RangeError: Max payload size exceeded on second user query

[pncnfb]

Hi everybody,

I’m using AG UI with Strands Agents, and on the backend I have an agent connected to an MCP PostgreSQL.

Here’s the issue:

The first user query works perfectly.
When I try a second user query, the app crashes and I get the following log:

⨯ uncaughtException: RangeError: Max payload size exceeded
    at ignore-listed frames {
  code: 'WS_ERR_UNSUPPORTED_MESSAGE_LENGTH'
}

It seems the error comes from the WebSocket layer in AG UI.
Max payload size exceeded suggests the message being sent back (or forth) exceeds the allowed size.
WS_ERR_UNSUPPORTED_MESSAGE_LENGTH points to a WebSocket protocol issue.

My questions are:

• What is the maximum payload size supported in AG UI WebSockets?
• Is there a way to increase this limit, or split/stream large responses?
• Has anyone experienced this crash when the backend agent returns larger results (e.g., querying PostgreSQL)?
• Are there recommended best practices for handling multi-turn conversations with potentially large payloads?

Thanks in advance for any guidance!