diff --git a/CHANGELOG.md b/CHANGELOG.md
index 363569a..b5a15eb 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,11 @@ All notable changes to this package. Versions follow [Semantic Versioning](https
 
 ## Unreleased
 
+### Data validation
+
+- Validate prefab hierarchy documents against their published transform and component schema.
+- Describe room, spot, sound, video and CRI Lips documents, and accept null localization on native text records.
+
 ### Site products
 
 - Load live variants from entry manifests and accept variant paths in read-set requests.
@@ -179,4 +184,3 @@ All notable changes to this package. Versions follow [Semantic Versioning](https
 - install from GitHub until the package is on npm
 - add performance.md: the CPU cost of a frame
 - a file holds each controller and clip once; the validator checks every reference _(story)_
-
diff --git a/docs/data-format.md b/docs/data-format.md
index 18c5435..75b4be7 100644
--- a/docs/data-format.md
+++ b/docs/data-format.md
@@ -119,6 +119,9 @@ Rules:
 
 ### Objects
 
+Prefab object documents have a [JSON Schema](../schema/prefab.schema.json) for hierarchy nodes, transforms,
+components and RectTransform fields. Data validation also checks that parents precede their children.
+
 Several products may retain different file roles of the same object. Loading their manifests combines these
 roles; overlapping roles and object metadata must agree. Product paths may include region directories, and are
 relative to the layout root.
@@ -988,3 +991,11 @@ The song catalog example reads `music-data.json` with format `nnnotes.music-data
 A chart entry under `charts/` can be an `nnnotes.product/1` live manifest. Its optional `variants` lists immutable note-skin, note-effect and sound products relative to its declared root; the loader combines them with the required parts. `options.LiveQuality` lists the offered qualities. `scripts/read-set.mjs --variants=<JSON array>` supplies extra manifest paths for either plan or full mode.
 
 The live's `parts.ui` maps languages to UI products. An `audio: false` entry omits sound streams while retaining cue metadata. Story sessions use silent timing for such entries. Story listings select a playback language for which the entry includes resources.
+
+### Scene and media document schemas
+
+- [room](../schema/room.schema.json)
+- [spot](../schema/spot.schema.json)
+- [story-video](../schema/story-video.schema.json)
+- [story-sound](../schema/story-sound.schema.json)
+- [crilips](../schema/crilips.schema.json)
diff --git a/schema/crilips.schema.json b/schema/crilips.schema.json
new file mode 100644
index 0000000..badd45a
--- /dev/null
+++ b/schema/crilips.schema.json
@@ -0,0 +1,57 @@
+{
+  "$id": "https://raw.githubusercontent.com/empty-sekai/ournotes-player/main/schema/crilips.schema.json",
+  "title": "crilips document",
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "required": [
+    "dtype",
+    "order",
+    "total_floats",
+    "blocks",
+    "constants",
+    "frontend"
+  ],
+  "properties": {
+    "dtype": {
+      "const": "float32"
+    },
+    "order": {
+      "const": "LE"
+    },
+    "total_floats": {
+      "type": "integer",
+      "minimum": 0
+    },
+    "blocks": {
+      "type": "array",
+      "items": {
+        "$schema": "https://json-schema.org/draft/2020-12/schema",
+        "type": "object",
+        "required": [
+          "name",
+          "offset",
+          "count"
+        ],
+        "properties": {
+          "name": {
+            "type": "string"
+          },
+          "offset": {
+            "type": "integer",
+            "minimum": 0
+          },
+          "count": {
+            "type": "integer",
+            "minimum": 0
+          }
+        }
+      }
+    },
+    "constants": {
+      "type": "object"
+    },
+    "frontend": {
+      "type": "object"
+    }
+  }
+}
diff --git a/schema/prefab.schema.json b/schema/prefab.schema.json
new file mode 100644
index 0000000..5ca948d
--- /dev/null
+++ b/schema/prefab.schema.json
@@ -0,0 +1,174 @@
+{
+  "$id": "https://raw.githubusercontent.com/empty-sekai/ournotes-player/main/schema/prefab.schema.json",
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "required": [
+    "nodes"
+  ],
+  "properties": {
+    "name": {
+      "type": "string"
+    },
+    "scene": {
+      "type": "string"
+    },
+    "nodes": {
+      "type": "array",
+      "items": {
+        "$ref": "#/$defs/node"
+      }
+    }
+  },
+  "$defs": {
+    "vec2": {
+      "type": "object",
+      "required": [
+        "x",
+        "y"
+      ],
+      "properties": {
+        "x": {
+          "type": "number"
+        },
+        "y": {
+          "type": "number"
+        }
+      }
+    },
+    "vec3": {
+      "type": "object",
+      "required": [
+        "x",
+        "y",
+        "z"
+      ],
+      "properties": {
+        "x": {
+          "type": "number"
+        },
+        "y": {
+          "type": "number"
+        },
+        "z": {
+          "type": "number"
+        }
+      }
+    },
+    "quat": {
+      "type": "object",
+      "required": [
+        "x",
+        "y",
+        "z",
+        "w"
+      ],
+      "properties": {
+        "x": {
+          "type": "number"
+        },
+        "y": {
+          "type": "number"
+        },
+        "z": {
+          "type": "number"
+        },
+        "w": {
+          "type": "number"
+        }
+      }
+    },
+    "component": {
+      "type": "object",
+      "required": [
+        "type"
+      ],
+      "properties": {
+        "type": {
+          "type": "string",
+          "minLength": 1
+        },
+        "pathId": {
+          "type": "string",
+          "pattern": "^-?[0-9]+$"
+        },
+        "script": {
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "fields": {
+          "type": "object"
+        }
+      }
+    },
+    "node": {
+      "type": "object",
+      "required": [
+        "path",
+        "localPosition",
+        "localRotation",
+        "localScale",
+        "components"
+      ],
+      "properties": {
+        "path": {
+          "type": "string"
+        },
+        "name": {
+          "type": "string"
+        },
+        "pathId": {
+          "type": "string",
+          "pattern": "^-?[0-9]+$"
+        },
+        "transformPathId": {
+          "type": "string",
+          "pattern": "^-?[0-9]+$"
+        },
+        "active": {
+          "type": "boolean"
+        },
+        "layer": {
+          "type": "integer"
+        },
+        "localPosition": {
+          "$ref": "#/$defs/vec3"
+        },
+        "localRotation": {
+          "$ref": "#/$defs/quat"
+        },
+        "localScale": {
+          "$ref": "#/$defs/vec3"
+        },
+        "components": {
+          "type": "array",
+          "items": {
+            "$ref": "#/$defs/component"
+          }
+        },
+        "rect": {
+          "type": "object",
+          "properties": {
+            "m_AnchorMin": {
+              "$ref": "#/$defs/vec2"
+            },
+            "m_AnchorMax": {
+              "$ref": "#/$defs/vec2"
+            },
+            "m_AnchoredPosition": {
+              "$ref": "#/$defs/vec2"
+            },
+            "m_SizeDelta": {
+              "$ref": "#/$defs/vec2"
+            },
+            "m_Pivot": {
+              "$ref": "#/$defs/vec2"
+            }
+          }
+        }
+      }
+    }
+  },
+  "title": "Prefab hierarchy"
+}
diff --git a/schema/room.schema.json b/schema/room.schema.json
new file mode 100644
index 0000000..5c024a9
--- /dev/null
+++ b/schema/room.schema.json
@@ -0,0 +1,81 @@
+{
+  "$id": "https://raw.githubusercontent.com/empty-sekai/ournotes-player/main/schema/room.schema.json",
+  "title": "room document",
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "required": [
+    "backgroundKey",
+    "glb",
+    "meshCount",
+    "inactiveMeshes",
+    "nodes",
+    "materialIds",
+    "materials",
+    "textures",
+    "samplers"
+  ],
+  "properties": {
+    "backgroundKey": {
+      "type": "string"
+    },
+    "glb": {
+      "type": "string"
+    },
+    "meshCount": {
+      "type": "integer",
+      "minimum": 0
+    },
+    "inactiveMeshes": {
+      "type": "integer",
+      "minimum": 0
+    },
+    "nullMaterialSubmeshes": {
+      "type": "array",
+      "items": {
+        "type": "object"
+      }
+    },
+    "nullMeshFilters": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      }
+    },
+    "emptyMeshes": {
+      "type": "array",
+      "items": {
+        "type": "object"
+      }
+    },
+    "nodes": {
+      "type": "array",
+      "items": {
+        "type": "object"
+      }
+    },
+    "materialIds": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      }
+    },
+    "materials": {
+      "type": "array",
+      "items": {
+        "type": "object"
+      }
+    },
+    "textures": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      }
+    },
+    "samplers": {
+      "type": "array",
+      "items": {
+        "type": "object"
+      }
+    }
+  }
+}
diff --git a/schema/spot.schema.json b/schema/spot.schema.json
