gmail.updateDraft changes content, recipients, or attachments without sending the draft or moving it to another thread.
Example
automations/update-approved-draft.automation.ts
Inputs
Recipient is an email string or { address: string; name?: string }. Attachment is a File or an object containing file with optional filename, contentId, and disposition: "attachment" | "inline".
Inputs accept compatible signals.
Supplying either html or text replaces both body alternatives. If you supply only html, Automate.ax derives replacement plain text. Supplying attachments replaces the complete attachment list. Use [] to remove all attachments.
Omitted recipients, sender, reply addresses, subject, body, and attachments
are preserved. Custom headers and priority are applied only when supplied;
existing arbitrary headers and priority are not copied forward.
Output
ReturnsSignal<DraftIdentifier>: