Overview

The SMPP connector provides native Ballerina access to an SMSC (Short Message Service Centre) over SMPP (Short Message Peer-to-Peer), the protocol an ESME (External Short Messaging Entity) uses to exchange SMS traffic with a carrier or aggregator. It wraps the Java library org.jsmpp:jsmpp through Ballerina's Java interoperability.

Key features

• Send text or pre-encoded binary messages (submit_sm), to a single destination or to several at once (submit_multi)
• Send via the alternative data_sm transfer PDU for binary/WAP-push payloads
• Query, cancel, and replace a previously submitted, not-yet-delivered message (query_sm, cancel_sm, replace_sm)
• Receive mobile-originated messages and delivery receipts (deliver_sm/data_sm) via a listener and service model
• Reply on the same session a message was received on, through a Caller injected into a transceiver-bound service
• TLS for both the client and the listener, including mutual TLS
• A single typed error carrying a failure mode so retry logic can branch on why an operation failed, and whether a retry can duplicate the message

Actions

The connector provides a single client for outbound communication with an SMSC.

Client	Actions
Client	submit_sm, submit_multi, data_sm, query_sm, cancel_sm, replace_sm, connection lifecycle

See the Action Reference for the full list of operations, parameters, and sample code for each client.

Triggers

The connector supports event-driven integration by binding to the SMSC as a receiver or transceiver, enabling the SMSC to push mobile-originated messages and delivery receipts to the Ballerina service.

Supported trigger events:

Event	Callback	Description
Message received	onDeliverSm	Invoked when a deliver_sm PDU arrives: a mobile-originated message or a delivery receipt
Data message received	onDataSm	Invoked when a data_sm PDU arrives, the alternative inbound transfer PDU some SMSCs use
Framework error	onError	Invoked when an unexpected session drop occurs

See the Trigger Reference for listener configuration, service callbacks, and the event payload structure.

Documentation

• Setup Guide: This guide walks you through obtaining SMPP access from an SMSC, carrier, or aggregator and collecting the connection details the connector needs.

• Action Reference: Full reference for the Client: operations, parameters, return types, and sample code.

• Trigger Reference: Reference for event-driven integration using the Listener, Service, and Caller model.

• Example: Learn how to build and configure an integration using the SMPP connector, including connection setup, operation configuration, and execution flow.

How to contribute

As an open source project, WSO2 welcomes contributions from the community.

To contribute to the code for this connector, please create a pull request in the following repository.

• SMPP Connector GitHub repository

Check the issue tracker for open issues that interest you. We look forward to receiving your contributions.