new file mode 100644
index 0000000..4a3cacc
--- /dev/null
+++ b/schema/spot.schema.json
@@ -0,0 +1,59 @@
+{
+  "$id": "https://raw.githubusercontent.com/empty-sekai/ournotes-player/main/schema/spot.schema.json",
+  "title": "spot document",
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "required": [
+    "spotId",
+    "master",
+    "name",
+    "tapTalk",
+    "situationSettings",
+    "controller",
+    "characters",
+    "spineCharacters",
+    "skeletons",
+    "matrixConvention"
+  ],
+  "properties": {
+    "spotId": {
+      "type": "integer"
+    },
+    "master": {
+      "type": "object"
+    },
+    "name": {
+      "type": "object"
+    },
+    "tapTalk": {
+      "type": "object"
+    },
+    "situationSettings": {
+      "type": "object"
+    },
+    "controller": {
+      "type": "object"
+    },
+    "characters": {
+      "type": "array",
+      "items": {
+        "type": "object"
+      }
+    },
+    "spineCharacters": {
+      "type": "array",
+      "items": {
+        "type": "object"
+      }
+    },
+    "skeletons": {
+      "type": "array",
+      "items": {
+        "type": "object"
+      }
+    },
+    "matrixConvention": {
+      "type": "string"
+    }
+  }
+}
diff --git a/schema/story-fonts.schema.json b/schema/story-fonts.schema.json
index 938a32e..965acd3 100644
--- a/schema/story-fonts.schema.json
+++ b/schema/story-fonts.schema.json
@@ -995,7 +995,10 @@
           }
         },
         "localized": {
-          "type": "object",
+          "type": [
+            "object",
+            "null"
+          ],
           "required": [
             "fontAsset",
             "material",
diff --git a/schema/story-simple-ui.schema.json b/schema/story-simple-ui.schema.json
index 7ac2542..7e693fb 100644
--- a/schema/story-simple-ui.schema.json
+++ b/schema/story-simple-ui.schema.json
@@ -121,7 +121,10 @@
         ],
         "properties": {
           "localized": {
-            "type": "object",
+            "type": [
+              "object",
+              "null"
+            ],
             "required": [
               "fontAsset",
               "material",
diff --git a/schema/story-sound.schema.json b/schema/story-sound.schema.json
new file mode 100644
index 0000000..54bbfc1
--- /dev/null
+++ b/schema/story-sound.schema.json
@@ -0,0 +1,56 @@
+{
+  "$id": "https://raw.githubusercontent.com/empty-sekai/ournotes-player/main/schema/story-sound.schema.json",
+  "title": "story-sound document",
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "additionalProperties": {
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "type": "object",
+    "required": [
+      "file",
+      "sampleRate",
+      "samples"
+    ],
+    "properties": {
+      "file": {
+        "type": "string"
+      },
+      "sampleRate": {
+        "type": "integer",
+        "minimum": 1
+      },
+      "samples": {
+        "type": "integer",
+        "minimum": 0
+      },
+      "channels": {
+        "type": "integer",
+        "minimum": 1
+      },
+      "categories": {
+        "type": "array",
+        "items": {
+          "type": "string"
+        }
+      },
+      "encoderDelay": {
+        "type": "integer",
+        "minimum": 0
+      },
+      "loopStart": {
+        "type": [
+          "integer",
+          "null"
+        ],
+        "minimum": 0
+      },
+      "loopEnd": {
+        "type": [
+          "integer",
+          "null"
+        ],
+        "minimum": 0
+      }
+    }
+  }
+}
diff --git a/schema/story-ui.schema.json b/schema/story-ui.schema.json
index 4414810..66d8933 100644
--- a/schema/story-ui.schema.json
+++ b/schema/story-ui.schema.json
@@ -196,7 +196,10 @@
         ],
         "properties": {
           "localized": {
-            "type": "object",
+            "type": [
+              "object",
+              "null"
+            ],
             "required": [
               "fontAsset",
               "material",
diff --git a/schema/story-video.schema.json b/schema/story-video.schema.json
new file mode 100644
index 0000000..effee2b
--- /dev/null
+++ b/schema/story-video.schema.json
@@ -0,0 +1,85 @@
+{
+  "$id": "https://raw.githubusercontent.com/empty-sekai/ournotes-player/main/schema/story-video.schema.json",
+  "title": "story-video document",
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "type": "object",
+  "required": [
+    "format",
+    "file",
+    "codec",
+    "width",
+    "height",
+    "displayWidth",
+    "displayHeight",
+    "frameRate",
+    "frames",
+    "tracks"
+  ],
+  "properties": {
+    "format": {
+      "const": 1
+    },
+    "file": {
+      "type": "string"
+    },
+    "codec": {
+      "type": "string"
+    },
+    "width": {
+      "type": "integer",
+      "minimum": 1
+    },
+    "height": {
+      "type": "integer",
+      "minimum": 1
+    },
+    "displayWidth": {
+      "type": "integer",
+      "minimum": 1
+    },
+    "displayHeight": {
+      "type": "integer",
+      "minimum": 1
+    },
+    "frameRate": {
+      "type": "array",
+      "minItems": 2,
+      "maxItems": 2,
+      "items": {
+        "type": "integer",
+        "minimum": 1
+      }
+    },
+    "frames": {
+      "type": "integer",
+      "minimum": 0
+    },
+    "tracks": {
+      "type": "array",
+      "items": {
+        "$schema": "https://json-schema.org/draft/2020-12/schema",
+        "type": "object",
+        "required": [
+          "kind",
+          "channel",
+          "codec"
+        ],
+        "properties": {
+          "kind": {
+            "type": "string"
+          },
+          "channel": {
+            "type": "integer",
+            "minimum": 0
+          },
+          "codec": {
+            "type": "string"
+          },
+          "source": {
+            "type": "string"
+          }
+        }
+      }
+    }
+  }
+}
diff --git a/scripts/validate-data.mjs b/scripts/validate-data.mjs
index c5d2264..1a26ab2 100644
--- a/scripts/validate-data.mjs
+++ b/scripts/validate-data.mjs
@@ -55,6 +55,8 @@ import { compile } from "./lib/json-schema.mjs";
 const here = path.dirname(fileURLToPath(import.meta.url));
 const schema = (name) => compile(JSON.parse(fs.readFileSync(path.join(here, "..", "schema", `${name}.schema.json`), "utf8")));
 const S = {
+  prefab: schema("prefab"),
+  room: schema("room"), spot: schema("spot"), video: schema("story-video"), sound: schema("story-sound"), crilips: schema("crilips"),
   charts: schema("charts"), manifest: schema("manifest"), live: schema("live"), score: schema("score"),
   scene: schema("live-scene"), notes: schema("live-notes"), noteskin: schema("live-noteskin"),
   noteeffect: schema("live-noteeffect"), sounds: schema("live-sounds"), music: schema("live-music"), models: schema("models"), product: schema("product"), modelJson: schema("model-json"),
@@ -662,6 +664,7 @@ function nodeList(pf, where, errs) {
     for (const k of ["localPosition", "localRotation", "localScale"]) if (!isObj(n[k])) { errs.push(`${where}: ${n.path} has no ${k}`); return; }
     paths.add(n.path);
   }
+  errs.push(...S.prefab(pf).map((error) => `${where}: ${error}`));
 }
 
