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Get started
From Maven Central to your first bound session in five minutes.
Free & open source · SMPP 3.4 · Java 21
SMS infrastructure for modern Java.
smpp-core is the fastest open-source SMPP library on the JVM - Java 21 virtual threads, zero-copy Netty codecs, windowing and reconnect built in. Free under Apache-2.0, and the actively maintained successor to Cloudhopper.
SmppClient client = SmppClient.builder() .host("smsc.carrier.net").port(2775) .systemId("esme").password("secret") .bindType(SmppBindType.TRANSCEIVER) .build(); SmppClientSession session = client.connect(); // async submit with a CompletableFuture session.submitSm(message) .thenAccept(resp -> log.info(resp.messageId()));
SmppServer server = SmppServer.builder() .port(2775) .systemId("smsc") .maxConnections(100) .handler(new MyServerHandler()) .build(); server.start(); // virtual threads: every session gets its own, // thousands of sessions, zero pool tuning
<!-- one dependency, on Maven Central --> <dependency> <groupId>io.smppgateway</groupId> <artifactId>smpp-core</artifactId> <version>1.0.9</version> </dependency>
1.5M+PDUs encoded per second
25,000messages/s over real TCP - 25× a tuned Cloudhopper
~1 KBmemory per session (virtual threads)
Free, foreverApache-2.0 - no paid tiers, no license keys
Start building
Everything ships documented - pick your entry point.
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smpp-core
Client, server, PDUs and codecs - the full SMPP 3.4 surface.
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Kafka bridge
SMPP in, events out - a hardened, containerized producer service.
Built for production traffic
The reliability machinery lives in the library, not in your code.
Virtual threads
Thousands of concurrent sessions on Java 21 - around 1 KB each, no thread-pool tuning, ever.
Zero-copy codecs
PDUs encode directly into Netty buffers. Nothing is copied on the hot path.
Immutable PDUs
Records and sealed types make every message thread-safe by construction.
Windowing & reconnect
Request windows, automatic reconnect, and TLS handled for you - your code only sees acknowledged messages.
Metrics built in
Prometheus and Grafana wiring via Micrometer, one optional dependency away.
Kafka bridge
A production SMPP-to-Kafka service with an HTTP/2 API - Docker and Kubernetes ready.
Two projects, one stack
Use the library alone, or deploy the bridge alongside it.
smpp-core library
The core SMPP 3.4 implementation - PDUs, codecs, server and client. Everything above rides on it.
smpp-kafka-producer service
A production SMPP-to-Kafka bridge with an HTTP/2 REST API, Docker images, and Kubernetes manifests.
Bind your first session in five minutes.
Free and open source under Apache-2.0 - add smpp-core from Maven Central and start moving messages.
Need setup help, tuning, or custom SMPP development? Talk to us.