diff --git a/packages/client-app/src/flux/mailsync-bridge.es6 b/packages/client-app/src/flux/mailsync-bridge.es6
index ce9b35480..64b4cd4cf 100644
--- a/packages/client-app/src/flux/mailsync-bridge.es6
+++ b/packages/client-app/src/flux/mailsync-bridge.es6
@@ -72,8 +72,6 @@ export default class MailsyncBridge {
     }
 
     task.validate();
-
-    task.sequentialId = ++this._currentSequentialId;
     task.status = 'local';
     this.sendMessageToAccount(task.accountId, {type: 'task-queued', task: task});
   }
diff --git a/packages/client-app/src/flux/models/category.es6 b/packages/client-app/src/flux/models/category.es6
index dfbb0bbc3..fde541e71 100644
--- a/packages/client-app/src/flux/models/category.es6
+++ b/packages/client-app/src/flux/models/category.es6
@@ -88,9 +88,6 @@ export default class Category extends Model {
     localStatus: Attributes.Object({
       modelKey: 'localStatus',
     }),
-    _refcount: Attributes.Number({
-      modelKey: '_refcount',
-    }),
   });
 
   static Types = {
diff --git a/packages/client-app/src/flux/models/message.es6 b/packages/client-app/src/flux/models/message.es6
index 538637ef1..5b6421ef8 100644
--- a/packages/client-app/src/flux/models/message.es6
+++ b/packages/client-app/src/flux/models/message.es6
@@ -168,10 +168,6 @@ export default class Message extends ModelWithMetadata {
       itemClass: Folder,
     }),
 
-    folderUID: Attributes.Number({
-      modelKey: 'folderUID',
-    }),
-
   });
 
   static naturalSortOrder() {
diff --git a/packages/client-app/src/flux/models/model.es6 b/packages/client-app/src/flux/models/model.es6
index 8d1dd28fc..4a35f0b93 100644
--- a/packages/client-app/src/flux/models/model.es6
+++ b/packages/client-app/src/flux/models/model.es6
@@ -40,7 +40,7 @@ export default class Model {
         this.fromJSON(data);
       } else {
         for (const key of Object.keys(this.constructor.attributes)) {
-          if (data[key]) {
+          if (data[key] !== undefined) {
             this[key] = data[key];
           }
         }
@@ -61,7 +61,7 @@ export default class Model {
   fromJSON(json) {
     for (const key of Object.keys(this.constructor.attributes)) {
       const attr = this.constructor.attributes[key];
-      const attrValue = json[attr.jsonKey];
+      const attrValue = json[attr.jsonKey || key];
       if (attrValue !== undefined) {
         this[key] = attr.fromJSON(attrValue);
       }
@@ -82,7 +82,7 @@ export default class Model {
       if (attrValue === undefined) {
         continue;
       }
-      json[attr.jsonKey] = attr.toJSON(attrValue);
+      json[attr.jsonKey || key] = attr.toJSON(attrValue);
     }
     json.__cls = this.constructor.name
     return json;
diff --git a/packages/client-app/src/flux/stores/draft-factory.coffee b/packages/client-app/src/flux/stores/draft-factory.coffee
index 61dbdcadf..1f392f280 100644
--- a/packages/client-app/src/flux/stores/draft-factory.coffee
+++ b/packages/client-app/src/flux/stores/draft-factory.coffee
@@ -30,7 +30,6 @@ class DraftFactory
       version: 0
       unread: false
       starred: false
-      folderUID: 0
       headerMessageId: Utils.generateTempId() + "@" + require('os').hostname()
       from: [account.defaultMe()]
       date: (new Date)
diff --git a/packages/client-app/src/flux/tasks/change-folder-task.es6 b/packages/client-app/src/flux/tasks/change-folder-task.es6
index 304c650e4..c7db98040 100644
--- a/packages/client-app/src/flux/tasks/change-folder-task.es6
+++ b/packages/client-app/src/flux/tasks/change-folder-task.es6
@@ -1,5 +1,6 @@
-import Category from '../models/category';
 import ChangeMailTask from './change-mail-task';
+import Attributes from '../attributes';
+import Folder from '../models/folder';
 
 // Public: Create a new task to apply labels to a message or thread.
 //
@@ -14,11 +15,15 @@ import ChangeMailTask from './change-mail-task';
 //
 export default class ChangeFolderTask extends ChangeMailTask {
 
