How to set email recipients when creating Gmail drafts via API

Other Questions Gmail
1

I’m working with the Gmail API using Ruby and I can successfully create draft messages. However, I’m having trouble adding recipients to these drafts. The draft gets created fine but no recipients are included.

I looked at existing drafts through the Google API explorer and tried to copy their structure. Here’s what I’m attempting:

response = gmail_client.execute(
  :api_method => gmail_service.users.drafts.create,
  :parameters => {
    'userId' => "me"
  },
  :body_object => {
    'message' => {
      'raw' => Base64.urlsafe_encode64('Sample draft content'),
      'payload' => {
        'headers' => [
          {
            'name' => "To",
            'value' => "Jane Doe <[email protected]>"
          }
        ]
      }
    }
  }
)

The draft appears in Gmail but without any recipients set. What’s the correct way to include recipient information when creating drafts through the Gmail API?

2

You’re mixing raw and structured message formats, which won’t work. When you use the raw parameter, you need the entire RFC 2822 formatted message as a string with headers included. You can’t use both raw and payload together.

Here’s how to build the full message string:

message_content = [
  "To: [email protected]",
  "Subject: Your Subject Here",
  "",
  "Sample draft content"
].join("\r\n")

response = gmail_client.execute(
  :api_method => gmail_service.users.drafts.create,
  :parameters => {
    'userId' => "me"
  },
  :body_object => {
    'message' => {
      'raw' => Base64.urlsafe_encode64(message_content)
    }
  }
)

Or just ditch the raw parameter and stick with the payload structure using proper headers. I’ve had better luck with the raw approach for drafts that need recipients.

3

yeah, this is a common gmail api gotcha. you’re mixing raw + payload like others mentioned. i just stick with the raw approach since it’s simpler - just don’t forget the proper line breaks (\r\n) between headers and body or gmail can’t parse it right.

4

You can’t mix raw and payload parameters in the same request. When you use raw, Gmail requires a complete RFC 2822 message string that includes all headers in-line, rather than using separate payload objects. I faced a similar issue previously and found two solutions that work. The first option is to build your entire message as a string before encoding it. The second option is to discard the raw parameter and only utilize the payload structure. While the payload approach needs a proper setup for message parts, it allows for greater control over complex messages. Both methods work effectively as long as the formats are not mixed.