diff --git a/.cursor/plans/deterministic_asset_fingerprints_2026-07-13.plan.md b/.cursor/plans/deterministic_asset_fingerprints_2026-07-13.plan.md
new file mode 100644
index 0000000..13bf4d1
--- /dev/null
+++ b/.cursor/plans/deterministic_asset_fingerprints_2026-07-13.plan.md
@@ -0,0 +1,35 @@
+# Deterministic Imported-Asset Fingerprints
+
+## Scope
+
+Implement Gitea #56 so imported-source identity is content-addressed and editor/validator runs do
+not rewrite project artifacts because checkout timestamps or serialization whitespace changed.
+
+## Contract
+
+- Persist one shared fingerprint for imported model, texture, and audio sources: byte length plus a
+  BLAKE3 digest of the exact source bytes.
+- Do not persist or compare source mtimes as semantic identity. Legacy timestamp fields remain
+  readable but are ignored.
+- Static-mesh and animation manifests use the same content identity as the asset registry.
+- Preserve stable registry UUIDs across metadata-only drift and uniquely identifiable source moves.
+- Before writing a registry or generated manifest, compare the parsed semantic document; preserve
+  the existing bytes when the result is equivalent.
+- Project validators stay read-only and validate both length and digest, including same-size edits.
+
+## Implementation
+
+1. Add the shared fingerprint type and migrate animation/static-mesh contracts.
+2. Persist fingerprints for model, texture, and audio registry records and generalize move recovery.
+3. Make registry and manifest publication semantic and byte-preserving.
+4. Extend static-mesh and registry validation plus focused migration/read-only tests.
+5. Update ADRs, asset-pipeline docs, CI clean-worktree assertion, and committed generated artifacts.
+
+## Verification
+
+- Focused editor and scene tests for mtime-only drift, same-size changes, legacy manifests,
+  byte-preserving equivalent refresh, imported source kinds, and read-only validation.
+- Formatting, diff check, clippy, and workspace all-target tests.
+- Native editor startup and asset refresh with before/after Git status and source timestamp drift.
+- `cargo validate-levels --project .` and `cargo validate-samples --project .`, followed by a clean
+  worktree assertion. Packaged-runtime tests remain deferred by owner direction.
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 0c46e15..1ea051e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -63,6 +63,11 @@ jobs:
       - name: Validate editor sample pack
         run: cargo validate-samples
 
+      - name: Assert validation leaves checkout clean
+        run: |
+          git diff --exit-code
+          test -z "$(git ls-files --others --exclude-standard)"
+
       - name: Clippy launch feature matrix
         run: cargo clippy -p editor -p game --bins --features dev,hot-reload -- -D warnings
 
diff --git a/README.md b/README.md
index 840c5b1..e90b385 100644
--- a/README.md
+++ b/README.md
@@ -377,6 +377,7 @@ The `.vscode/` folder is preconfigured:
 - [ADR 0017: Normalized Static Mesh Assets](docs/adr/0017-normalized-static-mesh-assets.md)
 - [ADR 0034: Registry-driven Authoring Components](docs/adr/0034-registry-driven-authoring-components.md)
 - [ADR 0037: Collaborative Authored-File Safety](docs/adr/0037-collaborative-authored-file-safety.md)
+- [ADR 0043: Content-Addressed Import Fingerprints](docs/adr/0043-content-addressed-import-fingerprints.md)
 
 ## Project Layout
 
@@ -428,6 +429,9 @@ crates/
 - [x] Production operator invariants across palette dispatch, assets/material drops, brush/terrain/physics modal tools, grouping/lighting, and the transform finalizer: stable terminal status, exact cancel/failure rollback, helper cleanup, grouped history, and repeated undo/redo projections ([testing contract](docs/editor/operator-regression-testing.md), [evaluation](docs/editor/evaluations/operator-invariants/), [Gitea #33](https://git.spacetrainclubhouse.com/Falling-Metal-Interactive/Blacksite/issues/33))
 - [x] Verify: `cargo fmt --check` / `cargo check --workspace` / `cargo clippy --workspace` / strict foundation clippy / `cargo test -p sim`
 - [x] Stable asset registry with UUIDs + import settings in asset browser details
+- [x] Deterministic imported-source fingerprints for models, textures, and audio; BLAKE3-backed
+  static/animation manifests; byte-preserving equivalent refresh; and read-only validator checkout
+  assertions ([ADR 0043](docs/adr/0043-content-addressed-import-fingerprints.md), [Gitea #56](https://git.spacetrainclubhouse.com/Falling-Metal-Interactive/Blacksite/issues/56))
 - [x] Asset Browser expandable model subasset shelves, independent mesh/material/texture thumbnails, staged import/material details with shader-schema parameters, context actions, and trash-first file removal
 - [x] Audio clip catalog/import foundation for Ogg, WAV, MP3, and FLAC with dedicated filtering, file details, and stable runtime-resolvable asset references
 - [x] Audio source/listener authoring, non-dirty spatial audition, viewport icons/range gizmos, stable buses, PIE/runtime parity, device diagnostics, and shared release validation ([ADR 0030](docs/adr/0030-audio-authoring-and-bus-schema.md); production acceptance completed in [Gitea #47](https://git.spacetrainclubhouse.com/Falling-Metal-Interactive/Blacksite/issues/47))
diff --git a/assets/.index/registry.ron b/assets/.index/registry.ron
index 7b190f8..92e25b4 100644
--- a/assets/.index/registry.ron
+++ b/assets/.index/registry.ron
@@ -4,6 +4,10 @@
         path: "assets/audio/editor_audition_tone.ogg",
         label: "editor_audition_tone",
         kind_tag: "AudioClip",
+        source_fingerprint: Some((
+            byte_len: 4450,
+            content_hash: "8ef56184ab5b5cd135e45df152f8a95737023420947f3d08c9b3e3605e55a349",
+        )),
         import_settings: (
             scale: 1.0,
             generate_collider: true,
@@ -22,6 +26,10 @@
         path: "assets/audio/Puzzle Lobby.mp3",
         label: "Puzzle Lobby",
         kind_tag: "AudioClip",
+        source_fingerprint: Some((
+            byte_len: 1680820,
+            content_hash: "3b5a401dbaccfdbda540c60070ce259fb506d7da548f45008eb2b3fa720b4b57",
+        )),
         import_settings: (
             scale: 1.0,
             generate_collider: true,
@@ -76,6 +84,10 @@
         path: "assets/models/painted_wooden_chair_02_2k.fbx",
         label: "painted_wooden_chair_02_2k",
         kind_tag: "Model",
+        source_fingerprint: Some((
+            byte_len: 59964,
+            content_hash: "b12973a62dcb44589e380ea833eade726ae98a86c81084c842ee3801866d6a46",
+        )),
         import_settings: (
             scale: 1.0,
             generate_collider: true,
@@ -94,6 +106,10 @@
         path: "assets/models/RobotExpressive.glb",
         label: "RobotExpressive",
         kind_tag: "Model",
+        source_fingerprint: Some((
+            byte_len: 463988,
+            content_hash: "5869cb813e6a6093eda7af2824a9c13a582750e0443e88ce7c991a1f83415521",
+        )),
         import_settings: (
             scale: 1.0,
             generate_collider: true,
@@ -112,6 +128,10 @@
         path: "assets/models/robot_expressive.glb",
         label: "robot_expressive",
         kind_tag: "Model",
+        source_fingerprint: Some((
+            byte_len: 463988,
+            content_hash: "5869cb813e6a6093eda7af2824a9c13a582750e0443e88ce7c991a1f83415521",
+        )),
         import_settings: (
             scale: 1.0,
             generate_collider: true,
@@ -130,6 +150,10 @@
         path: "assets/textures/metal_stool_01_nor_gl_2k.jpg",
         label: "metal_stool_01_nor_gl_2k",
         kind_tag: "Texture",
+        source_fingerprint: Some((
+            byte_len: 2779150,
+            content_hash: "8c0aa4cf4270c9bf7217fba40b2b48878972ee59cff851cb8dfa57a90f4f373b",
+        )),
         import_settings: (
             scale: 1.0,
             generate_collider: true,
@@ -148,6 +172,10 @@
         path: "assets/textures/metal_stool_01_arm_2k.jpg",
         label: "metal_stool_01_arm_2k",
         kind_tag: "Texture",
+        source_fingerprint: Some((
+            byte_len: 3152060,
+            content_hash: "31b2249ed7b50d3a021312a1e299167897513710ee8ded75c5c5e56aad592e10",
+        )),
         import_settings: (
             scale: 1.0,
             generate_collider: true,
@@ -166,6 +194,10 @@
         path: "assets/textures/metal_stool_01_diff_2k.jpg",
         label: "metal_stool_01_diff_2k",
         kind_tag: "Texture",
+        source_fingerprint: Some((
+            byte_len: 2603921,
+            content_hash: "e0b9dee5b09f1968e7c6ea82eb9a157d303c25d0600913b8b9c809adf50b73c8",
+        )),
         import_settings: (
             scale: 1.0,
             generate_collider: true,
diff --git a/assets/meshes/generated/113f74df-e39c-41d4-9b5b-e48efe541f7f.static_mesh.ron b/assets/meshes/generated/113f74df-e39c-41d4-9b5b-e48efe541f7f.static_mesh.ron
index 303ecca..a836a4e 100644
--- a/assets/meshes/generated/113f74df-e39c-41d4-9b5b-e48efe541f7f.static_mesh.ron
+++ b/assets/meshes/generated/113f74df-e39c-41d4-9b5b-e48efe541f7f.static_mesh.ron
@@ -1,5 +1,5 @@
 (
-    schema_version: 3,
+    schema_version: 4,
     asset_id: "113f74df-e39c-41d4-9b5b-e48efe541f7f",
     label: "RobotExpressive",
     source: (
@@ -7,7 +7,7 @@
         format: "glb",
         fingerprint: (
             byte_len: 463988,
-            modified_unix_secs: 1783799272,
+            content_hash: "5869cb813e6a6093eda7af2824a9c13a582750e0443e88ce7c991a1f83415521",
         ),
         dependencies: [],
     ),
diff --git a/assets/meshes/generated/3f63f359-45eb-4cb2-8970-71921cbd7bd0.static_mesh.ron b/assets/meshes/generated/3f63f359-45eb-4cb2-8970-71921cbd7bd0.static_mesh.ron
index bbf92f0..4363ddd 100644
--- a/assets/meshes/generated/3f63f359-45eb-4cb2-8970-71921cbd7bd0.static_mesh.ron
+++ b/assets/meshes/generated/3f63f359-45eb-4cb2-8970-71921cbd7bd0.static_mesh.ron
@@ -1,5 +1,5 @@
 (
-    schema_version: 3,
+    schema_version: 4,
     asset_id: "3f63f359-45eb-4cb2-8970-71921cbd7bd0",
     label: "robot_expressive",
     source: (
@@ -7,7 +7,7 @@
         format: "glb",
         fingerprint: (
             byte_len: 463988,
-            modified_unix_secs: 1783750957,
+            content_hash: "5869cb813e6a6093eda7af2824a9c13a582750e0443e88ce7c991a1f83415521",
         ),
         dependencies: [],
     ),
diff --git a/assets/meshes/generated/b98ef565-3500-49e7-9935-f685fa9b2594.static_mesh.ron b/assets/meshes/generated/b98ef565-3500-49e7-9935-f685fa9b2594.static_mesh.ron
index 683980a..530c1ee 100644
--- a/assets/meshes/generated/b98ef565-3500-49e7-9935-f685fa9b2594.static_mesh.ron
+++ b/assets/meshes/generated/b98ef565-3500-49e7-9935-f685fa9b2594.static_mesh.ron
@@ -1,5 +1,5 @@
 (
-    schema_version: 3,
+    schema_version: 4,
     asset_id: "b98ef565-3500-49e7-9935-f685fa9b2594",
     label: "painted_wooden_chair_02_2k",
     source: (
@@ -7,7 +7,7 @@
         format: "fbx",
         fingerprint: (
             byte_len: 59964,
-            modified_unix_secs: 1780713434,
+            content_hash: "b12973a62dcb44589e380ea833eade726ae98a86c81084c842ee3801866d6a46",
         ),
         dependencies: [],
     ),
diff --git a/crates/editor/src/assets/animation.rs b/crates/editor/src/assets/animation.rs
index d1b236d..acf10a7 100644
--- a/crates/editor/src/assets/animation.rs
+++ b/crates/editor/src/assets/animation.rs
@@ -3,7 +3,6 @@
 use std::collections::BTreeSet;
 use std::fs;
 use std::path::Path;
-use std::time::UNIX_EPOCH;
 