 // ------------------------------------------------------------------------------------------------ one Live2D model
@@ -1275,6 +1278,7 @@ class Story extends Product {
       if (!sheet || !d.parts.sounds[sheet]) this.err("episode.json", `sound ${id}: cue sheet not in parts.sounds`);
       else if (!d.cues(sheet)[row._cueName]) this.err("episode.json", `sound ${id}: cue ${row._cueName} not in ${sheet}`);
     }
+    for (const sheet of Object.keys(d.parts.sounds)) for (const error of S.sound(d.cues(sheet))) this.err(`cues.json ${sheet}`, error);
     for (const [sheet, path] of Object.entries(d.parts.sounds)) for (const [name, cue] of Object.entries(d.cues(sheet))) {
       const where = `${productDir(path)}/cues.json ${name}`;
       if (!Number.isInteger(cue.sampleRate) || !Number.isInteger(cue.samples) || !(cue.sampleRate > 0) || cue.samples < 0) { this.err(where, "invalid sampleRate/samples"); continue; }
@@ -1287,6 +1291,7 @@ class Story extends Product {
     }
     if (d.parts.crilips) {
       const { descriptor: desc, data } = d.crilips, floats = data.byteLength / 4;
+      for (const error of S.crilips(desc)) this.err("crilips.json", error);
       if (desc.dtype !== "float32" || desc.order !== "LE") this.err("crilips.json", "expected float32 LE");
       if (floats !== desc.total_floats) this.err("crilips.bin", `length ${floats} differs from total_floats ${desc.total_floats}`);
       for (const block of desc.blocks || []) if (!Number.isInteger(block.offset) || !Number.isInteger(block.count) || block.offset < 0 || block.count < 0 || block.offset + block.count > floats)
@@ -1294,7 +1299,11 @@ class Story extends Product {
       if (!Array.isArray(desc.blocks) || !isObj(desc.constants) || !isObj(desc.frontend)) this.err("crilips.json", "blocks/constants/frontend missing");
     }
     for (const [id, row] of Object.entries(e.videos)) if (row._assetName?.trim()) {
-      try { const v = d.videoFor(id); if (!this.store.has(v.file)) this.err("video.json", `${v.file} missing`); } catch (error) { this.err("episode.json", error.message); }
+      try {
+        const v = d.videoFor(id);
+        for (const error of S.video(v)) this.err("video.json", error);
+        if (!this.store.has(v.file)) this.err("video.json", `${v.file} missing`);
+      } catch (error) { this.err("episode.json", error.message); }
     }
   }
 
@@ -1302,6 +1311,10 @@ class Story extends Product {
   materialKeywords() {
     const data = this.data, objects = this.objectsView, result = new Map();
     if (data.host?.kind !== "home") return result;
+    for (const name of ["room", "spot"]) {
+      const doc = data.document(data.host.home.parts[name], `${name}.json`);
+      for (const error of S[name](doc)) this.err(`${name}.json`, error);
+    }
     const scene = new HomeScene(data, objects), home = data.host.home, graphics = data.scene.graphics;
     const hostManifest = this.partCache.get(Object.values(data.parts.host)[0]);
     // The host retains the prefab dependency graph. Only room renderers and selected UI subtrees are drawn.
diff --git a/tests/unit/prefab-schema.test.mjs b/tests/unit/prefab-schema.test.mjs
new file mode 100644
index 0000000..8d9f2ec
--- /dev/null
+++ b/tests/unit/prefab-schema.test.mjs
@@ -0,0 +1,28 @@
+import assert from "node:assert/strict";
+import fs from "node:fs";
+import { test } from "node:test";
+import { compile } from "../../scripts/lib/json-schema.mjs";
+import { node, mb } from "./live2d-objects.mjs";
+
+const validate = compile(JSON.parse(fs.readFileSync(new URL("../../schema/prefab.schema.json", import.meta.url), "utf8")));
+const prefab = () => ({ name: "Root", nodes: [node("Root", [mb("Example", { enabled: true })])] });
+
+test("prefab schemas describe numeric transforms and typed component fields", () => {
+  const doc = prefab();
+  assert.deepEqual(validate(doc), []);
+  delete doc.nodes[0].localPosition.x;
+  assert.ok(validate(doc).some((e) => e.includes("x")));
+  doc.nodes[0].localPosition.x = "zero";
+  assert.ok(validate(doc).some((e) => e.includes("number")));
+});
+
+test("prefab schemas check component identity and RectTransform vectors", () => {
+  const doc = prefab();
+  doc.nodes[0].components[0].script = 3;
+  assert.ok(validate(doc).length);
+  doc.nodes[0].components[0].script = null;
+  doc.nodes[0].rect = { m_Pivot: { x: 0.5, y: 0.5 } };
+  assert.deepEqual(validate(doc), []);
+  doc.nodes[0].rect.m_Pivot.y = null;
+  assert.ok(validate(doc).length);
+});
diff --git a/tests/unit/story-schema.test.mjs b/tests/unit/story-schema.test.mjs
index a7ec443..791a69c 100644
--- a/tests/unit/story-schema.test.mjs
+++ b/tests/unit/story-schema.test.mjs
@@ -97,6 +97,7 @@ test("fonts bind TMP component ids to the selected font and material", () => {
   fails(fontEdit((d, f) => { d.texts[f.textId].font.fontAsset = "Absent"; }), /font asset Absent not in fonts/);
   fails(fontEdit((d, f) => { d.texts[f.textId].font.material = "Absent"; }), /material Absent not in materials/);
   passes(fontEdit((d, f) => { d.texts[f.textId].localized = { fontAsset: "Source", material: "Source", lineSpacing: 0 }; }));
+  passes(fontEdit((d, f) => { d.texts[f.textId].localized = null; }));
 });
 
 test("font glyphs fit their declared PNG pages", () => {