diff --git a/crates/ely_browser_core/src/lib.rs b/crates/ely_browser_core/src/lib.rs
index 1290db3..861be42 100644
--- a/crates/ely_browser_core/src/lib.rs
+++ b/crates/ely_browser_core/src/lib.rs
@@ -2,6 +2,7 @@ mod error;
 mod navigation;
 mod state;
 mod sync_engine;
+mod sync_records;
 
 pub use error::CoreError;
 pub use state::{
diff --git a/crates/ely_browser_core/src/state/sync.rs b/crates/ely_browser_core/src/state/sync.rs
index 22c4d12..2f130b8 100644
--- a/crates/ely_browser_core/src/state/sync.rs
+++ b/crates/ely_browser_core/src/state/sync.rs
@@ -8,9 +8,8 @@ use ely_domain::{
 use ely_sync_client::SyncClientError;
 
 use super::BrowserCore;
-use crate::sync_engine::{
-    BookmarkSyncRecord, SpaceSyncRecord, SyncSnapshotApplySummary, SyncSnapshotBody, TabSyncRecord,
-};
+use crate::sync_engine::SyncSnapshotApplySummary;
+use crate::sync_records::{BookmarkSyncRecord, SpaceSyncRecord, SyncSnapshotBody, TabSyncRecord};
 
 #[derive(Clone, Debug)]
 pub(super) struct SyncObjectPolicies {
diff --git a/crates/ely_browser_core/src/sync_engine.rs b/crates/ely_browser_core/src/sync_engine.rs
index 8e539a9..b8aa370 100644
--- a/crates/ely_browser_core/src/sync_engine.rs
+++ b/crates/ely_browser_core/src/sync_engine.rs
@@ -3,14 +3,13 @@ use std::{
     time::{SystemTime, UNIX_EPOCH},
 };
 
-use ely_domain::{ArchivePolicy, BookmarkEntry, BrowserTab, Space, TabFlags};
 use ely_sync_client::{
     ApiClientConfig, BearerToken, BearerTokenStore, DeviceIdentity, SnapshotPayload,
     SnapshotUploadRequest, SyncApiClient, SyncClientError, SyncLatestSnapshotDocument,
 };
-use serde::{Deserialize, Serialize};
 
 use crate::state::BrowserCore;
+use crate::sync_records::{SNAPSHOT_SCHEMA_REV, SyncSnapshotBody};
 
 /// Per-profile sync engine for device identity, bearer-token storage, and snapshot IO.
 #[derive(Debug)]
@@ -261,8 +260,6 @@ impl SyncSnapshotApplySummary {
     }
 }
 
-const SNAPSHOT_SCHEMA_REV: u32 = 1;
-
 fn current_logical_clock() -> u64 {
     SystemTime::now().duration_since(UNIX_EPOCH).map(|elapsed| elapsed.as_secs()).unwrap_or(0)
 }
@@ -275,186 +272,6 @@ fn device_registration_idempotency_key(identity: &DeviceIdentity) -> String {
     format!("device-register:{}", identity.device_id)
 }
 