 use serde::Deserialize;
 use shared::{
@@ -14,6 +13,7 @@ use shared::{
 };
 
 use crate::asset_db::AssetRecord;
+use crate::assets::fingerprint::write_pretty_ron_if_changed;
 
 pub fn animation_manifest_path(asset_id: &str) -> String {
     format!("{ANIMATION_ARTIFACT_DIR}/{asset_id}.animation.ron")
@@ -32,15 +32,9 @@ pub fn refresh_animation_artifact(record: &mut AssetRecord) -> Result<AnimationM
     record.dependencies.sort();
     record.dependencies.dedup();
 
-    let text = ron::ser::to_string_pretty(&manifest, ron::ser::PrettyConfig::default())
-        .map_err(|error| format!("could not serialize animation manifest: {error}"))?;
-    if let Some(parent) = Path::new(&path).parent() {
-        fs::create_dir_all(parent)
-            .map_err(|error| format!("could not create {}: {error}", parent.display()))?;
-    }
-    if fs::read_to_string(&path).ok().as_deref() != Some(text.as_str()) {
-        fs::write(&path, text)
-            .map_err(|error| format!("could not write animation manifest {path}: {error}"))?;
+    if write_pretty_ron_if_changed(&path, &manifest)
+        .map_err(|error| format!("could not publish animation manifest {path}: {error}"))?
+    {
         bevy::log::info!(
             "Animation manifest refreshed: source={} artifact={} skeletons={} clips={} runtime_supported={}",
             record.path,
@@ -63,7 +57,7 @@ pub fn load_animation_manifest(path: &str) -> Result<AnimationManifest, String>
 pub fn build_animation_manifest(record: &AssetRecord) -> Result<AnimationManifest, String> {
     let bytes = fs::read(&record.path)
         .map_err(|error| format!("could not read {}: {error}", record.path))?;
-    let fingerprint = source_fingerprint(&record.path, &bytes)?;
+    let fingerprint = source_fingerprint(&bytes);
     let format = source_format(&record.path)?;
     match format.as_str() {
         "gltf" | "glb" => build_gltf_manifest(record, format, fingerprint, &bytes),
@@ -582,19 +576,8 @@ fn fbx_matrix_bytes(matrix: &ufbx::Matrix) -> Vec<u8> {
     .collect()
 }
 
-fn source_fingerprint(path: &str, bytes: &[u8]) -> Result<AnimationSourceFingerprint, String> {
-    let metadata = fs::metadata(path).map_err(|error| format!("could not stat {path}: {error}"))?;
-    let modified_unix_secs = metadata
-        .modified()
-        .ok()
-        .and_then(|time| time.duration_since(UNIX_EPOCH).ok())
-        .map(|duration| duration.as_secs())
-        .unwrap_or_default();
-    Ok(AnimationSourceFingerprint {
-        byte_len: metadata.len(),
-        modified_unix_secs,
-        content_hash: blake3::hash(bytes).to_hex().to_string(),
-    })
+fn source_fingerprint(bytes: &[u8]) -> AnimationSourceFingerprint {
+    AnimationSourceFingerprint::from_bytes(bytes)
 }
 
 fn source_format(path: &str) -> Result<String, String> {
@@ -626,6 +609,7 @@ mod tests {
             path: path.to_string_lossy().replace('\\', "/"),
             label: "Animated Hero".into(),
             kind_tag: "Model".into(),
+            source_fingerprint: None,
             import_settings: ImportSettings::default(),
             dependencies: Vec::new(),
         }
@@ -754,6 +738,30 @@ mod tests {
         fs::remove_dir_all(root).unwrap();
     }
 
+    #[test]
+    fn legacy_mtime_metadata_does_not_rewrite_equivalent_animation_manifest() {
+        let root =
+            std::env::temp_dir().join(format!("blacksite-animation-legacy-{}", Uuid::new_v4()));
+        let path = write_animated_gltf(&root);
+        let manifest = build_animation_manifest(&fixture_record(&path)).unwrap();
+        let canonical =
+            ron::ser::to_string_pretty(&manifest, ron::ser::PrettyConfig::default()).unwrap();
+        let marker = format!("byte_len: {},", manifest.source.fingerprint.byte_len);
+        let legacy = canonical.replacen(
+            &marker,
+            &format!("{marker}\n            modified_unix_secs: 123456,"),
+            1,
+        );
+        assert_ne!(legacy, canonical);
+        let artifact = root.join("legacy.animation.ron");
+        fs::write(&artifact, &legacy).unwrap();
+
+        assert!(!write_pretty_ron_if_changed(&artifact, &manifest).unwrap());
+        assert_eq!(fs::read_to_string(&artifact).unwrap(), legacy);
+
+        fs::remove_dir_all(root).unwrap();
+    }
+
     #[test]
     fn explicit_default_clip_is_stable_and_stale_ids_are_diagnostic() {
         let root =
diff --git a/crates/editor/src/assets/asset_db.rs b/crates/editor/src/assets/asset_db.rs
index 63d1afb..d5cea6e 100644
--- a/crates/editor/src/assets/asset_db.rs
+++ b/crates/editor/src/assets/asset_db.rs
@@ -2,9 +2,12 @@
 
 use bevy::prelude::*;
 use serde::{Deserialize, Serialize};
+use shared::AssetSourceFingerprint;
 use std::collections::{HashMap, HashSet};
 use uuid::Uuid;
 
+use crate::assets::fingerprint::{fingerprint_file, write_pretty_ron_if_changed};
+
 /// Stable asset identity for dependency tracking and prefab references.
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq, Hash)]
 pub struct AssetId(pub Uuid);
@@ -93,6 +96,8 @@ pub struct AssetRecord {
     pub path: String,
     pub label: String,
     pub kind_tag: String,
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub source_fingerprint: Option<AssetSourceFingerprint>,
     #[serde(default)]
     pub import_settings: ImportSettings,
     #[serde(default)]
@@ -122,9 +127,10 @@ fn sync_registry_from_browser(
         return;
     }
 
