bool / number ``path`` returns 400
+- [x] Bool / number / list ``ref`` returns 400 (does not pip-install)
+- [x] Missing ``ref`` still defaults to ``main``
+- [x] `ruff check src/ tests/`
+- [x] `pytest tests/` (760 passed, 1 skipped)
+- [x] `docgen benchmark` (no clock change; meets baseline)
+
+## Out of scope
+
+- Wizard ``except Exception`` around ``narration_topic_label``
+- Focus ``paths`` missing vs empty (already typed as a list of strings)
diff --git a/src/docgen/wizard.py b/src/docgen/wizard.py
index f1d05b9..ec1babe 100644
--- a/src/docgen/wizard.py
+++ b/src/docgen/wizard.py
@@ -540,10 +540,11 @@ def api_session():
     def api_open_bundle():
         try:
             data = request_json_object()
+            path = require_json_string(data, "path", default="") or ""
         except WizardError as exc:
             return jsonify({"error": str(exc)}), 400
         try:
-            cfg = open_bundle_config(str(data.get("path") or ""))
+            cfg = open_bundle_config(path)
         except ValueError as exc:
             return jsonify({"ok": False, "error": str(exc)}), 400
         app.config["DOCGEN"] = cfg
@@ -582,9 +583,9 @@ def api_tool_update():
             data = request_json_object()
             with_manim = require_json_bool(data, "with_manim", default=False)
             update_req = require_json_bool(data, "update_requirements", default=True)
+            ref = require_json_string(data, "ref", default="main") or "main"
         except WizardError as exc:
             return jsonify({"error": str(exc)}), 400
-        ref = str(data.get("ref") or "main")
         bundle = cfg.base_dir if cfg else None
         try:
             result = update_docgen_install(
diff --git a/tests/test_gui_packaging.py b/tests/test_gui_packaging.py
index 013279a..f93d741 100644
--- a/tests/test_gui_packaging.py
+++ b/tests/test_gui_packaging.py
@@ -197,6 +197,9 @@ def test_session_and_open_bundle(tmp_path: Path) -> None:
     assert missing.status_code == 400
     empty = client.post("/api/open-bundle", json={"path": ""})
     assert empty.status_code == 400
+    listed = client.post("/api/open-bundle", json={"path": [str(tmp_path)]})
+    assert listed.status_code == 400
+    assert "path must be a JSON string" in listed.get_json()["error"]
 
 
 def test_open_bundle_config_helper(tmp_path: Path) -> None:
diff --git a/tests/test_install_spec.py b/tests/test_install_spec.py
index 2aba6b3..e70a0bc 100644
--- a/tests/test_install_spec.py
+++ b/tests/test_install_spec.py
@@ -133,8 +133,19 @@ class _Proc:
     assert data["restart_required"] is True
     assert read_requirements_pin(tmp_path / "requirements-docgen.txt") == "main"
 
+    with patch("docgen.install_spec.subprocess.run", return_value=_Proc()):
+        missing_ref = client.post(
+            "/api/tool/update",
+            json={"update_requirements": True, "with_manim": False},
+        )
+    assert missing_ref.status_code == 200, missing_ref.get_json()
+    assert missing_ref.get_json()["ref"] == "main"
+
     bad = client.post("/api/tool/update", json={"ref": "main;id"})
     assert bad.status_code == 400
+    typed = client.post("/api/tool/update", json={"ref": True})
+    assert typed.status_code == 400
+    assert "ref must be a JSON string" in typed.get_json()["error"]
 
 
 def test_tool_info_without_requirements(tmp_path: Path) -> None:
diff --git a/tests/test_wizard.py b/tests/test_wizard.py
index d6a999d..eaed29a 100644
--- a/tests/test_wizard.py
+++ b/tests/test_wizard.py
@@ -210,6 +210,21 @@ def test_api_tool_update_rejects_string_with_manim(tmp_path):
     assert "with_manim must be a JSON boolean" in res.get_json()["error"]
 
 
+def test_api_open_bundle_rejects_non_string_path(tmp_path):
+    client, _cfg = _wizard_client(tmp_path)
+    res = client.post("/api/open-bundle", json={"path": [str(tmp_path)]})
+    assert res.status_code == 400
+    assert "path must be a JSON string" in res.get_json()["error"]
+
+
+def test_api_tool_update_rejects_non_string_ref(tmp_path):
+    client, _cfg = _wizard_client(tmp_path)
+    for payload in ({"ref": True}, {"ref": 0}, {"ref": False}, {"ref": ["main"]}):
+        res = client.post("/api/tool/update", json=payload)
+        assert res.status_code == 400, payload
+        assert "ref must be a JSON string" in res.get_json()["error"]
+
+
 def test_api_run_from_rejects_string_llm_scene_spec(tmp_path):
     client, _cfg = _wizard_client(tmp_path)
     res = client.post("/api/run-from/tts/01", json={"llm_scene_spec": "true"})