trpc client request size limits?

[TRPCClientError: JSON Parse error: Unexpected token: <]

this.trpcClient = createTRPCProxyClient<TendrelAppRouter>({
      links: [
        loggerLink(
          enabled: _ => true
        }),
        httpBatchLink({
          url: stage.endpoint,
          headers: () => ({ bearer: this.workerAuthToken }),
        })
      ],
      transformer: superjson
    });
  }