Threads

Threads group related messages into conversations. List threads for a mailbox, view messages in a thread, or reply to an existing thread.

List threads

GET /v1/threads?mailbox_id=mbx_abc123

Scope: threads:read. Rate limit tier: read.

The mailbox_id query parameter is required. Supports cursor and limit pagination parameters.

Returns a paginated list of messages grouped by thread.

GET /v1/threads/:id

Scope: threads:read. Returns a paginated list of messages in the thread. Supports cursor and limit parameters.

POST /v1/threads/:id/reply

Scope: messages:write. Rate limit tier: send. Sends a reply using the same mailbox as the latest message in the thread.

Field	Type	Required	Description
html	string	*	HTML body. Max 512 KB.
text	string	*	Plain text body. Max 256 KB.
to	recipient[]	Yes	To recipients. At least one required.
cc	recipient[]	No	CC recipients.

* At least one of html or text is required. Total recipients (to + cc) must not exceed 50.

Returns the message object with status 201.