RosProvider

Creates and owns a single roslib.Ros connection and exposes it — along with its live status — to descendants via React context. Every other Hook in roshooks reads the connection from this provider, so it must wrap any part of the tree that uses them.

import { RosProvider } from "roshooks";

<RosProvider url="ws://localhost:9090">
  <App />
</RosProvider>;

Props

Prop	Type	Default	Description
url	string	—	The rosbridge server URL, e.g. "ws://localhost:9090".
autoConnect	boolean	true	Connect automatically on mount and whenever url changes.
transportFactory	ITransportFactory	roslib's default WebSocket transport	Overrides the transport used to connect — mainly useful for tests or WebRTC setups. See Testing.
onConnection	() => void	—	Called when the connection succeeds.
onClose	() => void	—	Called when the connection closes.
onError	(error: unknown) => void	—	Called on a connection error.
children	ReactNode	—	—

Behavior

• A single Ros instance is created once, on first render, and reused for the lifetime of the provider (changing unrelated props does not recreate it).
• When autoConnect is true, ros.connect(url) is called on mount and again whenever url changes; the previous connection is closed first.
• On unmount, the connection is closed and all internal event listeners are removed.
• Descendants read the connection and status with useRos (or the lower-level useRosContext).

See Connection Status for the full status state machine.

useRosContext()

import { useRosContext } from "roshooks";

const { ros, status, error } = useRosContext();

The context hook that useRos and every other Hook build on. Throws if called outside of a RosProvider. Prefer useRos unless you specifically need the raw context value.