-    let mut existing: HashMap<String, AssetRecord> = registry
-        .records
-        .drain(..)
+    let previous_records = std::mem::take(&mut registry.records);
+    let mut existing: HashMap<String, AssetRecord> = previous_records
+        .iter()
+        .cloned()
         .map(|record| (record.path.clone(), record))
         .collect();
     let current_paths = assets
@@ -146,12 +152,30 @@ fn sync_registry_from_browser(
         seen_paths.insert(path.clone(), ());
 
         let kind_tag = format!("{:?}", asset.kind);
+        let source_fingerprint = if imported_source_kind(&kind_tag) {
+            match fingerprint_file(&path) {
+                Ok(fingerprint) => Some(fingerprint),
+                Err(error) => {
+                    warn!("Imported source fingerprint failed for {path}: {error}");
+                    None
+                }
+            }
+        } else {
+            None
+        };
         let mut record = if let Some(mut prior) = existing.remove(&path).or_else(|| {
-            take_uniquely_moved_model_record(&mut existing, &current_paths, &path, &kind_tag)
+            source_fingerprint.as_ref().and_then(|fingerprint| {
+                take_uniquely_moved_import_record(
+                    &mut existing,
+                    &current_paths,
+                    &kind_tag,
+                    fingerprint,
+                )
+            })
         }) {
             if prior.path != path {
                 info!(
-                    "Asset registry preserved model identity {} across move {} -> {}",
+                    "Asset registry preserved imported source identity {} across move {} -> {}",
                     prior.id.as_string(),
                     prior.path,
                     path
@@ -159,18 +183,26 @@ fn sync_registry_from_browser(
                 prior.path = path.clone();
             }
             prior.label = asset.label.clone();
-            prior.kind_tag = kind_tag;
+            prior.kind_tag = kind_tag.clone();
             prior
         } else {
             AssetRecord {
                 id: AssetId::new(),
                 path: path.clone(),
                 label: asset.label.clone(),
-                kind_tag,
+                kind_tag: kind_tag.clone(),
+                source_fingerprint: None,
                 import_settings: ImportSettings::default(),
                 dependencies: Vec::new(),
             }
         };
+        if imported_source_kind(&kind_tag) {
+            if let Some(source_fingerprint) = source_fingerprint {
+                record.source_fingerprint = Some(source_fingerprint);
+            }
+        } else {
+            record.source_fingerprint = None;
+        }
         if record.kind_tag == "Model" {
             if let Err(error) = super::refresh_model_artifacts(&mut record) {
                 warn!(
@@ -183,7 +215,7 @@ fn sync_registry_from_browser(
         next_records.push(record);
     }
 
-    let changed = registry.records != next_records;
+    let changed = previous_records != next_records;
     registry.records = next_records;
     if changed {
         registry.index_dirty = true;
@@ -198,26 +230,28 @@ fn sync_registry_from_browser(
     }
 }
 
-fn take_uniquely_moved_model_record(
+fn imported_source_kind(kind_tag: &str) -> bool {
+    matches!(kind_tag, "Model" | "Texture" | "AudioClip")
+}
+
+fn take_uniquely_moved_import_record(
     existing: &mut HashMap<String, AssetRecord>,
     current_paths: &HashSet<String>,
-    new_path: &str,
     kind_tag: &str,
+    fingerprint: &AssetSourceFingerprint,
 ) -> Option<AssetRecord> {
-    if kind_tag != "Model" {
+    if !imported_source_kind(kind_tag) {
         return None;
     }
-    let bytes = std::fs::read(new_path).ok()?;
-    let content_hash = blake3::hash(&bytes).to_hex().to_string();
     let candidates = existing
         .iter()
         .filter_map(|(old_path, record)| {
-            if current_paths.contains(old_path) || record.kind_tag != "Model" {
+            if current_paths.contains(old_path) || record.kind_tag != kind_tag {
                 return None;
             }
-            let manifest_path = record.import_settings.animation_manifest_path.as_deref()?;
-            let manifest = super::animation::load_animation_manifest(manifest_path).ok()?;
-            (manifest.source.fingerprint.content_hash == content_hash).then(|| old_path.clone())
+            recorded_source_fingerprint(record)
+                .is_some_and(|prior| prior == *fingerprint)
+                .then(|| old_path.clone())
         })
         .collect::<Vec<_>>();
     if candidates.len() != 1 {
@@ -226,6 +260,15 @@ fn take_uniquely_moved_model_record(
     existing.remove(&candidates[0])
 }
 
+fn recorded_source_fingerprint(record: &AssetRecord) -> Option<AssetSourceFingerprint> {
+    record.source_fingerprint.clone().or_else(|| {
+        let manifest_path = record.import_settings.animation_manifest_path.as_deref()?;
+        super::animation::load_animation_manifest(manifest_path)
+            .ok()
+            .map(|manifest| manifest.source.fingerprint)
+    })
+}
+
 pub fn find_asset_by_path(registry: &AssetRegistry, path: &str) -> Option<AssetRecord> {
     registry
         .records
@@ -262,11 +305,16 @@ pub fn ensure_asset_record(
     if let Some(record) = find_asset_by_path(registry, &path) {
         return Ok(record);
     }
+    let kind_tag = kind_tag.into();
+    let source_fingerprint = imported_source_kind(&kind_tag)
+        .then(|| fingerprint_file(&path).ok())
+        .flatten();
     let record = AssetRecord {
         id: AssetId::new(),
         path,
         label: label.into(),
-        kind_tag: kind_tag.into(),
+        kind_tag,
+        source_fingerprint,
         import_settings: ImportSettings::default(),
         dependencies: Vec::new(),
     };
@@ -292,6 +340,9 @@ pub fn update_import_settings(
     else {
         return false;
     };
+    if record.import_settings == settings {
+        return false;
+    }
     record.import_settings = settings;
     registry.index_dirty = true;
     true
@@ -302,13 +353,7 @@ pub fn registry_index_path() -> &'static str {
 }
 
 pub fn save_registry(registry: &AssetRegistry) -> Result<(), String> {
-    let path = registry_index_path();
-    if let Some(parent) = std::path::Path::new(path).parent() {
-        std::fs::create_dir_all(parent).map_err(|e| e.to_string())?;
-    }
-    let text = ron::ser::to_string_pretty(&registry.records, ron::ser::PrettyConfig::default())
-        .map_err(|e| e.to_string())?;
-    std::fs::write(path, text).map_err(|e| e.to_string())
+    write_pretty_ron_if_changed(registry_index_path(), &registry.records).map(|_| ())
 }
 
 pub fn load_registry() -> AssetRegistry {
@@ -333,6 +378,63 @@ mod tests {
         ANIMATION_MANIFEST_SCHEMA_VERSION,
     };
 
+    #[test]
+    fn imported_source_policy_covers_model_texture_and_audio_only() {
+        for kind in ["Model", "Texture", "AudioClip"] {
+            assert!(imported_source_kind(kind), "missing imported kind {kind}");
+        }
+        for kind in ["Material", "Level", "Prefab", "PostProcessEffect"] {
+            assert!(
+                !imported_source_kind(kind),
+                "authored kind {kind} was hashed"
+            );
+        }
+    }
+
+    #[test]
+    fn legacy_registry_record_loads_without_forcing_a_new_identity() {
+        let source = r#"(
+            id: ("00000000-0000-0000-0000-000000000000"),
+            path: "assets/textures/legacy.png",
+            label: "Legacy",
+            kind_tag: "Texture",
+        )"#;
+        let record: AssetRecord = ron::from_str(source).unwrap();
+
+        assert_eq!(record.id, AssetId(Uuid::nil()));
+        assert!(record.source_fingerprint.is_none());
+        assert_eq!(record.import_settings, ImportSettings::default());
+    }
+
+    #[test]
+    fn content_match_preserves_every_imported_source_kind_across_move() {
+        let fingerprint = AssetSourceFingerprint::from_bytes(b"stable imported bytes");
+        for kind in ["Model", "Texture", "AudioClip"] {
+            let record = AssetRecord {
+                id: AssetId::new(),
+                path: format!("assets/old/{kind}"),
+                label: kind.into(),
+                kind_tag: kind.into(),
+                source_fingerprint: Some(fingerprint.clone()),
+                import_settings: ImportSettings::default(),
+                dependencies: Vec::new(),
+            };
+            let expected_id = record.id.clone();
+            let mut existing = HashMap::from([(record.path.clone(), record)]);
+
+            let moved = take_uniquely_moved_import_record(
+                &mut existing,
+                &HashSet::new(),
+                kind,
+                &fingerprint,
+            )
+            .expect("unique content identity should preserve the record");
+
+            assert_eq!(moved.id, expected_id);
+            assert!(existing.is_empty());
+        }
+    }
+
     fn moved_model_fixture(bytes: &[u8]) -> (std::path::PathBuf, std::path::PathBuf, AssetRecord) {
         let key = Uuid::new_v4();
         let source_path = std::env::temp_dir().join(format!("blacksite-moved-model-{key}.glb"));
@@ -351,7 +453,6 @@ mod tests {
                 format: "glb".into(),
                 fingerprint: AnimationSourceFingerprint {
                     byte_len: bytes.len() as u64,
-                    modified_unix_secs: 0,
                     content_hash: blake3::hash(bytes).to_hex().to_string(),
                 },
                 dependencies: Vec::new(),
@@ -371,6 +472,7 @@ mod tests {
             path: old_path,
             label: "Moved Model".into(),
             kind_tag: "Model".into(),
+            source_fingerprint: None,
             import_settings: ImportSettings {
                 animation_manifest_path: Some(manifest_path.to_string_lossy().into_owned()),
                 ..Default::default()
@@ -385,12 +487,13 @@ mod tests {
         let (source_path, manifest_path, record) = moved_model_fixture(b"stable model bytes");
         let expected_id = record.id.clone();
         let mut existing = HashMap::from([(record.path.clone(), record)]);
+        let fingerprint = fingerprint_file(&source_path).unwrap();
 
-        let moved = take_uniquely_moved_model_record(
+        let moved = take_uniquely_moved_import_record(
             &mut existing,
             &HashSet::new(),
-            &source_path.to_string_lossy(),
             "Model",
+            &fingerprint,
         )
         .expect("unique moved model should retain its registry record");
 
