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ROS 2 Interoperability

ros-z nodes — whether written in Rust, Python, or Go — speak the same Zenoh wire protocol as rmw_zenoh_cpp, the official ROS 2 middleware plugin for Zenoh. This means they interoperate transparently: a Go subscriber can receive messages from a ROS 2 C++ talker, a Python publisher can send to a Rust listener, and so on.

Prerequisites

  • A ROS 2 installation with rmw_zenoh_cpp and demo_nodes_cpp
  • A Zenoh router running on localhost:7447 (see Networking)

How It Works

All participants connect to the same Zenoh router on the local machine.

graph LR
    talker["demo_nodes_cpp<br>talker"] --> rmw["rmw_zenoh_cpp"] --> router(["Zenoh router<br>localhost:7447"])
    router <-->|Zenoh| rust["Rust<br>(ros-z)"]
    router <-->|Zenoh| python["Python<br>(ros-z-py)"]
    router <-->|Zenoh| go["Go<br>(ros-z-go)"]

Note

The Zenoh router can be rmw_zenohd, zenohd, cargo run --example zenoh_router, or Docker. See Networking for all options.

Requirements for successful message exchange:

  • Both sides must use the same message type with matching RIHS01 type hashes
  • ROS 2 nodes must use rmw_zenoh_cpp (export RMW_IMPLEMENTATION=rmw_zenoh_cpp)

Warning

If type hashes differ (e.g. mismatched message definitions), nodes silently drop messages. Enable RUST_LOG=ros_z=debug to inspect the hash in the key expression and compare with the ROS 2 side. See Troubleshooting for diagnosis steps.

Setup

# Terminal 1 — router
ros2 run rmw_zenoh_cpp rmw_zenohd

# Terminal 2 — ROS 2 talker
export RMW_IMPLEMENTATION=rmw_zenoh_cpp
ros2 run demo_nodes_cpp talker

# Terminal 3 — ros-z listener (see Rust / Python / Go below)

Rust

cargo run --example demo_nodes_listener

For more detail on publisher/subscriber patterns see Pub/Sub.

Python

cd crates/ros-z-py
source .venv/bin/activate
python examples/topic_demo.py -r listener

Or go the other way — Python publishes, ROS 2 listens:

python examples/topic_demo.py -r talker
# On ROS 2 side:
ros2 topic echo /chatter std_msgs/msg/String

For more detail see Python Bindings.

Go

just -f crates/ros-z-go/justfile run-example subscriber

For more detail see Go Quick Start.