diff --git a/CHANGELOG.md b/CHANGELOG.md
index e19006b9..ebef259b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Changelog
 
+### Unreleased
+* Add support for adding custom headers to outgoing requests
+* Add support for custom headers field for drafts and messages
+* Rename incorrect `type` field in `When` models to `object`
+
 ### 7.2.1 / 2024-03-05
 * Improved message sending and draft create/update performance
 * Change default timeout to match API (90 seconds)
diff --git a/src/models/drafts.ts b/src/models/drafts.ts
index 3e6ce47e..b2f38f12 100644
--- a/src/models/drafts.ts
+++ b/src/models/drafts.ts
@@ -3,6 +3,17 @@ import { ListQueryParams } from './listQueryParams.js';
 import { EmailName } from './events.js';
 import { CreateAttachmentRequest } from './attachments.js';
 
+export interface CustomHeader {
+  /**
+   * The name of the custom header.
+   */
+  name: string;
+  /**
+   * The value of the custom header.
+   */
+  value: string;
+}
+
 /**
  * Interface representing a request to create a draft.
  */
@@ -56,6 +67,10 @@ export interface CreateDraftRequest {
    * Options for tracking opens, links, and thread replies.
    */
   trackingOptions?: TrackingOptions;
+  /**
+   * An array of custom headers to add to the message.
+   */
+  customHeaders?: CustomHeader[];
 }
 
 /**
diff --git a/tests/resources/drafts.spec.ts b/tests/resources/drafts.spec.ts
index 4456a50a..8ce6a6e5 100644
--- a/tests/resources/drafts.spec.ts
+++ b/tests/resources/drafts.spec.ts
@@ -2,6 +2,7 @@ import APIClient from '../../src/apiClient';
 import { Drafts } from '../../src/resources/drafts';
 import { createReadableStream, MockedFormData } from '../testUtils';
 import { CreateAttachmentRequest } from '../../src/models/attachments';
+import { objKeysToCamelCase } from '../../src/utils';
 jest.mock('../src/apiClient');
 
 // Mock the FormData constructor
@@ -33,6 +34,100 @@ describe('Drafts', () => {
     apiClient.request.mockResolvedValue({});
   });
 
+  describe('deserializing', () => {
+    it('should return a draft object as expected', () => {
+      const apiDraft = {
+        body: 'Hello, I just sent a message using Nylas!',
+        cc: [
+          {
+            email: 'arya.stark@example.com',
+          },
+        ],
+        attachments: [
+          {
+            content_type: 'text/calendar',
+            id: '4kj2jrcoj9ve5j9yxqz5cuv98',
+            size: 1708,
+          },
+        ],
+        folders: ['8l6c4d11y1p4dm4fxj52whyr9', 'd9zkcr2tljpu3m4qpj7l2hbr0'],
+        from: [
+          {
+            name: 'Daenerys Targaryen',
+            email: 'daenerys.t@example.com',
+          },
+        ],
+        grant_id: '41009df5-bf11-4c97-aa18-b285b5f2e386',
+        id: '5d3qmne77v32r8l4phyuksl2x',
+        object: 'draft',
+        reply_to: [
+          {
+            name: 'Daenerys Targaryen',
+            email: 'daenerys.t@example.com',
+          },
+        ],
+        snippet: 'Hello, I just sent a message using Nylas!',
+        starred: true,
+        subject: 'Hello from Nylas!',
+        thread_id: '1t8tv3890q4vgmwq6pmdwm8qgsaer',
+        to: [
+          {
+            name: 'Jon Snow',
+            email: 'j.snow@example.com',
+          },
+        ],
+        date: 1705084742,
+        created_at: 1705084926,
+      };
+
+      const draft = objKeysToCamelCase(apiDraft);
+
+      expect(draft).toEqual({
+        body: 'Hello, I just sent a message using Nylas!',
+        cc: [
+          {
+            email: 'arya.stark@example.com',
+          },
+        ],
+        attachments: [
+          {
+            contentType: 'text/calendar',
+            id: '4kj2jrcoj9ve5j9yxqz5cuv98',
+            size: 1708,
+          },
+        ],
+        folders: ['8l6c4d11y1p4dm4fxj52whyr9', 'd9zkcr2tljpu3m4qpj7l2hbr0'],
+        from: [
+          {
+            name: 'Daenerys Targaryen',
+            email: 'daenerys.t@example.com',
+          },
+        ],
+        grantId: '41009df5-bf11-4c97-aa18-b285b5f2e386',
+        id: '5d3qmne77v32r8l4phyuksl2x',
+        object: 'draft',
+        replyTo: [
+          {
+            name: 'Daenerys Targaryen',
+            email: 'daenerys.t@example.com',
+          },
+        ],
+        snippet: 'Hello, I just sent a message using Nylas!',
+        starred: true,
+        subject: 'Hello from Nylas!',
+        threadId: '1t8tv3890q4vgmwq6pmdwm8qgsaer',
+        to: [
+          {
+            name: 'Jon Snow',
+            email: 'j.snow@example.com',
+          },
+        ],
+        date: 1705084742,
+        createdAt: 1705084926,
+      });
+    });
+  });
+
   describe('list', () => {
     it('should call apiClient.request with the correct params', async () => {
       await drafts.list({