proxy
Proxy address the Agent connects to. Accepts either hostname (port defaults to agent.proxy.port from config, normally 50051) or hostname:port.
Accepts a comma-separated list for high availability — proxy1:50051,proxy2:50051. The agent tries them in order, first successful connection wins, and rotates on a failed connect. A single value behaves exactly as it always has.
Empty means "fall back to PROXY_HOSTNAME env var, then agent.proxy.endpoints from config, then agent.proxy.hostname[:port]".