@@ -406,13 +509,10 @@ mod tests {
         let old_path = record.path.clone();
         let mut existing = HashMap::from([(old_path.clone(), record)]);
         let current_paths = HashSet::from([old_path]);
+        let fingerprint = fingerprint_file(&source_path).unwrap();
 
-        let moved = take_uniquely_moved_model_record(
-            &mut existing,
-            &current_paths,
-            &source_path.to_string_lossy(),
-            "Model",
-        );
+        let moved =
+            take_uniquely_moved_import_record(&mut existing, &current_paths, "Model", &fingerprint);
 
         assert!(moved.is_none());
         assert_eq!(existing.len(), 1);
diff --git a/crates/editor/src/assets/catalog.rs b/crates/editor/src/assets/catalog.rs
index baf8803..05205a2 100644
--- a/crates/editor/src/assets/catalog.rs
+++ b/crates/editor/src/assets/catalog.rs
@@ -1548,6 +1548,7 @@ mod tests {
                 path: asset.path.clone().unwrap(),
                 label: asset.label.clone(),
                 kind_tag: "AudioClip".into(),
+                source_fingerprint: None,
                 import_settings: Default::default(),
                 dependencies: Vec::new(),
             }],
@@ -1630,7 +1631,6 @@ mod tests {
                 format: "glb".into(),
                 fingerprint: shared::AnimationSourceFingerprint {
                     byte_len: 1,
-                    modified_unix_secs: 0,
                     content_hash: "fixture".into(),
                 },
                 dependencies: Vec::new(),
@@ -1663,6 +1663,7 @@ mod tests {
             path: "assets/models/robot.glb".into(),
             label: "Robot".into(),
             kind_tag: "Model".into(),
+            source_fingerprint: None,
             import_settings: crate::asset_db::ImportSettings {
                 animation_manifest_path: Some(manifest_path.to_string_lossy().into_owned()),
                 default_animation_clip_id: Some(clip_id.clone()),
diff --git a/crates/editor/src/assets/fingerprint.rs b/crates/editor/src/assets/fingerprint.rs
new file mode 100644
index 0000000..e2a0330
--- /dev/null
+++ b/crates/editor/src/assets/fingerprint.rs
@@ -0,0 +1,114 @@
+use std::fs;
+use std::path::Path;
+
+use serde::de::DeserializeOwned;
+use serde::Serialize;
+use shared::AssetSourceFingerprint;
+
+pub(crate) fn fingerprint_file(path: impl AsRef<Path>) -> Result<AssetSourceFingerprint, String> {
+    let path = path.as_ref();
+    let bytes = fs::read(path)
+        .map_err(|error| format!("could not read imported source {}: {error}", path.display()))?;
+    Ok(AssetSourceFingerprint::from_bytes(&bytes))
+}
+
+/// Writes canonical pretty RON only when the parsed document changes semantically.
+///
+/// Equivalent existing bytes, including custom formatting and final-newline policy, stay intact.
+pub(crate) fn write_pretty_ron_if_changed<T>(
+    path: impl AsRef<Path>,
+    value: &T,
+) -> Result<bool, String>
+where
+    T: DeserializeOwned + PartialEq + Serialize,
+{
+    let path = path.as_ref();
+    if fs::read_to_string(path)
+        .ok()
+        .and_then(|text| ron::from_str::<T>(&text).ok())
+        .is_some_and(|existing| existing == *value)
+    {
+        return Ok(false);
+    }
+
+    let text = ron::ser::to_string_pretty(value, ron::ser::PrettyConfig::default())
+        .map_err(|error| format!("could not serialize RON: {error}"))?;
+    if fs::read(path).ok().as_deref() == Some(text.as_bytes()) {
+        return Ok(false);
+    }
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent)
+            .map_err(|error| format!("could not create {}: {error}", parent.display()))?;
+    }
+    fs::write(path, text)
+        .map_err(|error| format!("could not write {}: {error}", path.display()))?;
+    Ok(true)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use serde::Deserialize;
+    use std::fs::{File, FileTimes};
+    use std::time::{Duration, SystemTime};
+    use uuid::Uuid;
+
+    #[derive(Debug, Deserialize, PartialEq, Serialize)]
+    struct Fixture {
+        count: u32,
+        label: String,
+    }
+
+    fn fixture_path(name: &str) -> std::path::PathBuf {
+        std::env::temp_dir().join(format!(
+            "blacksite-fingerprint-{name}-{}.ron",
+            Uuid::new_v4()
+        ))
+    }
+
+    #[test]
+    fn metadata_only_drift_does_not_change_content_identity() {
+        let path = fixture_path("mtime");
+        fs::write(&path, b"stable source bytes").unwrap();
+        let before = fingerprint_file(&path).unwrap();
+        File::options()
+            .write(true)
+            .open(&path)
+            .unwrap()
+            .set_times(
+                FileTimes::new().set_modified(SystemTime::now() + Duration::from_secs(86_400)),
+            )
+            .unwrap();
+
+        assert_eq!(fingerprint_file(&path).unwrap(), before);
+        fs::remove_file(path).unwrap();
+    }
+
+    #[test]
+    fn same_size_byte_change_updates_content_identity() {
+        let path = fixture_path("same-size");
+        fs::write(&path, b"source-a").unwrap();
+        let before = fingerprint_file(&path).unwrap();
+        fs::write(&path, b"source-b").unwrap();
+        let after = fingerprint_file(&path).unwrap();
+
+        assert_eq!(before.byte_len, after.byte_len);
+        assert_ne!(before.content_hash, after.content_hash);
+        fs::remove_file(path).unwrap();
+    }
+
+    #[test]
+    fn equivalent_ron_preserves_exact_existing_bytes() {
+        let path = fixture_path("semantic");
+        let existing = b"( label: \"stable\", count: 7, )\n\n";
+        fs::write(&path, existing).unwrap();
+        let value = Fixture {
+            count: 7,
+            label: "stable".into(),
+        };
+
+        assert!(!write_pretty_ron_if_changed(&path, &value).unwrap());
+        assert_eq!(fs::read(&path).unwrap(), existing);
+        fs::remove_file(path).unwrap();
+    }
+}
diff --git a/crates/editor/src/assets/mod.rs b/crates/editor/src/assets/mod.rs
index 57da715..48ca69d 100644
--- a/crates/editor/src/assets/mod.rs
+++ b/crates/editor/src/assets/mod.rs
@@ -3,6 +3,7 @@
 pub mod animation;
 pub mod asset_db;
 mod catalog;
+mod fingerprint;
 mod import;
 pub mod materials;
 pub mod operators;
diff --git a/crates/editor/src/assets/operators.rs b/crates/editor/src/assets/operators.rs
index acce012..1f4129d 100644
--- a/crates/editor/src/assets/operators.rs
+++ b/crates/editor/src/assets/operators.rs
@@ -228,7 +228,6 @@ mod tests {
                 format: "glb".into(),
                 fingerprint: AnimationSourceFingerprint {
                     byte_len: 1,
-                    modified_unix_secs: 0,
                     content_hash: "fixture".into(),
                 },
                 dependencies: Vec::new(),
@@ -265,6 +264,7 @@ mod tests {
             path: model_path.clone(),
             label: "Operator Fixture".into(),
             kind_tag: "Model".into(),
+            source_fingerprint: None,
             import_settings: ImportSettings {
                 animation_manifest_path: Some(path.to_string_lossy().into_owned()),
                 ..Default::default()
@@ -352,6 +352,7 @@ mod tests {
                 path: path.clone(),
                 label: "Impact".into(),
                 kind_tag: "AudioClip".into(),
+                source_fingerprint: None,
                 import_settings: Default::default(),
                 dependencies: Vec::new(),
             }],
@@ -502,6 +503,7 @@ mod tests {
                 path: material_path.clone(),
                 label: "Concrete".into(),
                 kind_tag: "Material".into(),
+                source_fingerprint: None,
                 import_settings: Default::default(),
                 dependencies: Vec::new(),
             }],
diff --git a/crates/editor/src/assets/static_mesh.rs b/crates/editor/src/assets/static_mesh.rs
index 61aed72..c64a6b7 100644
--- a/crates/editor/src/assets/static_mesh.rs
+++ b/crates/editor/src/assets/static_mesh.rs
@@ -2,7 +2,6 @@
 
 use std::fs;
 use std::path::Path;
-use std::time::UNIX_EPOCH;
 
 use bevy::gltf::GltfAssetLabel;
 use bevy::prelude::*;
@@ -15,11 +14,13 @@ use crate::asset_db::{
     AssetRecord, ImportSettings, MaterialImportPolicy, ModelHierarchyMode, ModelPlacementMode,
 };
 use shared::{
-    ComponentInstanceId, EditorAssetRef, MaterialRef, RendererMaterialSet, RendererMaterialSlot,
-    StaticMeshRenderer, StaticMeshRendererEntry,
+    AssetSourceFingerprint, ComponentInstanceId, EditorAssetRef, MaterialRef, RendererMaterialSet,
+    RendererMaterialSlot, StaticMeshRenderer, StaticMeshRendererEntry,
 };
 
-pub const STATIC_MESH_MANIFEST_SCHEMA: u32 = 3;
+use crate::assets::fingerprint::{fingerprint_file, write_pretty_ron_if_changed};
+
+pub const STATIC_MESH_MANIFEST_SCHEMA: u32 = 4;
 pub const STATIC_MESH_ARTIFACT_DIR: &str = "assets/meshes/generated";
 
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
@@ -42,11 +43,7 @@ pub struct StaticMeshSource {
     pub dependencies: Vec<String>,
 }
 
-#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
-pub struct StaticMeshSourceFingerprint {
-    pub byte_len: u64,
-    pub modified_unix_secs: u64,
-}
+pub type StaticMeshSourceFingerprint = AssetSourceFingerprint;
 
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
 pub struct StaticMeshImportSnapshot {
@@ -134,16 +131,9 @@ pub fn refresh_static_mesh_artifact(
     manifest.source.dependencies.dedup();
     record.dependencies = manifest.source.dependencies.clone();
 
-    let text = ron::ser::to_string_pretty(&manifest, ron::ser::PrettyConfig::default())
-        .map_err(|err| format!("could not serialize static mesh manifest: {err}"))?;
-    if let Some(parent) = Path::new(&path).parent() {
-        fs::create_dir_all(parent)
-            .map_err(|err| format!("could not create {}: {err}", parent.display()))?;
-    }
-    let should_write = fs::read_to_string(&path).ok().as_deref() != Some(text.as_str());
-    if should_write {
-        fs::write(&path, text)
-            .map_err(|err| format!("could not write static mesh manifest {path}: {err}"))?;
+    if write_pretty_ron_if_changed(&path, &manifest)
+        .map_err(|error| format!("could not publish static mesh manifest {path}: {error}"))?
+    {
         info!(
             "Static mesh manifest refreshed: source={} artifact={} parts={}",
             record.path,
@@ -287,7 +277,7 @@ fn part_effective_material_id(part: &StaticMeshPart) -> Option<String> {
 
 fn build_static_mesh_manifest(record: &AssetRecord) -> Result<StaticMeshManifest, String> {
     let format = source_format(&record.path)?;
-    let fingerprint = source_fingerprint(&record.path)?;
+    let fingerprint = fingerprint_file(&record.path)?;
     let import = StaticMeshImportSnapshot {
         scale: record.import_settings.scale,
         generate_collider: record.import_settings.generate_collider,
@@ -631,20 +621,6 @@ fn source_format(path: &str) -> Result<String, String> {
         .ok_or_else(|| format!("asset path `{path}` has no extension"))
 }
 
-fn source_fingerprint(path: &str) -> Result<StaticMeshSourceFingerprint, String> {
-    let metadata = fs::metadata(path).map_err(|err| format!("could not stat {path}: {err}"))?;
-    let modified_unix_secs = metadata
-        .modified()
-        .ok()
-        .and_then(|time| time.duration_since(UNIX_EPOCH).ok())
-        .map(|duration| duration.as_secs())
-        .unwrap_or_default();
-    Ok(StaticMeshSourceFingerprint {
-        byte_len: metadata.len(),
-        modified_unix_secs,
-    })
-}
-
 fn resolve_dependency(source_path: &str, uri: &str) -> String {
     if uri.starts_with("data:") || uri.contains("://") {
         return uri.to_string();
@@ -672,7 +648,7 @@ mod tests {
                 format: "glb".into(),
                 fingerprint: StaticMeshSourceFingerprint {
                     byte_len: 42,
-                    modified_unix_secs: 10,
+                    content_hash: "a".repeat(64),
                 },
                 dependencies: Vec::new(),
             },
@@ -741,6 +717,55 @@ mod tests {
         );
     }
 
+    #[test]
+    fn schema_v3_manifest_without_hash_migrates_to_content_fingerprint() {
+        let root = std::env::temp_dir().join(format!(
+            "blacksite-static-mesh-legacy-{}",
+            uuid::Uuid::new_v4()
+        ));
+        fs::create_dir_all(&root).unwrap();
+        let path = root.join("legacy.static_mesh.ron");
+        let expected = test_manifest();
+        let canonical =
+            ron::ser::to_string_pretty(&expected, ron::ser::PrettyConfig::default()).unwrap();
+        let legacy = canonical
+            .replacen("schema_version: 4", "schema_version: 3", 1)
+            .lines()
+            .filter(|line| !line.contains("content_hash:"))
+            .collect::<Vec<_>>()
+            .join("\n");
+        fs::write(&path, legacy).unwrap();
+
+        assert!(write_pretty_ron_if_changed(&path, &expected).unwrap());
+        assert_eq!(
+            load_static_mesh_manifest(&path.to_string_lossy()).unwrap(),
+            expected
+        );
+
+        fs::remove_dir_all(root).unwrap();
+    }
+
+    #[test]
+    fn equivalent_static_manifest_preserves_existing_formatting_and_newline() {
+        let root = std::env::temp_dir().join(format!(
+            "blacksite-static-mesh-semantic-{}",
+            uuid::Uuid::new_v4()
+        ));
+        fs::create_dir_all(&root).unwrap();
+        let path = root.join("stable.static_mesh.ron");
+        let manifest = test_manifest();
+        let exact = format!(
+            "{}\n\n",
+            ron::ser::to_string_pretty(&manifest, ron::ser::PrettyConfig::default()).unwrap()
+        );
+        fs::write(&path, &exact).unwrap();
+
+        assert!(!write_pretty_ron_if_changed(&path, &manifest).unwrap());
+        assert_eq!(fs::read_to_string(&path).unwrap(), exact);
+
+        fs::remove_dir_all(root).unwrap();
+    }
+
     #[test]
     fn renderer_from_manifest_can_ignore_source_materials() {
         let manifest = test_manifest();
@@ -785,6 +810,7 @@ mod tests {
             path,
             label: "Robot Expressive".into(),
             kind_tag: "Model".into(),
+            source_fingerprint: None,
             import_settings: ImportSettings::default(),
             dependencies: Vec::new(),
         };
diff --git a/crates/editor/src/ui/animation_inspector.rs b/crates/editor/src/ui/animation_inspector.rs
index 46db655..4c19765 100644
--- a/crates/editor/src/ui/animation_inspector.rs
+++ b/crates/editor/src/ui/animation_inspector.rs
@@ -884,7 +884,6 @@ mod tests {
                 format: "glb".into(),
                 fingerprint: AnimationSourceFingerprint {
                     byte_len: 42,
-                    modified_unix_secs: 1,
                     content_hash: "hash".into(),
                 },
                 dependencies: Vec::new(),
diff --git a/crates/game/src/animation.rs b/crates/game/src/animation.rs
index 5ae3d2c..200cac7 100644
--- a/crates/game/src/animation.rs
+++ b/crates/game/src/animation.rs
@@ -1267,7 +1267,6 @@ mod tests {
                 format: "glb".into(),
                 fingerprint: AnimationSourceFingerprint {
                     byte_len: 1,
-                    modified_unix_secs: 0,
                     content_hash: "fixture".into(),
                 },
                 dependencies: Vec::new(),
diff --git a/crates/scene/src/project_validation.rs b/crates/scene/src/project_validation.rs
index cd1c86f..0d05e34 100644
--- a/crates/scene/src/project_validation.rs
+++ b/crates/scene/src/project_validation.rs
@@ -9,12 +9,13 @@ use shared::{
     animation_clip_source_index, animation_clip_sub_asset_id, animation_skeleton_source_index,
     animation_skeleton_sub_asset_id,
     brush_math::{validate_brush, BrushDiagnosticSeverity},
-    AnimationControllerDesc, AnimationDiagnosticSeverity, AnimationManifest, AudioListenerDesc,
-    AudioSourceDesc, BrushDesc, ColliderDesc, ColliderShapeDesc, EditorAssetRef, MaterialAsset,
-    MaterialDesc, MaterialInstanceAsset, MaterialOverride, ModelRef, PostProcessEffectAsset,
-    PostProcessVolumeDesc, PrefabInstance, PrefabRef, RendererMaterialSet, ShaderSchemaAsset,
-    SkinnedMeshRenderer, StaticMeshRenderer, TerrainDesc, ANIMATION_MANIFEST_SCHEMA_VERSION,
-    AUDIO_CLIP_SUB_ASSET_ID, COMPONENT_ANIMATION_CONTROLLER_DESC, COMPONENT_SKINNED_MESH_RENDERER,
+    AnimationControllerDesc, AnimationDiagnosticSeverity, AnimationManifest,
+    AssetSourceFingerprint, AudioListenerDesc, AudioSourceDesc, BrushDesc, ColliderDesc,
+    ColliderShapeDesc, EditorAssetRef, MaterialAsset, MaterialDesc, MaterialInstanceAsset,
+    MaterialOverride, ModelRef, PostProcessEffectAsset, PostProcessVolumeDesc, PrefabInstance,
+    PrefabRef, RendererMaterialSet, ShaderSchemaAsset, SkinnedMeshRenderer, StaticMeshRenderer,
+    TerrainDesc, ANIMATION_MANIFEST_SCHEMA_VERSION, AUDIO_CLIP_SUB_ASSET_ID,
+    COMPONENT_ANIMATION_CONTROLLER_DESC, COMPONENT_SKINNED_MESH_RENDERER,
     NAVIGATION_GENERATED_ARTIFACT_DIRECTORY,
 };
 
@@ -322,6 +323,8 @@ struct RegistryAssetRecord {
     path: String,
     kind_tag: String,
     #[serde(default)]
+    source_fingerprint: Option<AssetSourceFingerprint>,
+    #[serde(default)]
     import_settings: RegistryImportSettings,
     #[serde(default)]
     dependencies: Vec<String>,
@@ -482,10 +485,96 @@ fn validate_asset_registry(
                 repair: "Convert the clip to Ogg Vorbis, WAV, MP3, or FLAC and reimport it.".into(),
             });
         }
+        if matches!(record.kind_tag.as_str(), "Model" | "Texture" | "AudioClip") {
+            validate_content_fingerprint(
+                project_root,
+                report,
+                "assets/.index/registry.ron",
+                &record.path,
+                record.source_fingerprint.as_ref(),
+                "registry.source_fingerprint_missing",
+                "registry.source_fingerprint_stale",
+                "registered imported source",
+            );
+        }
     }
     animation_catalog
 }
 
