One minimalist API, 12 transports, zero-cost switching

Official website: https://vlink.work

Github: https://github.com/thun-res/vlink

English | 中文

VLink is a lightweight C++ communication middleware for autonomous driving and embodied intelligence, positioned as a minimalist alternative to ROS 2.

A minimalist API (3–5 lines to get communication going), zero-cost transport switching, and compile-time serialization deduction. Ships with 12 transports, 14 serialization formats, 3 communication models, 9 CLI tools, and optional Foxglove / Rerun visualization bridges.

📚 Documentation

Part I — Getting Started

Documentation	Content
Whitepaper	Background, positioning, architecture & technical deep-dive
Build Guide	CMake / Conan / Integration / Cross-platform
Examples	Runnable samples (fastest on-ramp)

Part II — Core Communication Models

Documentation	Content
Event Model	Publisher / Subscriber
Method Model	Client / Server
Field Model	Setter / Getter
Serialization	14 serialization types & auto-deduction

Part III — Transport & Common Features

Documentation	Content
Transport Backends	12 backends & URL format
QoS	Quality of Service configuration
Zero-Copy	CameraFrame / PointCloud (large-payload essentials)
Base Library	Logger / MessageLoop / Timer / ThreadPool / Concurrency / IPC / Profiler
Bag Recording	Bag / MCAP file format & API
CLI Tools	9 command-line tools reference
Environment Variables	VLINK_* configuration reference

Part IV — Tools & Visualization

Documentation	Content
Viewer	Qt desktop: Viewer / Player / Analyzer
WebViz	vlink-foxglove / vlink-rerun bridges
Proxy	ProxyServer / ProxyAPI
Discovery	UDP multicast discovery & topology

Part V — Advanced Topics

Documentation	Content
Node Base	Node base template shared interface & lifecycle (init/deinit/interrupt)
Security	AES-128-CBC & custom encryption callbacks

Part VI — Extension & Contribution

Documentation	Content
C API	C wrapper & multi-language FFI (six primitives, data plane)
Extensions	Plugin system & custom transports
Testing	doctest framework & gcov/lcov
PR Conventions	Branches, commits, code style, CI gates

Quick Reference

Documentation	Content
Cheatsheet	Single-page API / URL / QoS / CLI / env-var reference
Troubleshooting	Symptom-indexed problem solving
CHANGELOG	Release notes

🚀 30-Second Tour

Quick Start

Publisher<Imu> pub("dds://sensor/imu");              // Cross-machine DDS
Publisher<Imu> pub("shm://sensor/imu");              // Same-host shared memory
Publisher<Imu> pub("intra://sensor/imu");            // In-process
 
Publisher<Imu> pub("dds://sensor/lidar?qos=sensor"); // QoS profile
Publisher<Imu> pub("shm://sensor/image?depth=10");   // History depth

URL syntax: Transport Backends.

🏛️ Architecture

VLink Architecture

🚌 Transport Backends

Scheme	Underlying	Scope	Zero-copy	Status
intra://	Lock-free queue	In-process	✅	✅ Stable
shm://	Iceoryx	Same-host IPC	✅	✅ Stable
dds://	Fast-DDS	Cross-machine	—	✅ Stable
ddsc://	CycloneDDS	Cross-machine	—	✅ Stable
shm2://	Iceoryx2	Same-host	✅	🟡 Beta
ddsr://	RTI Connext	Cross-machine	—	🟡 Beta
ddst://	TravoDDS (domestic DDS)	Cross-machine	—	🟡 Beta
zenoh://	Zenoh	Cross-machine / cloud-edge	—	🟡 Beta
someip://	vsomeip	Automotive Ethernet	—	🟡 Beta
mqtt://	Paho MQTT	Cloud	—	🟡 Beta
fdbus://	FDBus	Same-host	—	🟡 Beta
qnx://	QNX IPC	Same-host (QNX)	—	🟡 Beta