-  constructor(options = {}) {
-    super(options);
-    this.source = options.source
-    this.taskDescription = options.taskDescription;
-    this.folder = options.folder;
+  static attributes = Object.assign({}, ChangeMailTask.attributes, {
+    folder: Attributes.Object({
+      modelKey: 'folder',
+      ItemClass: Folder,
+    }),
+  });
+
+  constructor(data = {}) {
+    super(data);
   }
 
   label() {
@@ -33,10 +38,7 @@ export default class ChangeFolderTask extends ChangeMailTask {
       return this.taskDescription;
     }
 
-    let folderText = " to folder";
-    if (this.folder instanceof Category) {
-      folderText = ` to ${this.folder.displayName}`;
-    }
+    const folderText = ` to ${this.folder.displayName}`;
 
     if (this.threadIds.length > 1) {
       return `Moved ${this.threadIds.length} threads${folderText}`;
diff --git a/packages/client-app/src/flux/tasks/change-labels-task.es6 b/packages/client-app/src/flux/tasks/change-labels-task.es6
index f476b4d30..4afe016bc 100644
--- a/packages/client-app/src/flux/tasks/change-labels-task.es6
+++ b/packages/client-app/src/flux/tasks/change-labels-task.es6
@@ -1,6 +1,6 @@
 import Label from '../models/label';
-import Category from '../models/category';
 import ChangeMailTask from './change-mail-task';
+import Attributes from '../attributes';
 
 // Public: Create a new task to apply labels to a message or thread.
 //
@@ -9,14 +9,22 @@ import ChangeMailTask from './change-mail-task';
 // - labelsToRemove: An {Array} of {Category}s or {Category} ids to remove
 // - threads: An {Array} of {Thread}s or {Thread} ids
 // - messages: An {Array} of {Message}s or {Message} ids
+//
 export default class ChangeLabelsTask extends ChangeMailTask {
 
+  static attributes = Object.assign({}, ChangeMailTask.attributes, {
+    labelsToAdd: Attributes.Collection({
+      modelKey: 'labelsToAdd',
+      ItemClass: Label,
+    }),
+    labelsToRemove: Attributes.Collection({
+      modelKey: 'labelsToRemove',
+      ItemClass: Label,
+    }),
+  });
+
   constructor(options = {}) {
     super(options);
-    this.source = options.source
-    this.labelsToAdd = options.labelsToAdd || [];
-    this.labelsToRemove = options.labelsToRemove || [];
-    this.taskDescription = options.taskDescription;
   }
 
   label() {
@@ -35,35 +43,29 @@ export default class ChangeLabelsTask extends ChangeMailTask {
 
     const removed = this.labelsToRemove[0];
     const added = this.labelsToAdd[0];
-    const objectsAvailable = (added || removed) instanceof Category;
 