+#[allow(clippy::too_many_arguments)]
+fn validate_content_fingerprint(
+    project_root: &Path,
+    report: &mut ProjectValidationReport,
+    owner_path: &str,
+    source_path: &str,
+    fingerprint: Option<&AssetSourceFingerprint>,
+    missing_code: &str,
+    stale_code: &str,
+    source_label: &str,
+) {
+    let Some(fingerprint) = fingerprint.filter(|fingerprint| fingerprint.is_complete()) else {
+        report.findings.push(ProjectValidationFinding {
+            severity: ValidationSeverity::Error,
+            code: missing_code.into(),
+            source_path: owner_path.into(),
+            owner_actor_id: None,
+            reference: Some(source_path.into()),
+            message: format!("{source_label} has no complete BLAKE3 content fingerprint"),
+            repair: "Refresh the asset registry or reimport the source with this editor version."
+                .into(),
+        });
+        return;
+    };
+    let Some(path) = resolve_reference(project_root, source_path) else {
+        return;
+    };
+    let Ok(metadata) = std::fs::metadata(&path) else {
+        return;
+    };
+    if metadata.len() != fingerprint.byte_len {
+        report.findings.push(ProjectValidationFinding {
+            severity: ValidationSeverity::Error,
+            code: stale_code.into(),
+            source_path: owner_path.into(),
+            owner_actor_id: None,
+            reference: Some(source_path.into()),
+            message: format!(
+                "{source_label} size changed from {} to {} bytes",
+                fingerprint.byte_len,
+                metadata.len()
+            ),
+            repair: "Refresh or reimport the changed source before validation or packaging.".into(),
+        });
+        return;
+    }
+    match blake3_file_hash(&path) {
+        Ok(content_hash) if content_hash != fingerprint.content_hash => {
+            report.findings.push(ProjectValidationFinding {
+                severity: ValidationSeverity::Error,
+                code: stale_code.into(),
+                source_path: owner_path.into(),
+                owner_actor_id: None,
+                reference: Some(source_path.into()),
+                message: format!(
+                    "{source_label} content changed even though its byte length is unchanged"
+                ),
+                repair: "Refresh or reimport the changed source before validation or packaging."
+                    .into(),
+            });
+        }
+        Ok(_) => {}
+        Err(error) => report.findings.push(ProjectValidationFinding {
+            severity: ValidationSeverity::Error,
+            code: stale_code.into(),
+            source_path: owner_path.into(),
+            owner_actor_id: None,
+            reference: Some(source_path.into()),
+            message: format!("could not hash {source_label}: {error}"),
+            repair: "Restore readable source content and rerun validation.".into(),
+        }),
+    }
+}
+
 fn reference_is_runtime_package_asset(reference: &str) -> bool {
     let relative = Path::new(reference.split('#').next().unwrap_or(reference));
     if relative.is_absolute()
@@ -709,10 +798,12 @@ struct StaticMeshManifestView {
 struct StaticMeshSourceView {
     path: String,
     #[serde(default)]
+    fingerprint: AssetSourceFingerprint,
+    #[serde(default)]
     dependencies: Vec<String>,
 }
 
-const STATIC_MESH_MANIFEST_SCHEMA_VERSION: u32 = 3;
+const STATIC_MESH_MANIFEST_SCHEMA_VERSION: u32 = 4;
 
 fn validate_static_mesh_manifests(project_root: &Path, report: &mut ProjectValidationReport) {
     for path in ron_files(
@@ -754,6 +845,16 @@ fn validate_static_mesh_manifests(project_root: &Path, report: &mut ProjectValid
             "model",
             &manifest.source.path,
         );
+        validate_content_fingerprint(
+            project_root,
+            report,
+            &source,
+            &manifest.source.path,
+            Some(&manifest.source.fingerprint),
+            "static_mesh.manifest_fingerprint_missing",
+            "static_mesh.manifest_stale",
+            "static mesh source",
+        );
         for dependency in manifest.source.dependencies {
             add_reference(
                 project_root,
@@ -975,12 +1076,7 @@ fn validate_animation_manifest_contract(
     }
 
     let fingerprint = &manifest.source.fingerprint;
-    let hash_is_present = fingerprint.content_hash.len() == 64
-        && fingerprint
-            .content_hash
-            .bytes()
-            .all(|byte| byte.is_ascii_hexdigit());
-    if fingerprint.byte_len == 0 || fingerprint.modified_unix_secs == 0 || !hash_is_present {
+    if fingerprint.byte_len == 0 || !fingerprint.is_complete() {
         report.findings.push(ProjectValidationFinding {
             severity: ValidationSeverity::Error,
             code: "animation.manifest_fingerprint_missing".into(),
@@ -3071,7 +3167,7 @@ mod tests {
     }
 
     #[test]
-    fn static_mesh_manifest_schema_v3_is_current() {
+    fn static_mesh_manifest_schema_v4_is_current() {
         let root = fixture_root();
         let source_path = "assets/models/static.glb";
         std::fs::create_dir_all(root.join("assets/models")).unwrap();
@@ -3081,7 +3177,8 @@ mod tests {
         std::fs::write(
             artifact_dir.join("static-id.static_mesh.ron"),
             format!(
-                "(schema_version:{STATIC_MESH_MANIFEST_SCHEMA_VERSION},asset_id:\"static-id\",source:(path:\"{source_path}\",dependencies:[]),warnings:[])"
+                "(schema_version:{STATIC_MESH_MANIFEST_SCHEMA_VERSION},asset_id:\"static-id\",source:(path:\"{source_path}\",fingerprint:(byte_len:5,content_hash:\"{}\"),dependencies:[]),warnings:[])",
+                blake3::hash(b"model").to_hex()
             ),
         )
         .unwrap();
@@ -3095,6 +3192,70 @@ mod tests {
         std::fs::remove_dir_all(root).unwrap();
     }
 
+    #[test]
+    fn same_size_static_mesh_source_change_invalidates_content_hash() {
+        let root = fixture_root();
+        let source_path = "assets/models/static.glb";
+        std::fs::create_dir_all(root.join("assets/models")).unwrap();
+        std::fs::write(root.join(source_path), b"model").unwrap();
+        let fingerprint = AssetSourceFingerprint::from_bytes(b"model");
+        let artifact = root.join("assets/meshes/generated/static-id.static_mesh.ron");
+        std::fs::create_dir_all(artifact.parent().unwrap()).unwrap();
+        std::fs::write(
+            &artifact,
+            format!(
+                "(schema_version:{STATIC_MESH_MANIFEST_SCHEMA_VERSION},asset_id:\"static-id\",source:(path:\"{source_path}\",fingerprint:(byte_len:{},content_hash:\"{}\"),dependencies:[]),warnings:[])",
+                fingerprint.byte_len, fingerprint.content_hash
+            ),
+        )
+        .unwrap();
+        std::fs::write(root.join(source_path), b"modem").unwrap();
+
+        let report = validate_project(&root);
+
+        let finding = report
+            .findings
+            .iter()
+            .find(|finding| finding.code == "static_mesh.manifest_stale")
+            .expect("same-size model edit must stale the static mesh manifest");
+        assert!(finding.message.contains("byte length is unchanged"));
+        assert!(finding.repair.contains("Refresh") || finding.repair.contains("reimport"));
+        std::fs::remove_dir_all(root).unwrap();
+    }
+
+    #[test]
+    fn registry_detects_same_size_changes_for_all_imported_source_kinds() {
+        for (kind, relative) in [
+            ("Model", "assets/models/source.glb"),
+            ("Texture", "assets/textures/source.png"),
+            ("AudioClip", "assets/audio/source.ogg"),
+        ] {
+            let root = fixture_root();
+            let path = root.join(relative);
+            std::fs::create_dir_all(path.parent().unwrap()).unwrap();
+            std::fs::write(&path, b"source-a").unwrap();
+            let fingerprint = AssetSourceFingerprint::from_bytes(b"source-a");
+            std::fs::write(
+                root.join("assets/.index/registry.ron"),
+                format!(
+                    "[(id:(\"00000000-0000-0000-0000-000000000001\"),path:\"{relative}\",kind_tag:\"{kind}\",source_fingerprint:Some((byte_len:{},content_hash:\"{}\")),dependencies:[])]",
+                    fingerprint.byte_len, fingerprint.content_hash
+                ),
+            )
+            .unwrap();
+            std::fs::write(&path, b"source-b").unwrap();
+
+            let report = validate_project(&root);
+
+            assert!(report.findings.iter().any(|finding| {
+                finding.code == "registry.source_fingerprint_stale"
+                    && finding.reference.as_deref() == Some(relative)
+                    && finding.message.contains("byte length is unchanged")
+            }));
+            std::fs::remove_dir_all(root).unwrap();
+        }
+    }
+
     fn write_manifest(root: &Path, version: u32) {
         std::fs::write(
             root.join("assets/project.ron"),
@@ -3128,7 +3289,6 @@ mod tests {
                 format: source_format.into(),
                 fingerprint: AnimationSourceFingerprint {
                     byte_len: 5,
-                    modified_unix_secs: 1,
                     content_hash: blake3::hash(b"model").to_hex().to_string(),
                 },
                 dependencies: Vec::new(),
@@ -3188,10 +3348,12 @@ mod tests {
         let manifest = animation_manifest_path
             .map(|path| format!("Some({path:?})"))
             .unwrap_or_else(|| "None".into());
+        let fingerprint = AssetSourceFingerprint::from_bytes(b"model");
         std::fs::write(
             root.join("assets/.index/registry.ron"),
             format!(
-                "[(id:(\"{ANIMATION_ASSET_ID}\"),path:\"{source_path}\",kind_tag:\"Model\",import_settings:(static_mesh_manifest_path:None,animation_manifest_path:{manifest}),dependencies:[])]"
+                "[(id:(\"{ANIMATION_ASSET_ID}\"),path:\"{source_path}\",kind_tag:\"Model\",source_fingerprint:Some((byte_len:{},content_hash:\"{}\")),import_settings:(static_mesh_manifest_path:None,animation_manifest_path:{manifest}),dependencies:[])]",
+                fingerprint.byte_len, fingerprint.content_hash
             ),
         )
         .unwrap();
@@ -3205,10 +3367,12 @@ mod tests {
         let source = root.join(source_path);
         std::fs::create_dir_all(source.parent().unwrap()).unwrap();
         std::fs::write(source, b"model").unwrap();
+        let fingerprint = AssetSourceFingerprint::from_bytes(b"model");
         std::fs::write(
             root.join("assets/.index/registry.ron"),
             format!(
-                "[(id:(\"{ANIMATION_ASSET_ID}\"),path:\"{source_path}\",kind_tag:\"Model\",import_settings:(static_mesh_manifest_path:None,animation_manifest_path:Some(\"{ANIMATION_MANIFEST_PATH}\"),default_animation_clip_id:Some(\"{default_clip_id}\")),dependencies:[])]"
+                "[(id:(\"{ANIMATION_ASSET_ID}\"),path:\"{source_path}\",kind_tag:\"Model\",source_fingerprint:Some((byte_len:{},content_hash:\"{}\")),import_settings:(static_mesh_manifest_path:None,animation_manifest_path:Some(\"{ANIMATION_MANIFEST_PATH}\"),default_animation_clip_id:Some(\"{default_clip_id}\")),dependencies:[])]",
+                fingerprint.byte_len, fingerprint.content_hash
             ),
         )
         .unwrap();
@@ -3632,6 +3796,49 @@ mod tests {
         std::fs::remove_dir_all(root).unwrap();
     }
 