📡 Communication Models

Three Communication Models

Event — Publish/Subscribe

Publisher<Imu> publisher("dds://sensor/imu");
publisher.publish(msg);
 
Subscriber<Imu> subscriber("dds://sensor/imu");
subscriber.listen([](const Imu& msg) { process(msg); });

Method — Request/Response

Server<Req, Resp> server("dds://calc/add");
server.listen([](const Req& req, Resp& resp) {
  resp.set_sum(req.left() + req.right());
});
 
Client<Req, Resp> client("dds://calc/add");
if (auto r = client.invoke(req, 3s)) { use(*r); }  // Synchronous → std::optional<Resp>
client.invoke(req, [](const Resp& r) { use(r); }); // Async callback
auto future = client.async_invoke(req);            // Future
Client<Req> fire("dds://event/notify");            // RespT defaults to EmptyType
fire.send(req);                                    // Fire-and-forget (only when RespT = EmptyType)

Field — State Synchronization

Setter<Status> setter("shm://vehicle/status");
setter.set(status);   // New Getters automatically receive the latest value
 
Getter<Status> getter("shm://vehicle/status");
getter.listen([](auto& s) { use(s); });
getter.set_change_reporting(true);  // Trigger only on value change

🔧 Getting Started (Build)

cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j
ctest --test-dir build --output-on-failure
sudo cmake --install build

CMake integration:

# Specific modules
find_package(vlink REQUIRED COMPONENTS shm dds)
target_link_libraries(my_app PRIVATE vlink::vlink vlink::shm vlink::dds)
 
# All modules
find_package(vlink REQUIRED COMPONENTS all)
target_link_libraries(my_app PRIVATE vlink::all)
 
# Generated proto targets
vlink_generate_cpp(TARGET example_gen PROTO example1.proto example2.proto)
target_link_libraries(my_app PRIVATE example_gen)

See the CMake target list and the full Build Guide for details.

💻 Platform Support

Platform	Architecture	Compiler	Status
Linux	x86_64 / aarch64	GCC 9+ / Clang 10+	✅ Stable
Windows 10+	x86_64	MSVC 2019+ / MinGW	✅ Stable
macOS 10.15+	x86_64 / arm64	AppleClang 12+	🟡 Beta
Android	aarch64 / x86_64	NDK Clang r25+	✅ Stable
QNX 7.x/8.x	aarch64 / x86_64	QCC (QNX SDP)	✅ Stable

📁 Project Structure

vlink/
├── include/vlink/      Public headers (6 primitives + base + extensions + zerocopy)
├── src/                Core library implementation
├── modules/            12 transport backend implementations
├── cli/                9 command-line tools
├── proxy/              vlink-proxy executable + ProxyServer / ProxyAPI libraries
├── viewer/             Qt desktop visualization tool (default OFF, requires ENABLE_VIEWER=ON)
├── webviz/             vlink-foxglove / vlink-rerun bridge executables (default OFF)
├── c_api/              C API (data plane only, for Python/Rust/etc. FFI)
├── python_api/         nanobind Python bindings (default OFF, requires ENABLE_PYTHON_API=ON)
├── examples/           Usage examples (default OFF, 14 categories)
├── test/               doctest main test suite (vlink-test)
├── doc/                Documentation
├── tools/              Build, packaging, versioning helpers
├── cmake/              CMake toolchains and Find modules
├── thirdparty/         Third-party dependencies and patches
├── packup/             Release packaging assets
├── CMakeLists.txt      Top-level CMake entry
├── conanfile.py        Conan recipe
└── Android.bp          Android.bp (Soong build rules)

🤝 Contributing

Pull requests are welcome. Please read the PR Conventions before opening a PR.

📜 License

[Apache License 2.0](LICENSE) — free for commercial use.

*Author: Thun Lu thun..nosp@m.lu@z.nosp@m.ohoma.nosp@m.il.c.nosp@m.n*