feat: inline attachment support

Author: drish

examples/with_inline_attachments.py

@@ -0,0 +1,33 @@
+import os
+
+import resend
+
+if not os.environ["RESEND_API_KEY"]:
+    raise EnvironmentError("RESEND_API_KEY is missing")
+
+f: bytes = open(
+    os.path.join(os.path.dirname(__file__), "../resources/resend-wordmark-black.png"),
+    "rb",
+).read()
+
+# Define the file attachment
+attachment: resend.Attachment = {
+    "filename": "resend-wordmark-black.png",
+    "content": list(f),
+    "content_type": "image/png",
+    # This is the content ID that will be used in the HTML to reference the image
+    "inline_content_id": "my-test-image",
+}
+
+# Define the email parameters
+params: resend.Emails.SendParams = {
+    "from": "onboarding@resend.dev",
+    "to": ["delivered@resend.dev"],
+    "subject": "Inline attachment test from Resend's python SDK",
+    "html": '<p>This is an email with an <img width=100 height=40 src="cid:my-test-image" /> embed image</p>',
+    "attachments": [attachment],
+}
+
+email: resend.Email = resend.Emails.send(params)
+print("Sent email with attachment")
+print(email)

resend/emails/_attachment.py

@@ -23,3 +23,7 @@ class Attachment(TypedDict):
     """
     Content type for the attachment, if not set will be derived from the filename property
     """
+    inline_content_id: NotRequired[str]
+    """
+    Content ID for inline attachments used in HTML content with cid: references
+    """

resources/resend-wordmark-black.png

@@ -109,3 +109,50 @@ def test_cancel_scheduled_email(self) -> None:
             email_id="49a3999c-0ce1-4ea6-ab68-afcd6dc2e794"
         )
         assert email["id"] == "49a3999c-0ce1-4ea6-ab68-afcd6dc2e794"
+
+    def test_email_send_with_attachment(self) -> None:
+        self.set_mock_json(
+            {
+                "id": "49a3999c-0ce1-4ea6-ab68-afcd6dc2e794",
+            }
+        )
+
+        attachment: resend.Attachment = {
+            "filename": "test.pdf",
+            "content": [1, 2, 3, 4, 5],
+            "content_type": "application/pdf",
+        }
+
+        params: resend.Emails.SendParams = {
+            "to": "to@email.com",
+            "from": "from@email.com",
+            "subject": "subject",
+            "html": "html",
+            "attachments": [attachment],
+        }
+        email: resend.Email = resend.Emails.send(params)
+        assert email["id"] == "49a3999c-0ce1-4ea6-ab68-afcd6dc2e794"
+
+    def test_email_send_with_inline_attachment(self) -> None:
+        self.set_mock_json(
+            {
+                "id": "49a3999c-0ce1-4ea6-ab68-afcd6dc2e794",
+            }
+        )
+
+        attachment: resend.Attachment = {
+            "filename": "image.png",
+            "content": [1, 2, 3, 4, 5],
+            "content_type": "image/png",
+            "inline_content_id": "my-image",
+        }
+
+        params: resend.Emails.SendParams = {
+            "to": "to@email.com",
+            "from": "from@email.com",
+            "subject": "subject",
+            "html": '<img src="cid:my-image" />',
+            "attachments": [attachment],
+        }
+        email: resend.Email = resend.Emails.send(params)
+        assert email["id"] == "49a3999c-0ce1-4ea6-ab68-afcd6dc2e794"