diff --git a/packages/nylas-api/routes/threads.js b/packages/nylas-api/routes/threads.js
index a80fe76f1..661789457 100644
--- a/packages/nylas-api/routes/threads.js
+++ b/packages/nylas-api/routes/threads.js
@@ -89,6 +89,8 @@ module.exports = (server) => {
               { role: query.in },
             ]},
           });
+        } else {
+          include.push({model: Category})
         }
 
         Thread.findAll({
diff --git a/packages/nylas-core/database-connector.js b/packages/nylas-core/database-connector.js
index 2c09ea79d..4c0e7e6ea 100644
--- a/packages/nylas-core/database-connector.js
+++ b/packages/nylas-core/database-connector.js
@@ -3,6 +3,7 @@ const fs = require('fs');
 const path = require('path');
 const HookTransactionLog = require('./hook-transaction-log');
 const HookAccountCRUD = require('./hook-account-crud');
+const HookIncrementVersionOnSave = require('./hook-increment-version-on-save');
 
 require('./database-extensions'); // Extends Sequelize on require
 
@@ -46,12 +47,13 @@ class DatabaseConnector {
     const modelsPath = path.join(__dirname, 'models/account');
     const db = this._readModelsInDirectory(sequelize, modelsPath)
 
+    HookTransactionLog(db, sequelize);
+    HookIncrementVersionOnSave(db, sequelize);
+
     db.sequelize = sequelize;
     db.Sequelize = Sequelize;
     db.accountId = accountId;
 
-    HookTransactionLog(db, sequelize);
-
     return sequelize.authenticate().then(() =>
       sequelize.sync()
     ).thenReturn(db);
@@ -72,11 +74,11 @@ class DatabaseConnector {
     const modelsPath = path.join(__dirname, 'models/shared');
     const db = this._readModelsInDirectory(sequelize, modelsPath)
 
+    HookAccountCRUD(db, sequelize);
+
     db.sequelize = sequelize;
     db.Sequelize = Sequelize;
 
-    HookAccountCRUD(db, sequelize);
-
     return sequelize.authenticate().then(() =>
       sequelize.sync()
     ).thenReturn(db);
diff --git a/packages/nylas-core/hook-account-crud.js b/packages/nylas-core/hook-account-crud.js
index 0ded2094e..9f828b341 100644
--- a/packages/nylas-core/hook-account-crud.js
+++ b/packages/nylas-core/hook-account-crud.js
@@ -7,7 +7,7 @@ module.exports = (db, sequelize) => {
       PubsubConnector.broadcastClient().lpushAsync('accounts:unclaimed', dataValues.id);
       PubsubConnector.notify({
         accountId: dataValues.id,
-        type: MessageTypes.ACCOUNT_UPDATED
+        type: MessageTypes.ACCOUNT_UPDATED,
       });
     }
   })
@@ -15,7 +15,7 @@ module.exports = (db, sequelize) => {
     if ($modelOptions.name.singular === 'Account') {
       PubsubConnector.notify({
         accountId: dataValues.id,
-        type: MessageTypes.ACCOUNT_UPDATED
+        type: MessageTypes.ACCOUNT_UPDATED,
       });
     }
   })
diff --git a/packages/nylas-core/hook-increment-version-on-save.js b/packages/nylas-core/hook-increment-version-on-save.js
new file mode 100644
index 000000000..3751d0fcf
--- /dev/null
+++ b/packages/nylas-core/hook-increment-version-on-save.js
@@ -0,0 +1,13 @@
+
+module.exports = (db) => {
+  for (const modelName of Object.keys(db)) {
+    const model = db[modelName];
+
+    model.beforeCreate('increment-version-c', (instance) => {
+      instance.version = 1;
+    });
+    model.beforeUpdate('increment-version-u', (instance) => {
+      instance.version = instance.version ? instance.version + 1 : 1;
+    });
+  }
+}
diff --git a/packages/nylas-core/models/account/category.js b/packages/nylas-core/models/account/category.js
index 995622fc6..be7795ae1 100644
--- a/packages/nylas-core/models/account/category.js
+++ b/packages/nylas-core/models/account/category.js
@@ -3,6 +3,7 @@ const {JSONType} = require('../../database-types');
 module.exports = (sequelize, Sequelize) => {
   const Category = sequelize.define('category', {
     accountId: { type: Sequelize.STRING, allowNull: false },
+    version: Sequelize.INTEGER,
     name: Sequelize.STRING,
     role: Sequelize.STRING,
     type: Sequelize.ENUM('folder', 'label'),
diff --git a/packages/nylas-core/models/account/file.js b/packages/nylas-core/models/account/file.js
index 3cc619b39..8655189df 100644
--- a/packages/nylas-core/models/account/file.js
+++ b/packages/nylas-core/models/account/file.js
@@ -1,6 +1,7 @@
 module.exports = (sequelize, Sequelize) => {
   const File = sequelize.define('file', {
     accountId: { type: Sequelize.STRING, allowNull: false },
+    version: Sequelize.INTEGER,
     filename: Sequelize.STRING,
     contentId: Sequelize.STRING,
     contentType: Sequelize.STRING,
diff --git a/packages/nylas-core/models/account/message.js b/packages/nylas-core/models/account/message.js
index e9295900f..f7cba8982 100644
--- a/packages/nylas-core/models/account/message.js
+++ b/packages/nylas-core/models/account/message.js
@@ -7,6 +7,7 @@ const {JSONType, JSONARRAYType} = require('../../database-types');
 module.exports = (sequelize, Sequelize) => {
   const Message = sequelize.define('message', {
     accountId: { type: Sequelize.STRING, allowNull: false },
+    version: Sequelize.INTEGER,
     messageId: Sequelize.STRING,
     body: Sequelize.STRING,
     headers: JSONType('headers'),
diff --git a/packages/nylas-core/models/account/thread.js b/packages/nylas-core/models/account/thread.js
index fd1fc1f6a..d4c305eb2 100644
--- a/packages/nylas-core/models/account/thread.js
+++ b/packages/nylas-core/models/account/thread.js
@@ -3,6 +3,7 @@ const {JSONARRAYType} = require('../../database-types');
 module.exports = (sequelize, Sequelize) => {
   const Thread = sequelize.define('thread', {
     accountId: { type: Sequelize.STRING, allowNull: false },
+    version: Sequelize.INTEGER,
     threadId: Sequelize.STRING,
     subject: Sequelize.STRING,
     snippet: Sequelize.STRING,
@@ -22,9 +23,16 @@ module.exports = (sequelize, Sequelize) => {
     },
     instanceMethods: {
       toJSON: function toJSON() {
+        if (!this.categories) {
+          throw new Error("Thread.toJSON called on a thread where categories were not eagerly loaded.")
+        }
+        const folders = this.categories.filter(c => c.type === 'folder');
+        const labels = this.categories.filter(c => c.type === 'label');
         return {
           id: this.id,
           object: 'thread',
+          folders: folders,
+          labels: labels,
           account_id: this.accountId,
           participants: this.participants,
           subject: this.subject,