Spruce Messages API
Post messages into a conversation, list and retrieve conversation items (messages, calls, faxes, secure conversation events), delete a conversation item, upload media for attachment, send messages from an internal endpoint or phone line, create proxy calls, and schedule / list / delete scheduled and saved messages.
Documentation
Documentation
https://developer.sprucehealth.com/docs/overview
APIReference
https://developer.sprucehealth.com/reference/postconversationmessage