+    #[test]
+    fn project_validation_preserves_registry_and_generated_artifact_bytes() {
+        let root = fixture_root();
+        let source_path = "assets/models/hero.glb";
+        let manifest = animation_fixture_manifest(source_path, "glb", "rig-signature", true);
+        write_animation_source_and_registry(&root, source_path, Some(ANIMATION_MANIFEST_PATH));
+        write_animation_manifest(&root, &manifest);
+        write_animation_scene(&root, &animation_fixture_controller(&manifest));
+
+        let static_path = root.join("assets/meshes/generated/model-id.static_mesh.ron");
+        std::fs::create_dir_all(static_path.parent().unwrap()).unwrap();
+        std::fs::write(
+            &static_path,
+            format!(
+                "( schema_version: {STATIC_MESH_MANIFEST_SCHEMA_VERSION}, asset_id: \"model-id\", source: ( path: \"{source_path}\", fingerprint: ( byte_len: {}, content_hash: \"{}\", ), dependencies: [], ), warnings: [], )\n\n",
+                manifest.source.fingerprint.byte_len,
+                manifest.source.fingerprint.content_hash
+            ),
+        )
+        .unwrap();
+        let paths = [
+            root.join("assets/.index/registry.ron"),
+            root.join(ANIMATION_MANIFEST_PATH),
+            static_path,
+        ];
+        let before = paths
+            .iter()
+            .map(std::fs::read)
+            .collect::<Result<Vec<_>, _>>()
+            .unwrap();
+
+        let _ = validate_project(&root);
+        let _ = validate_project(&root);
+
+        let after = paths
+            .iter()
+            .map(std::fs::read)
+            .collect::<Result<Vec<_>, _>>()
+            .unwrap();
+        assert_eq!(after, before);
+        std::fs::remove_dir_all(root).unwrap();
+    }
+
     #[test]
     fn missing_animation_manifest_is_reported_globally_and_on_the_actor_property() {
         let root = fixture_root();
diff --git a/crates/shared/src/animation.rs b/crates/shared/src/animation.rs
index 2e8b5d5..17036e4 100644
--- a/crates/shared/src/animation.rs
+++ b/crates/shared/src/animation.rs
@@ -266,13 +266,8 @@ pub struct AnimationManifestSource {
     pub dependencies: Vec<String>,
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-pub struct AnimationSourceFingerprint {
-    pub byte_len: u64,
-    pub modified_unix_secs: u64,
-    /// BLAKE3 hash of the source file bytes.
-    pub content_hash: String,
-}
+/// Backward-compatible name for the shared imported-source fingerprint contract.
+pub type AnimationSourceFingerprint = crate::AssetSourceFingerprint;
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct AnimationSkeletonRecord {
diff --git a/crates/shared/src/asset_fingerprint.rs b/crates/shared/src/asset_fingerprint.rs
new file mode 100644
index 0000000..59b5635
--- /dev/null
+++ b/crates/shared/src/asset_fingerprint.rs
@@ -0,0 +1,50 @@
+use serde::{Deserialize, Serialize};
+
+/// Stable identity for the exact bytes of an imported project source.
+///
+/// Filesystem timestamps are deliberately excluded: Git and LFS do not preserve checkout mtimes,
+/// so they cannot participate in a portable authored-data contract.
+#[derive(Debug, Clone, Default, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub struct AssetSourceFingerprint {
+    pub byte_len: u64,
+    #[serde(default)]
+    pub content_hash: String,
+}
+
+impl AssetSourceFingerprint {
+    pub fn from_bytes(bytes: &[u8]) -> Self {
+        Self {
+            byte_len: bytes.len() as u64,
+            content_hash: blake3::hash(bytes).to_hex().to_string(),
+        }
+    }
+
+    pub fn is_complete(&self) -> bool {
+        self.content_hash.len() == 64
+            && self
+                .content_hash
+                .bytes()
+                .all(|byte| byte.is_ascii_digit() || (b'a'..=b'f').contains(&byte))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn exact_bytes_define_source_identity() {
+        let first = AssetSourceFingerprint::from_bytes(b"asset-a");
+        let same = AssetSourceFingerprint::from_bytes(b"asset-a");
+        let same_size_change = AssetSourceFingerprint::from_bytes(b"asset-b");
+
+        assert_eq!(first, same);
+        assert_ne!(first, same_size_change);
+        assert_eq!(first.byte_len, same_size_change.byte_len);
+        assert!(first.is_complete());
+
+        let mut noncanonical = first;
+        noncanonical.content_hash.make_ascii_uppercase();
+        assert!(!noncanonical.is_complete());
+    }
+}
diff --git a/crates/shared/src/lib.rs b/crates/shared/src/lib.rs
index c86f81c..360d6fe 100644
--- a/crates/shared/src/lib.rs
+++ b/crates/shared/src/lib.rs
@@ -6,6 +6,7 @@
 
 mod actor;
 mod animation;
+mod asset_fingerprint;
 pub mod brush_math;
 mod components;
 mod hydration;
@@ -18,6 +19,7 @@ mod rendering_profile_asset;
 
 pub use actor::{infer_actor_kind, validate_actor, ActorValidationError};
 pub use animation::*;
+pub use asset_fingerprint::AssetSourceFingerprint;
 pub use components::*;
 pub use hydration::{
     cascade_config_from_rendering, flush_level_object_hydration,
diff --git a/docs/README.md b/docs/README.md
index a6c902e..103d135 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -57,6 +57,7 @@ Immutable-style log of significant decisions. Add a new numbered ADR when changi
 | [0040](adr/0040-terrain-material-layer-weights.md) | Four-channel terrain material layers, compact normalized weights, and raster transport |
 | [0041](adr/0041-transactional-editor-physics-placement.md) | Paused editor physics ownership and transactional gravity placement |
 | [0042](adr/0042-guarded-editor-shutdown-and-document-savepoints.md) | Guarded native editor exit and canonical per-document clean checkpoints |
+| [0043](adr/0043-content-addressed-import-fingerprints.md) | Content-addressed imported-source identity and byte-preserving artifact publication |
 
 ## Editor framework
 
diff --git a/docs/adr/0017-normalized-static-mesh-assets.md b/docs/adr/0017-normalized-static-mesh-assets.md
index 8555ae5..2b0325c 100644
--- a/docs/adr/0017-normalized-static-mesh-assets.md
+++ b/docs/adr/0017-normalized-static-mesh-assets.md
@@ -13,7 +13,12 @@ retaining explicit, separate paths for skinned geometry and generic full-scene d
 
 ## Decision
 
-Model imports now generate deterministic project artifacts under `assets/meshes/generated/*.static_mesh.ron`. The artifact records stable part IDs, source path, format, source fingerprint, import settings, mesh/material subasset labels, source node/material metadata, dependency paths, and warnings for metadata that is not played by the static mesh path.
+Model imports now generate deterministic project artifacts under
+`assets/meshes/generated/*.static_mesh.ron`. The artifact records stable part IDs, source path,
+format, the content-addressed source fingerprint owned by
+[ADR 0043](0043-content-addressed-import-fingerprints.md), import settings, mesh/material subasset
+labels, source node/material metadata, dependency paths, and warnings for metadata that is not
+played by the static mesh path.
 