-#[derive(Serialize, Deserialize)]
-pub(crate) struct SyncSnapshotBody {
-    pub(crate) schema_rev: u32,
-    #[serde(default)]
-    pub(crate) spaces: Vec<SpaceSyncRecord>,
-    pub(crate) bookmarks: Vec<BookmarkSyncRecord>,
-    #[serde(default)]
-    pub(crate) tabs: Vec<TabSyncRecord>,
-}
-
-impl SyncSnapshotBody {
-    fn from_core(core: &BrowserCore) -> Self {
-        Self {
-            schema_rev: SNAPSHOT_SCHEMA_REV,
-            spaces: core
-                .visible_spaces_for_sync()
-                .into_iter()
-                .map(SpaceSyncRecord::from_space)
-                .collect(),
-            bookmarks: core
-                .visible_bookmarks_for_sync()
-                .into_iter()
-                .map(|entry| {
-                    BookmarkSyncRecord::from_entry(
-                        entry,
-                        core.sync_space_name_for(entry.space_id()),
-                    )
-                })
-                .collect(),
-            tabs: core
-                .visible_tabs_for_sync()
-                .into_iter()
-                .map(|entry| {
-                    TabSyncRecord::from_entry(entry, core.sync_space_name_for(entry.space_id()))
-                })
-                .collect(),
-        }
-    }
-}
-
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub(crate) struct SpaceSyncRecord {
-    pub(crate) id: String,
-    pub(crate) name: String,
-    pub(crate) icon: String,
-    pub(crate) accent_hex: u32,
-    pub(crate) default_profile_id: String,
-    pub(crate) archive_policy: SpaceArchivePolicySyncRecord,
-    pub(crate) sidebar_width_px: u16,
-    pub(crate) sort_key: u64,
-}
-
-impl SpaceSyncRecord {
-    fn from_space(space: &Space) -> Self {
-        Self {
-            id: space.id().as_str().to_string(),
-            name: space.name().to_string(),
-            icon: space.icon().to_string(),
-            accent_hex: space.accent_hex(),
-            default_profile_id: space.default_profile_id().as_str().to_string(),
-            archive_policy: SpaceArchivePolicySyncRecord::from(space.archive_policy()),
-            sidebar_width_px: space.sidebar_width_px(),
-            sort_key: space.sort_key(),
-        }
-    }
-}
-
-#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
-#[serde(tag = "kind", rename_all = "snake_case")]
-pub(crate) enum SpaceArchivePolicySyncRecord {
-    Manual,
-    IdleDays { days: u16 },
-}
-
-impl From<&ArchivePolicy> for SpaceArchivePolicySyncRecord {
-    fn from(policy: &ArchivePolicy) -> Self {
-        match policy {
-            ArchivePolicy::Manual => Self::Manual,
-            ArchivePolicy::IdleDays(days) => Self::IdleDays { days: *days },
-        }
-    }
-}
-
-impl From<SpaceArchivePolicySyncRecord> for ArchivePolicy {
-    fn from(policy: SpaceArchivePolicySyncRecord) -> Self {
-        match policy {
-            SpaceArchivePolicySyncRecord::Manual => Self::Manual,
-            SpaceArchivePolicySyncRecord::IdleDays { days } => Self::IdleDays(days),
-        }
-    }
-}
-
-/// Wire representation of a bookmark with default-fill fields for older snapshots.
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub(crate) struct BookmarkSyncRecord {
-    pub(crate) id: String,
-    pub(crate) title: String,
-    pub(crate) url: String,
-    pub(crate) profile_id: String,
-    pub(crate) space_id: String,
-    #[serde(default)]
-    pub(crate) space_name: Option<String>,
-    pub(crate) collection_name: String,
-    pub(crate) tags: Vec<String>,
-    pub(crate) note: Option<String>,
-    #[serde(default)]
-    pub(crate) thumbnail_key: Option<String>,
-    pub(crate) added_at_secs: u64,
-}
-
-impl BookmarkSyncRecord {
-    fn from_entry(entry: &BookmarkEntry, space_name: Option<String>) -> Self {
-        Self {
-            id: entry.id().as_str().to_string(),
-            title: entry.title().to_string(),
-            url: entry.url().as_str().to_string(),
-            profile_id: entry.profile_id().as_str().to_string(),
-            space_id: entry.space_id().as_str().to_string(),
-            space_name,
-            collection_name: entry.collection_name().to_string(),
-            tags: entry.tags().to_vec(),
-            note: entry.note().map(str::to_string),
