STRATUM_EXT.md

Stratum protocol extensions

1. Mining algorithm negotiation

Subset of protocol extensions, used to negotiate algorithm between miner and pool/proxy. All extensions is backward compatible with standart stratum protocol.

1.1. Miner defined algorithms list

Miner should send list of algorithms supported. Multiple algorithms in list meant miner can switch algorithms in runtime.

{
  "id": 1, "jsonrpc": "2.0", "method": "login",
  "params": {
    "login": "...", "pass": "...", "agent": "...",
    "algo": ["cn", "cn/0", "cn/1", "cn/xtl"]
  }
}

In case if miner not support dynamic algorithm change, miner should send list with one item, for example "algo": ["cn-heavy"], pool/proxy should provide work for selected algorithm or send error.

1.2. Extended job object

To each job object pool/proxy should add additional field algo.

{
  "id": 1, "jsonrpc": "2.0", "error": null,
  "result": {
    "id": "...",
    "job": {
      "blob": "...", "job_id": "...", "target": "...", "id": "...",
      "algo": "cn/r"
    },
    "status": "OK"
  }
}

{
  "jsonrpc": "2.0", "method": "job",
  "params": {
    "blob": "...", "job_id": "...", "target": "b88d0600", "id": "...",
    "algo": "cn/r"
  }
}

If miner not support algorithm connection should be closed by miner to initiate switch to backup pool.

1.3. Algo extension

This extension is backward compatible with xmr-stak extended mining statistics. First, pool should add algo to extensions list:

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

Second, miner add fields algo to submit request.

{
  "id": 2, "jsonrpc": "2.0", "method": "submit",
  "params": {
    "id": "...", "job_id": "...", "nonce": "...", "result": "...",
    "algo": "cn/1"
  }
}

1.4 Algorithm names and variants

• https://github.com/xmrig/xmrig/blob/master/doc/ALGORITHMS.md#algorithm-names

Rig identifier

User defined rig identifier. Optional field rigid in login request. More details: fireice-uk/xmr-stak#849

Extended mining statistics

More details: fireice-uk/xmr-stak#66