 The saved scene authoring component is `StaticMeshRenderer`. Its slots reference imported mesh/material assets by `EditorAssetRef` (`asset_id` + `sub_asset_id`) rather than source file paths. Hydration resolves those refs through the generated artifact, spawns runtime child `Mesh3d` parts, and strips/regenerates them like other hydrated ECS. Built-in primitives remain `Primitive`, and explicit full-scene placement remains `ImportedModel + ModelRef`.
 
@@ -35,4 +40,6 @@ Hierarchy mode is also stored per asset. `SingleActor` places all mesh parts int
 - Static mesh actors can expose renderer slots, source labels, shadows, collider policy, and material overrides in the inspector.
 - Skinned parts are marked in artifact schema v2 and excluded from static renderer construction and
   hydration. Animation playback uses the dedicated contract in ADRs 0031 and 0033.
+- Static-mesh schema v4 uses byte length plus BLAKE3 rather than checkout mtime, so a source touch is
+  a no-op while a same-size byte edit is detected.
 - Generated artifacts are project files but are hidden from the Asset Browser catalog to avoid treating them as levels/prefabs.
diff --git a/docs/adr/0028-authoritative-project-content-validation.md b/docs/adr/0028-authoritative-project-content-validation.md
index f554b11..9bdb78d 100644
--- a/docs/adr/0028-authoritative-project-content-validation.md
+++ b/docs/adr/0028-authoritative-project-content-validation.md
@@ -42,6 +42,12 @@ startup entrypoint. Unknown newer scene schemas are rejected rather than down-st
 requirements are explicit findings; for example, Solari projects record the required forward-path
 fallback QA when ray tracing is unavailable.
 
+Imported model, texture, and audio registry records, animation manifests, and static-mesh manifests
+share the content-addressed fingerprint contract in
+[ADR 0043](0043-content-addressed-import-fingerprints.md). Validation hashes source bytes and catches
+same-size changes without consulting mtimes. The validation entry point is read-only; CI asserts that
+running both level and sample validation leaves the checkout unchanged.
+
 Terrain descriptors participate in the same actor-owned dependency pass. Their authored dimensions,
 height and weight grids, chunk settings, base material, and material layers are validated before
 hydration so a sample or shipping scene cannot hide an invalid or unresolved terrain reference.
@@ -58,3 +64,5 @@ hydration so a sample or shipping scene cannot hide an invalid or unresolved ter
   editor UI and headless tooling consume the same scene ordering and validation result.
 - CI must hydrate Git LFS before validation because a pointer file is intentionally treated as
   missing runtime content.
+- Validators report stale or incomplete import fingerprints with repair guidance but never rewrite
+  the registry or generated artifacts.
diff --git a/docs/adr/0043-content-addressed-import-fingerprints.md b/docs/adr/0043-content-addressed-import-fingerprints.md
new file mode 100644
index 0000000..fc2b506
--- /dev/null
+++ b/docs/adr/0043-content-addressed-import-fingerprints.md
@@ -0,0 +1,55 @@
+# ADR 0043: Content-Addressed Import Fingerprints
+
+## Status
+
+Accepted
+
+## Context
+
+Generated model artifacts and the project asset registry must be stable across contributors, CI,
+Git worktrees, and LFS checkouts. Git does not preserve source-file modification times. Persisting a
+checkout mtime as source identity therefore caused the editor to rewrite otherwise equivalent
+animation and static-mesh manifests during startup. Static-mesh manifests also used only byte length
+and mtime, so a same-size source edit could evade the persisted identity contract.
+
+Formatting-only publication was a second source of noise. Re-serializing an equivalent RON
+document could normalize its final newline or layout even when import semantics had not changed.
+That made clean-checkout release evidence unreliable and obscured intentional asset edits.
+
+## Decision
+
+`shared::AssetSourceFingerprint` is the persisted imported-source identity. It contains the exact
+source byte length and lowercase BLAKE3 digest. Filesystem timestamps are not serialized or compared
+as semantic identity; an importer may use them only as an in-memory scan hint before confirming
+content.
+
+The asset registry stores this fingerprint for every imported model, texture, and audio source.
+Content identity also drives unique move reconciliation, so metadata-only drift cannot replace a
+stable registry UUID. Ambiguous copies still receive a new identity.
+
+Animation and static-mesh manifests use the same fingerprint. Animation schema v3 already contained
+a content hash, so its schema remains v3 and legacy `modified_unix_secs` fields are accepted as
+ignored unknown metadata. Static-mesh schema v4 replaces its length-plus-mtime record with length
+plus BLAKE3. Existing schema-v3 static artifacts are regenerated once; unrelated assets are not
+reimported.
+
+Registry and generated-manifest writers parse the existing RON and compare the semantic value before
+publication. Equivalent documents preserve their exact existing bytes, including layout and final
+newlines. Changed documents publish canonical pretty RON.
+
+Authoritative project validation remains read-only. It validates registry, animation, and
+static-mesh fingerprints by length and digest, including same-size source edits. CI runs both
+headless validators and then asserts that tracked and untracked checkout state is unchanged.
+
+## Consequences
+
+- A source touch or fresh checkout mtime cannot dirty the project.
+- Same-size source edits invalidate the affected registry/manifests deterministically.
+- Model, texture, and audio IDs survive uniquely identifiable moves by content.
+- Initial migration adds fingerprints to imported registry records and upgrades static manifests to
+  schema v4. Legacy animation files can remain byte-identical indefinitely because their timestamp
+  field is ignored.
+- Startup hashing reads imported source bytes. Future scan caches may use metadata to avoid work,
+  but they must verify content before persisting a changed identity.
+- External glTF/FBX dependency paths remain explicit manifest dependencies; extending fingerprints
+  to a dependency graph requires a separate versioned contract.
diff --git a/docs/editor/animation-authoring.md b/docs/editor/animation-authoring.md
index 2afe794..58c1849 100644
--- a/docs/editor/animation-authoring.md
+++ b/docs/editor/animation-authoring.md
@@ -68,10 +68,11 @@ serialize into authored scenes.
 
 `SkinnedMeshRenderer`, skeleton references, and clip references carry the model registry UUID. Generated
 artifacts are keyed by that UUID; source paths are cached resolution and repair hints. When one
-model is moved or renamed on disk, catalog refresh reconciles it by its animation-manifest content
-hash, preserves the UUID, and regenerates both manifests with the new source path. An identical copy
-is not treated as a move while the original still exists. Ambiguous content matches intentionally
-receive a new identity rather than silently binding the wrong asset.
+model is moved or renamed on disk, catalog refresh reconciles it by the registry's shared
+content-addressed source fingerprint, preserves the UUID, and regenerates both manifests with the
+new source path. The same registry policy covers textures and audio clips. An identical copy is not
+treated as a move while the original still exists. Ambiguous content matches intentionally receive
+a new identity rather than silently binding the wrong asset.
 
 Scene schema v3 migrates legacy animated actors that paired `ModelRef` with
 `AnimationControllerDesc` to the dedicated skinned renderer. Generic `ImportedModel + ModelRef`
@@ -83,6 +84,12 @@ used as identity. Animation-manifest schema v1 artifacts must be reimported to g
 signatures; schema v3 adds the explicit default-clip ID. Schema v2 deserializes as Imported rest
 pose and never receives an inferred default.
 
+Source identity uses exact byte length plus BLAKE3 and never checkout mtime. Existing animation
+schema-v3 files may retain a legacy `modified_unix_secs` field in their exact bytes; the current
+reader ignores it, and an equivalent refresh preserves the whole file unchanged. Static-mesh schema
+v4 uses the same content fingerprint. See
+[ADR 0043](../adr/0043-content-addressed-import-fingerprints.md).
+
 ## Validation And Format Boundary
 
 Interactive diagnostics and `cargo validate-levels` resolve registry UUIDs, generated manifests,
diff --git a/docs/editor/architecture.md b/docs/editor/architecture.md
index ca3d3c6..719d51f 100644
--- a/docs/editor/architecture.md
+++ b/docs/editor/architecture.md
@@ -224,7 +224,11 @@ the Edit-to-Play boundary restore the complete runtime snapshot. See
 - **Processing:** the asset registry generates normalized model manifests under
   `assets/meshes/generated/`. The manifests store stable part IDs, glTF/FBX mesh/material subasset
   labels, whether each part is skin-bound, source metadata, dependencies, and import settings.
-  These artifacts are hidden from the Asset Browser catalog.
+  Model, texture, and audio registry records use byte length plus BLAKE3 source identity; model
+  manifests use the same policy. Semantic RON comparison preserves exact existing bytes for an
+  equivalent refresh, so checkout mtimes and formatting do not dirty project content. See
+  [ADR 0043](../adr/0043-content-addressed-import-fingerprints.md). These artifacts are hidden from
+  the Asset Browser catalog.
 - **Browser subassets:** model rows can expand into a content shelf backed by the generated
   manifest. Unrigged mesh subassets place as independent `StaticMeshRenderer` actors. A skinned
   subasset places its owning source through `SkinnedMeshRenderer`, retaining joints and inverse bind
diff --git a/docs/editor/release-notes.md b/docs/editor/release-notes.md
index 9fabf4c..4b0cf0c 100644
--- a/docs/editor/release-notes.md
+++ b/docs/editor/release-notes.md
@@ -2,7 +2,8 @@
 
 ## Shipped
 
-- Stable asset registry (`assets/.index/registry.ron`) with import settings
+- Stable asset registry (`assets/.index/registry.ron`) with import settings and content-addressed
+  model/texture/audio source fingerprints
 - Prefab instances (`PrefabInstance`) + save-as-prefab workflow
 - Unsaved-scene guards on New/Open/Recent
 - Hierarchy additive select, reparent/unparent undo, multi-entity gizmo delta