KeepAlive

Non standard but widely supported protocol extension. Miner send request with method keepalived to prevent connection timeout.

{
  "id": 2,
  "method": "keepalived",
  "params": {
    "id": "1be0b7b6-b15a-47be-a17d-46b2911cf7d0"
  }
}

{
  "id": 2,
  "jsonrpc": "2.0",
  "error": null,
  "result": {
    "status": "KEEPALIVED"
  }
}

XMRig specific extension

To make miner works with proxy without additional setup added new item keepalive for extensions field of login reply.

{
  "id": 1, "jsonrpc": "2.0", "error": null,
  "result": {
    "id": "...",
    "job": {
      "blob": "...", "job_id": "...", "target": "...", "id": "...", "algo": "..."
    },
    "extensions": ["nicehash", "keepalive"],
    "status": "OK"
  }
}