Appendix C: Client extension HTTP Request Headers

The gateway can send additional envelope data to the HTTP-based client endpoint using extension HTTP headers if the client bind configuration permits it. All headers are prefixed with X-Lark-. The list of headers that can be sent is as below:

  • X-Lark-Carrier-Message-ID: The message ID received from the supplier side on MT transmission.
  • X-Lark-Mmsc-ID: The bind ID of the sender supplier bind
  • X-Lark-Mmsc-GroupID: The bind group ID
  • X-Lark-UAProf: The device user agent identifier (officially the WAP User Agent Profile string), usually sent as part of the retrieval notification DLR.
  • X-Lark-Timestamp: This is the DLR timestamp sent by the supplier.
  • X-Lark-TransactionID: The supplier-side transaction ID
  • X-Lark-Timestamp-M-Received: The timestamp (in microseconds) when the DLR was received from the supplier bind. 
  • X-Lark-Timestamp-A-Received: The timestamp (in microseconds) when the original message was received by the gateway.
  • X-Lark-Timestamp-ACK-Received: The timestamp (in microseconds) when the gateway successfully sent the message to the supplier (and the supplier acknowledged it in the protocol transaction response). 
  • X-Lark-StatusText: The status text in the DLR
  • X-Lark-StatusCode: The status code returned by the supplier during MT transmission. For MM7 this is the StatusCode XML content.
  • X-Lark-Http-Status-Code: The HTTP status code returned by the supplier during MT transmission. This is for HTTP-based protocols only.
  • X-Lark-StatusDetails: The extra status information in the DLR packet (typically sent by MM7 suppliers).
  • X-Lark-Orig-Message-ID: The original message ID as provided to the client when the MT was submitted. This is usually sent in the DLR.
  • X-Lark-Allow-Adaptations: Set to yes or no. This is used by the client to control whether the MM1 supplier bind performs content adaptation on an MT or not. It is also passed through for MM7 binds as the AllowAdaptations MM7 tag.
  • X-Lark-Error: If MT submission resulted in an error message (e.g. MM7 error), the error will be returned to the client using this header.
  • X-Lark-SendSMS-MetaData: This is used by the client to specify SMPP metadata (also known as custom TLVs) to be sent with the MM1 notification.
  • X-Lark-SMSC-Message-ID: This is the SMSC message ID returned when the MM1 notification is sent to the supplier SMS gateway (e.g. SMPP MC).