-    // Note: In the future, we could move this logic to the task
-    // factory and pass the string in as this.taskDescription (ala Snooze), but
-    // it's nice to have them declaratively based on the actual labels.
-    if (objectsAvailable) {
-      // Spam / trash interactions are always "moves" because they're the three
-      // folders of Gmail. If another folder is involved, we need to decide to
-      // return either "Moved to Bla" or "Added Bla".
-      if (added && added.name === 'spam') {
-        return `Marked${countString} as Spam`;
-      } else if (removed && removed.name === 'spam') {
-        return `Unmarked${countString} as Spam`;
-      } else if (added && added.name === 'trash') {
-        return `Trashed${countString}`;
-      } else if (removed && removed.name === 'trash') {
-        return `Removed${countString} from Trash`;
-      }
-      if (this.labelsToAdd.length === 0 && this.labelsToRemove.find(l => l.role === 'inbox')) {
-        return `Archived${countString}`;
-      } else if (this.labelsToRemove.length === 0 && this.labelsToAdd.find(l => l.role === 'inbox')) {
-        return `Unarchived${countString}`;
-      }
-      if (this.labelsToAdd.length === 1 && this.labelsToRemove.length === 0) {
-        return `Added ${added.displayName}${countString ? ' to' : ''}${countString}`;
-      }
-      if (this.labelsToAdd.length === 0 && this.labelsToRemove.length === 1) {
-        return `Removed ${removed.displayName}${countString ? ' from' : ''}${countString}`;
-      }
+    // Spam / trash interactions are always "moves" because they're the three
+    // folders of Gmail. If another folder is involved, we need to decide to
+    // return either "Moved to Bla" or "Added Bla".
+    if (added && added.name === 'spam') {
+      return `Marked${countString} as Spam`;
+    } else if (removed && removed.name === 'spam') {
+      return `Unmarked${countString} as Spam`;
+    } else if (added && added.name === 'trash') {
+      return `Trashed${countString}`;
+    } else if (removed && removed.name === 'trash') {
+      return `Removed${countString} from Trash`;
+    }
+    if (this.labelsToAdd.length === 0 && this.labelsToRemove.find(l => l.role === 'inbox')) {
+      return `Archived${countString}`;
+    } else if (this.labelsToRemove.length === 0 && this.labelsToAdd.find(l => l.role === 'inbox')) {
+      return `Unarchived${countString}`;
+    }
+    if (this.labelsToAdd.length === 1 && this.labelsToRemove.length === 0) {
+      return `Added ${added.displayName}${countString ? ' to' : ''}${countString}`;
+    }
+    if (this.labelsToAdd.length === 0 && this.labelsToRemove.length === 1) {
+      return `Removed ${removed.displayName}${countString ? ' from' : ''}${countString}`;
     }
     return `Changed labels${countString ? ' on' : ''}${countString}`;
   }
diff --git a/packages/client-app/src/flux/tasks/change-mail-task.es6 b/packages/client-app/src/flux/tasks/change-mail-task.es6
index 5915f07ed..57462edaf 100644
--- a/packages/client-app/src/flux/tasks/change-mail-task.es6
+++ b/packages/client-app/src/flux/tasks/change-mail-task.es6
@@ -1,4 +1,5 @@
 import Task from './task';
+import Attributes from '../attributes';
 
 /*
 Public: The ChangeMailTask is a base class for all tasks that modify sets
@@ -20,8 +21,20 @@ requests. It does not call {ChangeMailTask::changesToModel}.
 */
 export default class ChangeMailTask extends Task {
 
-  constructor({threads, thread, messages, message} = {}) {
-    super();
+  static attributes = Object.assign({}, ChangeMailTask.attributes, {
+    taskDescription: Attributes.String({
+      modelKey: 'taskDescription',
+    }),
+    threadIds: Attributes.Collection({
+      modelKey: 'threadIds',
+    }),
+    messageIds: Attributes.Collection({
+      modelKey: 'messageIds',
+    }),
+  });
+
+  constructor({threads, thread, messages, message, ...rest} = {}) {
+    super(rest);
 
     const t = threads || [];
     if (thread) {
diff --git a/packages/client-app/src/flux/tasks/change-starred-task.es6 b/packages/client-app/src/flux/tasks/change-starred-task.es6
index 9fa3280b2..64305c938 100644
--- a/packages/client-app/src/flux/tasks/change-starred-task.es6
+++ b/packages/client-app/src/flux/tasks/change-starred-task.es6
@@ -1,15 +1,22 @@
 /* eslint no-unused-vars: 0*/
 import _ from 'underscore';
+import Attributes from '../attributes';
 import Thread from '../models/thread';
 import Actions from '../actions'
 import DatabaseStore from '../stores/database-store';
 import ChangeMailTask from './change-mail-task';
 
 export default class ChangeStarredTask extends ChangeMailTask {
-  constructor(options = {}) {
-    super(options);
-    this.source = options.source;
-    this.starred = options.starred;
+
+  static attributes = Object.assign({}, ChangeMailTask.attributes, {
+    starred: Attributes.Boolean({
+      modelKey: 'starred',
+    }),
+  });
+
+  constructor({starred, ...rest} = {}) {
+    super(rest);
+    this.starred = starred;
   }
 
   label() {
diff --git a/packages/client-app/src/flux/tasks/change-unread-task.es6 b/packages/client-app/src/flux/tasks/change-unread-task.es6
index 6a4c69d2d..ee9207bd5 100644
--- a/packages/client-app/src/flux/tasks/change-unread-task.es6
+++ b/packages/client-app/src/flux/tasks/change-unread-task.es6
@@ -2,15 +2,25 @@
 import _ from 'underscore';
 import Thread from '../models/thread';
 import Actions from '../actions'
+import Attributes from '../attributes';
 import DatabaseStore from '../stores/database-store';
 import ChangeMailTask from './change-mail-task';
 
