localParticipant.publishData crashing server for messages longer than around 65000 bytes

[sergii-kamenskyi]

I am using the standard function to send chat messages from the node server to the browser client.
It is part of "agent" code.

  const messageData = {
    id: message.id || crypto.randomUUID(),
    message: message.message,
    role: message.role,
    timestamp: message.timestamp || Date.now(),
  }
  const encoder = new TextEncoder()
  const data = encoder.encode(JSON.stringify(messageData))
  localParticipant.publishData(data, {
    reliable: true,
    topic: chatMessageTopic,
  })

if the data size exceeds some limit (looks like 16bit: 65535 bytes) the server crashes with timeout somewhere inside binary (rust?) code.
This limitation never stated anywhere and never checked.

I know that we should not abuse the size of the single messages, but for my use case (some technical data), the message could be up to 1mb.
Anyway, it would be nice to clarify this and make error message less obscure. (I spent days to find the reason)

The error:

[01:49:11.509] WARN (765776): process orphaned, shutting down
    jobID: "AJ_dWG4R3uvsMGr"
/home/sergii/work/zolar-assistant/node_modules/@livekit/rtc-node/src/participant.ts:141
      throw new Error(cb.error);
            ^


Error: engine: connection error: could not establish publisher connection: timeout
    at LocalParticipant.publishData (/home/sergii/work/zolar-assistant/node_modules/@livekit/rtc-node/src/participant.ts:141:13)

Node.js v22.10.0
[01:49:25.451] WARN (769111): job process exited unexpectedly
    err: {
      "type": "Error",
      "message": "Channel closed",
      "stack":
          Error [ERR_IPC_CHANNEL_CLOSED]: Channel closed
              at target.send (node:internal/child_process:753:16)
              at Timeout._onTimeout (/home/sergii/work/zolar-assistant/node_modules/@livekit/agents/dist/ipc/proc_job_executor.js:47:18)
              at listOnTimeout (node:internal/timers:594:17)
              at process.processTimers (node:internal/timers:529:7)
      "code": "ERR_IPC_CHANNEL_CLOSED"
    }

Versions:
"@livekit/agents": "^0.6.0",
"rts-node": "0.12.2",
"@livekit/rtc-node-linux-x64-gnu": "0.12.2",