Errors - Radion

The SDK groups its errors in a small tree. TypeScript and Python use the same set of classes. Rust uses one RadionError enum with matching variants.

Type / variant	Raised when
`RadionError`	The base class for every SDK error (the enum itself in Rust).
`RadionConnectionError` / `RadionError::Connection`	You used the client in a bad state (for example, no key, or used after `close`).
`RadionServerError` / `RadionError::Server`	The server sent an `error` frame. Holds `code`, `channel`, and `id`.
`RadionError::Transport` (Rust)	The WebSocket transport under the hood failed.

The SDK does not throw server errors or handler errors from a method. It sends them to the error lifecycle event instead.

import { RadionConnectionError, RadionServerError } from "@radion-app/sdk";

radion.realtime.onLifecycle("error", (err) => {
  if (err instanceof RadionServerError) {
    console.error("server error", err.code, err.channel, err.id);
  } else if (err instanceof RadionConnectionError) {
    console.error("connection error", err.message);
  }
});

from radion import RadionConnectionError, RadionServerError

@radion.realtime.on_lifecycle("error")
async def errored(err):
    if isinstance(err, RadionServerError):
        print("server error", err.code, err.channel, err.id)
    elif isinstance(err, RadionConnectionError):
        print("connection error", err)

use futures_util::StreamExt;
use radion_sdk::realtime::LifecycleEvent;
use radion_sdk::RadionError;

let mut lifecycle = radion.realtime.lifecycle();
while let Some(event) = lifecycle.next().await {
    if let LifecycleEvent::Error(err) = event {
        match err {
            RadionError::Server { code, channel, id, .. } => {
                eprintln!("server error {code:?} {channel:?} {id:?}");
            }
            RadionError::Connection(message) => eprintln!("connection error {message}"),
            RadionError::Transport(message) => eprintln!("transport error {message}"),
            _ => {}
        }
    }
}

Server error codes

RadionServerError.code matches the server’s error frames. Common codes:

Code	Meaning
`unknown_channel`	The channel name is unknown, or a required filter is missing.
`subscription_limit`	You went over your plan’s subscription limit for the connection.
`lagged`	You read too slowly and fell behind the buffer, so some events were dropped.
`key_revoked`	The API key was revoked, so the connection is closed.
`revalidation_failed`	The key could not be checked again, so the connection is closed.

Treat key_revoked and revalidation_failed as fatal: call close() and stop. For normal drops, the client reconnects on its own.

​Server error codes

Server error codes