-            thumbnail_key: entry.thumbnail_key().map(str::to_string),
-            added_at_secs: system_time_secs(entry.added_at()),
-        }
-    }
-}
-
-/// Wire representation of an open tab. The record carries only
-/// user-visible tab state; runtime-only fields such as split layout
-/// membership and crash state stay local to the receiving device.
-#[derive(Clone, Debug, Serialize, Deserialize)]
-pub(crate) struct TabSyncRecord {
-    pub(crate) id: String,
-    pub(crate) title: String,
-    pub(crate) url: String,
-    pub(crate) profile_id: String,
-    pub(crate) space_id: String,
-    #[serde(default)]
-    pub(crate) space_name: Option<String>,
-    #[serde(default)]
-    pub(crate) favicon_key: Option<String>,
-    #[serde(default)]
-    pub(crate) flags: TabFlags,
-    pub(crate) sort_key: u64,
-    #[serde(default = "default_sync_enabled")]
-    pub(crate) sync_enabled: bool,
-    pub(crate) zoom_percent: u16,
-    pub(crate) created_at_secs: u64,
-    pub(crate) last_active_at_secs: u64,
-}
-
-impl TabSyncRecord {
-    fn from_entry(entry: &BrowserTab, space_name: Option<String>) -> Self {
-        Self {
-            id: entry.id().as_str().to_string(),
-            title: entry.title().to_string(),
-            url: entry.url().as_str().to_string(),
-            profile_id: entry.profile_id().as_str().to_string(),
-            space_id: entry.space_id().as_str().to_string(),
-            space_name,
-            favicon_key: entry.favicon_key().map(str::to_string),
-            flags: entry.flags().clone(),
-            sort_key: entry.sort_key(),
-            sync_enabled: entry.sync_enabled(),
-            zoom_percent: entry.zoom_percent(),
-            created_at_secs: system_time_secs(entry.created_at()),
-            last_active_at_secs: system_time_secs(entry.last_active_at()),
-        }
-    }
-}
-
-fn default_sync_enabled() -> bool {
-    true
-}
-
-fn system_time_secs(time: SystemTime) -> u64 {
-    time.duration_since(UNIX_EPOCH).map(|elapsed| elapsed.as_secs()).unwrap_or(0)
-}
-
 #[derive(Debug)]
 pub struct SyncEngineBuilder {
     pub profile_data_dir: PathBuf,
diff --git a/crates/ely_browser_core/src/sync_records.rs b/crates/ely_browser_core/src/sync_records.rs
new file mode 100644
index 0000000..5809ca2
--- /dev/null
+++ b/crates/ely_browser_core/src/sync_records.rs
@@ -0,0 +1,184 @@
+use std::time::{SystemTime, UNIX_EPOCH};
+
+use ely_domain::{ArchivePolicy, BookmarkEntry, BrowserTab, Space, TabFlags};
+use serde::{Deserialize, Serialize};
+
+use crate::state::BrowserCore;
+
+pub(crate) const SNAPSHOT_SCHEMA_REV: u32 = 1;
+
+#[derive(Serialize, Deserialize)]
+pub(crate) struct SyncSnapshotBody {
+    pub(crate) schema_rev: u32,
+    #[serde(default)]
+    pub(crate) spaces: Vec<SpaceSyncRecord>,
+    pub(crate) bookmarks: Vec<BookmarkSyncRecord>,
+    #[serde(default)]
+    pub(crate) tabs: Vec<TabSyncRecord>,
+}
+
+impl SyncSnapshotBody {
+    pub(crate) fn from_core(core: &BrowserCore) -> Self {
+        Self {
+            schema_rev: SNAPSHOT_SCHEMA_REV,
+            spaces: core
+                .visible_spaces_for_sync()
+                .into_iter()
+                .map(SpaceSyncRecord::from_space)
+                .collect(),
+            bookmarks: core
+                .visible_bookmarks_for_sync()
+                .into_iter()
+                .map(|entry| {
+                    BookmarkSyncRecord::from_entry(
+                        entry,
+                        core.sync_space_name_for(entry.space_id()),
+                    )
+                })
+                .collect(),
+            tabs: core
+                .visible_tabs_for_sync()
+                .into_iter()
+                .map(|entry| {
+                    TabSyncRecord::from_entry(entry, core.sync_space_name_for(entry.space_id()))
+                })
+                .collect(),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub(crate) struct SpaceSyncRecord {
+    pub(crate) id: String,
+    pub(crate) name: String,
+    pub(crate) icon: String,
+    pub(crate) accent_hex: u32,
+    pub(crate) default_profile_id: String,
+    pub(crate) archive_policy: SpaceArchivePolicySyncRecord,
+    pub(crate) sidebar_width_px: u16,
+    pub(crate) sort_key: u64,
+}
+
+impl SpaceSyncRecord {
+    fn from_space(space: &Space) -> Self {
+        Self {
+            id: space.id().as_str().to_string(),
+            name: space.name().to_string(),
+            icon: space.icon().to_string(),
+            accent_hex: space.accent_hex(),
+            default_profile_id: space.default_profile_id().as_str().to_string(),
+            archive_policy: SpaceArchivePolicySyncRecord::from(space.archive_policy()),
+            sidebar_width_px: space.sidebar_width_px(),
+            sort_key: space.sort_key(),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
+#[serde(tag = "kind", rename_all = "snake_case")]
+pub(crate) enum SpaceArchivePolicySyncRecord {
+    Manual,
+    IdleDays { days: u16 },
+}
+
+impl From<&ArchivePolicy> for SpaceArchivePolicySyncRecord {
+    fn from(policy: &ArchivePolicy) -> Self {
+        match policy {
+            ArchivePolicy::Manual => Self::Manual,
+            ArchivePolicy::IdleDays(days) => Self::IdleDays { days: *days },
+        }
+    }
+}
+
+impl From<SpaceArchivePolicySyncRecord> for ArchivePolicy {
+    fn from(policy: SpaceArchivePolicySyncRecord) -> Self {
+        match policy {
+            SpaceArchivePolicySyncRecord::Manual => Self::Manual,
+            SpaceArchivePolicySyncRecord::IdleDays { days } => Self::IdleDays(days),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub(crate) struct BookmarkSyncRecord {
+    pub(crate) id: String,
+    pub(crate) title: String,
+    pub(crate) url: String,
+    pub(crate) profile_id: String,
+    pub(crate) space_id: String,
+    #[serde(default)]
+    pub(crate) space_name: Option<String>,
+    pub(crate) collection_name: String,
+    pub(crate) tags: Vec<String>,
+    pub(crate) note: Option<String>,
+    #[serde(default)]
+    pub(crate) thumbnail_key: Option<String>,
+    pub(crate) added_at_secs: u64,
+}
+
+impl BookmarkSyncRecord {
+    fn from_entry(entry: &BookmarkEntry, space_name: Option<String>) -> Self {
+        Self {
+            id: entry.id().as_str().to_string(),
+            title: entry.title().to_string(),
+            url: entry.url().as_str().to_string(),
+            profile_id: entry.profile_id().as_str().to_string(),
+            space_id: entry.space_id().as_str().to_string(),
+            space_name,
+            collection_name: entry.collection_name().to_string(),
+            tags: entry.tags().to_vec(),
+            note: entry.note().map(str::to_string),
+            thumbnail_key: entry.thumbnail_key().map(str::to_string),
+            added_at_secs: system_time_secs(entry.added_at()),
+        }
+    }
+}
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub(crate) struct TabSyncRecord {
+    pub(crate) id: String,
+    pub(crate) title: String,
+    pub(crate) url: String,
+    pub(crate) profile_id: String,
+    pub(crate) space_id: String,
+    #[serde(default)]
+    pub(crate) space_name: Option<String>,
+    #[serde(default)]
+    pub(crate) favicon_key: Option<String>,
+    #[serde(default)]
+    pub(crate) flags: TabFlags,
+    pub(crate) sort_key: u64,
+    #[serde(default = "default_sync_enabled")]
+    pub(crate) sync_enabled: bool,
+    pub(crate) zoom_percent: u16,
+    pub(crate) created_at_secs: u64,
+    pub(crate) last_active_at_secs: u64,
+}
+
+impl TabSyncRecord {
+    fn from_entry(entry: &BrowserTab, space_name: Option<String>) -> Self {
+        Self {
+            id: entry.id().as_str().to_string(),
+            title: entry.title().to_string(),
+            url: entry.url().as_str().to_string(),
+            profile_id: entry.profile_id().as_str().to_string(),
+            space_id: entry.space_id().as_str().to_string(),
+            space_name,
+            favicon_key: entry.favicon_key().map(str::to_string),
+            flags: entry.flags().clone(),
+            sort_key: entry.sort_key(),
+            sync_enabled: entry.sync_enabled(),
+            zoom_percent: entry.zoom_percent(),
+            created_at_secs: system_time_secs(entry.created_at()),
+            last_active_at_secs: system_time_secs(entry.last_active_at()),
+        }
+    }
+}
+
+fn default_sync_enabled() -> bool {
+    true
+}
+
+fn system_time_secs(time: SystemTime) -> u64 {
+    time.duration_since(UNIX_EPOCH).map(|elapsed| elapsed.as_secs()).unwrap_or(0)
+}