 export default class ChangeUnreadTask extends ChangeMailTask {
-  constructor(options = {}) {
-    super(options);
-    this.source = options.source;
-    this.unread = options.unread;
-    this._canBeUndone = options.canBeUndone;
+
+  static attributes = Object.assign({}, ChangeMailTask.attributes, {
+    starred: Attributes.Boolean({
+      modelKey: 'unread',
+    }),
+    _canBeUndone: Attributes.Boolean({
+      modelKey: '_canBeUndone',
+    }),
+  });
+
+  constructor({unread, canBeUndone, ...rest} = {}) {
+    super(rest);
+    this.unread = unread;
+    this._canBeUndone = canBeUndone;
   }
 
   label() {
diff --git a/packages/client-app/src/flux/tasks/destroy-category-task.es6 b/packages/client-app/src/flux/tasks/destroy-category-task.es6
index 7665fe3e2..848713dd5 100644
--- a/packages/client-app/src/flux/tasks/destroy-category-task.es6
+++ b/packages/client-app/src/flux/tasks/destroy-category-task.es6
@@ -1,12 +1,13 @@
 import Task from './task';
+import Attributes from '../attributes';
 
 export default class DestroyCategoryTask extends Task {
 
-  constructor({path, accountId} = {}) {
-    super();
-    this.path = path;
-    this.accountId = accountId;
-  }
+  static attributes = Object.assign({}, Task.attributes, {
+    path: Attributes.String({
+      modelKey: 'path',
+    }),
+  });
 
   label() {
     return `Deleting ${this.category.displayType()} ${this.category.displayName}`
diff --git a/packages/client-app/src/flux/tasks/destroy-draft-task.es6 b/packages/client-app/src/flux/tasks/destroy-draft-task.es6
index b596f67b6..24543c79a 100644
--- a/packages/client-app/src/flux/tasks/destroy-draft-task.es6
+++ b/packages/client-app/src/flux/tasks/destroy-draft-task.es6
@@ -1,9 +1,11 @@
 import Task from './task';
+import Attributes from '../attributes';
 
 export default class DestroyDraftTask extends Task {
-  constructor(accountId, headerMessageId) {
-    super();
-    this.accountId = accountId;
-    this.headerMessageId = headerMessageId;
-  }
+
+  static attributes = Object.assign({}, Task.attributes, {
+    headerMessageId: Attributes.String({
+      modelKey: 'headerMessageId',
+    }),
+  });
 }
diff --git a/packages/client-app/src/flux/tasks/send-draft-task.es6 b/packages/client-app/src/flux/tasks/send-draft-task.es6
index 6b5aff8a8..edeaf1c54 100644
--- a/packages/client-app/src/flux/tasks/send-draft-task.es6
+++ b/packages/client-app/src/flux/tasks/send-draft-task.es6
@@ -3,6 +3,8 @@ import AccountStore from '../stores/account-store';
 import Task from './task';
 import Actions from '../actions';
 import SoundRegistry from '../../registries/sound-registry';
+import Attributes from '../attributes';
+import Message from '../models/message';
 
 const OPEN_TRACKING_ID = NylasEnv.packages.pluginIdFor('open-tracking')
 const LINK_TRACKING_ID = NylasEnv.packages.pluginIdFor('link-tracking')
@@ -10,12 +12,32 @@ const LINK_TRACKING_ID = NylasEnv.packages.pluginIdFor('link-tracking')
 
 export default class SendDraftTask extends Task {
 
-  constructor(draft, {playSound = true, emitError = true, allowMultiSend = true} = {}) {
-    super();
-    this.draft = draft;
+  static attributes = Object.assign({}, Task.attributes, {
+    draft: Attributes.Object({
+      modelKey: 'draft',
+      itemClass: Message,
+    }),
+    headerMessageId: Attributes.String({
+      modelKey: 'headerMessageId',
+    }),
+    emitError: Attributes.Boolean({
+      modelKey: 'emitError',
+    }),
+    playSound: Attributes.Boolean({
+      modelKey: 'playSound',
+    }),
+    allowMultiSend: Attributes.Boolean({
+      modelKey: 'allowMultiSend',
+    }),
+    perRecipientBodies: Attributes.Collection({
+      modelKey: 'perRecipientBodies',
+    }),
+  });
+
+  constructor({draft, playSound = true, emitError = true, allowMultiSend = true, ...rest} = {}) {
+    super(rest);
     this.accountId = (draft || {}).accountId;
     this.headerMessageId = (draft || {}).headerMessageId;
-
     this.emitError = emitError
     this.playSound = playSound
     this.allowMultiSend = allowMultiSend
diff --git a/packages/client-app/src/flux/tasks/syncback-category-task.es6 b/packages/client-app/src/flux/tasks/syncback-category-task.es6
index 235c4a31d..90f1c1188 100644
--- a/packages/client-app/src/flux/tasks/syncback-category-task.es6
+++ b/packages/client-app/src/flux/tasks/syncback-category-task.es6
@@ -1,13 +1,25 @@
 import Task from './task';
+import Attributes from '../attributes';
 
 export default class SyncbackCategoryTask extends Task {
 
-  constructor({existingPath, path, accountId} = {}) {
-    super()
+  static attributes = Object.assign({}, Task.attributes, {
+    path: Attributes.String({
+      modelKey: 'path',
+    }),
+    existingPath: Attributes.String({
+      modelKey: 'existingPath',
+    }),
+    created: Attributes.Object({
+      modelKey: 'created',
+    }),
+  });
+
+  constructor({existingPath, path, accountId, ...rest} = {}) {
+    super(rest);
     this.existingPath = existingPath;
     this.path = path;
     this.accountId = accountId;
-    this.created = null;
   }
 
   label() {
diff --git a/packages/client-app/src/flux/tasks/syncback-draft-task.es6 b/packages/client-app/src/flux/tasks/syncback-draft-task.es6
index 8ef2b460a..747e4f7fb 100644
--- a/packages/client-app/src/flux/tasks/syncback-draft-task.es6
+++ b/packages/client-app/src/flux/tasks/syncback-draft-task.es6
@@ -1,8 +1,21 @@
 import Task from './task';
+import Attributes from '../attributes';
+import Message from '../models/message';
 
 export default class SyncbackDraftTask extends Task {
-  constructor(draft) {
-    super();
+
+  static attributes = Object.assign({}, Task.attributes, {
+    headerMessageId: Attributes.String({
+      modelKey: 'headerMessageId',
+    }),
+    draft: Attributes.Object({
+      modelKey: 'draft',
+      itemClass: Message,
+    }),
+  });
+
+  constructor({draft, ...rest} = {}) {
+    super(rest);
     this.draft = draft;
     this.accountId = (draft || {}).accountId;
     this.headerMessageId = (draft || {}).headerMessageId;
diff --git a/packages/client-app/src/flux/tasks/syncback-metadata-task.es6 b/packages/client-app/src/flux/tasks/syncback-metadata-task.es6
index 01c6c871c..8e62b04e0 100644
--- a/packages/client-app/src/flux/tasks/syncback-metadata-task.es6
+++ b/packages/client-app/src/flux/tasks/syncback-metadata-task.es6
@@ -15,14 +15,6 @@ export default class SyncbackMetadataTask extends SyncbackModelTask {
     return DatabaseObjectRegistry.get(this.modelClassName);
   }
 
-  isDependentOnTask(otherTask) {
-    return (
-      otherTask instanceof SyncbackMetadataTask &&
-      otherTask.pluginId === this.pluginId &&
-      otherTask.sequentialId < this.sequentialId
-    )
-  }
-
   makeRequest = async (model) => {
     if (!model.serverId) {
       throw new Error(`Can't syncback metadata for a ${this.modelClassName} instance that doesn't have a serverId`)
diff --git a/packages/client-app/src/flux/tasks/task.es6 b/packages/client-app/src/flux/tasks/task.es6
index f334c8cd1..647db478a 100644
--- a/packages/client-app/src/flux/tasks/task.es6
+++ b/packages/client-app/src/flux/tasks/task.es6
@@ -27,6 +27,9 @@ export default class Task extends Model {
       queryable: true,
       modelKey: 'status',
     }),
+    source: Attributes.String({
+      modelKey: 'source',
+    }),
     error: Attributes.Object({
       modelKey: 'error',
     }),
@@ -39,13 +42,10 @@ export default class Task extends Model {
   // `super`.
   //
   // On construction, all Tasks instances are given a unique `id`.
-  constructor() {
-    super();
-    this.version = 1;
-    this._rememberedToCallSuper = true;
-    this.id = generateTempId();
+  constructor(data) {
+    super(data);
+    this.id = this.id || generateTempId();
     this.accountId = null;
-    this.sequentialId = null; // set when queued
   }
 
   // Public: Override to raise exceptions if your task is missing required