Project BlueSends the line's saved name and photo into an existing 1:1 conversation, so Messages on the recipient's side offers to update the contact. Apple decides when the recipient sees it; it usually appears with the next message in that thread.
POST/share-contact-cardBearer token
Request body
lineIdstring (UUID v4)RequiredThe line whose card to share. The line must already have a card from POST /set-contact-card.
destinationstringRequiredThe recipient — a phone number (any common format, normalised to E.164) or an iMessage email address. An iMessage conversation between the line and this destination must already exist; send a message first if it does not.
The conversation must already exist
Sharing goes into a chat, not to a number. If the line has never exchanged a message with the destination you get
404 CHAT_NOT_FOUND. Send one message with /send-api-message first, then share.SHARED means the line accepted it
confirmation: LINE_ACCEPTED is exactly that — Messages on the line took the send. The API cannot see whether the recipient's device displayed the card, so there is no “delivered” state and none is implied.Status codes
- 200
- SHARED — the line accepted the send.
- 400
- Bad lineId or destination.
- 401
- Missing or invalid API key.
- 403
- Trial account, or
LINE_NOT_ELIGIBLE. - 404
CHAT_NOT_FOUND— no conversation with the destination on this line.- 409
NO_CONTACT_CARD— set one first; or the line is not ready (same codes as set).- 429
- Rate limit exceeded.
- 502
SHARE_REJECTED— the line refused the share.- 503
LINE_OFFLINE— nothing was shared; retry shortly.- 504
SHARE_TIMEOUT— INDETERMINATE; the card may have gone out.
Idempotency and resharing
The same line, destination and card revision within a short window is one share; a repeat replays the first result with
deduped: true. Updating the card changes its revision, so share-after-update always sends. An INDETERMINATE result is cached, so a blind retry after a timeout does not send a second card — pass a new Idempotency-Key once the recipient confirms nothing arrived.