diff --git a/.changeset/fix-offline-mutations-changes-field.md b/.changeset/fix-offline-mutations-changes-field.md
new file mode 100644
index 000000000..8fc9eb37f
--- /dev/null
+++ b/.changeset/fix-offline-mutations-changes-field.md
@@ -0,0 +1,5 @@
+---
+'@tanstack/offline-transactions': patch
+---
+
+Fix mutation.changes field being lost during offline transaction serialization. Previously, the changes field was not included in serialized mutations, causing it to be empty ({}) after app restart. This led to sync functions receiving incomplete data when using mutation.changes for partial updates.
diff --git a/.claude/settings.local.json b/.claude/settings.local.json
new file mode 100644
index 000000000..f3509559e
--- /dev/null
+++ b/.claude/settings.local.json
@@ -0,0 +1,5 @@
+{
+  "permissions": {
+    "allow": ["Bash(git checkout:*)", "Bash(npx sherif:*)"]
+  }
+}
diff --git a/.tool-versions b/.tool-versions
new file mode 100644
index 000000000..0bfe39ff1
--- /dev/null
+++ b/.tool-versions
@@ -0,0 +1,2 @@
+pnpm 10.26.0
+nodejs 22.13.1
diff --git a/packages/db-collections/package.json b/packages/db-collections/package.json
new file mode 100644
index 000000000..074afba15
--- /dev/null
+++ b/packages/db-collections/package.json
@@ -0,0 +1,5 @@
+{
+  "name": "db-collections",
+  "version": "0.0.0",
+  "private": true
+}
diff --git a/packages/offline-transactions/src/outbox/TransactionSerializer.ts b/packages/offline-transactions/src/outbox/TransactionSerializer.ts
index 92142010f..67a62d41f 100644
--- a/packages/offline-transactions/src/outbox/TransactionSerializer.ts
+++ b/packages/offline-transactions/src/outbox/TransactionSerializer.ts
@@ -66,6 +66,7 @@ export class TransactionSerializer {
       type: mutation.type,
       modified: this.serializeValue(mutation.modified),
       original: this.serializeValue(mutation.original),
+      changes: this.serializeValue(mutation.changes),
       collectionId: registryKey, // Store registry key instead of collection.id
     }
   }
@@ -83,11 +84,11 @@ export class TransactionSerializer {
       type: data.type as any,
       modified: this.deserializeValue(data.modified),
       original: this.deserializeValue(data.original),
+      changes: this.deserializeValue(data.changes) ?? {},
       collection,
       // These fields would need to be reconstructed by the executor
       mutationId: ``, // Will be regenerated
       key: null, // Will be extracted from the data
-      changes: {}, // Will be recalculated
       metadata: undefined,
       syncMetadata: {},
       optimistic: true,
@@ -108,7 +109,7 @@ export class TransactionSerializer {
     if (typeof value === `object`) {
       const result: any = Array.isArray(value) ? [] : {}
       for (const key in value) {
-        if (value.hasOwnProperty(key)) {
+        if (Object.prototype.hasOwnProperty.call(value, key)) {
           result[key] = this.serializeValue(value[key])
         }
       }
@@ -139,7 +140,7 @@ export class TransactionSerializer {
     if (typeof value === `object`) {
       const result: any = Array.isArray(value) ? [] : {}
       for (const key in value) {
-        if (value.hasOwnProperty(key)) {
+        if (Object.prototype.hasOwnProperty.call(value, key)) {
           result[key] = this.deserializeValue(value[key])
         }
       }
diff --git a/packages/offline-transactions/src/types.ts b/packages/offline-transactions/src/types.ts
index 9221e323a..e0b1f6df7 100644
--- a/packages/offline-transactions/src/types.ts
+++ b/packages/offline-transactions/src/types.ts
@@ -21,6 +21,7 @@ export interface SerializedMutation {
   type: string
   modified: any
   original: any
+  changes: any
   collectionId: string
 }
 
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index a7b7a4ae4..f415ce675 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -842,6 +842,8 @@ importers:
         specifier: ^3.2.4
         version: 3.2.4(@types/debug@4.1.12)(@types/node@24.7.0)(@vitest/ui@3.2.4(vitest@3.2.4))(jiti@2.6.1)(jsdom@27.4.0)(lightningcss@1.30.2)(sass@1.90.0)(terser@5.44.0)(tsx@4.21.0)(yaml@2.8.1)
 
+  packages/db-collections: {}
+
   packages/db-ivm:
     dependencies:
       fractional-indexing: