Stratum RPC Protocol

This document describes the current Stratum RPC protocol implemented in mwc.

Messages

In this section, we detail each message and the potential response.

getjobtemplate method

A message initiated by the miner. Miner can request a job with this message.

Request

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"getjobtemplate"
params	null

Example:

{
   "id":"2",
   "jsonrpc":"2.0",
   "method":"getjobtemplate",
   "params":null
}

The response can be of two types:

OK response

Example:

{
   "id":"0",
   "jsonrpc":"2.0",
   "method":"getjobtemplate",
   "result":{
      "difficulty":1,
      "height":13726,
      "job_id":4,
      "pre_pow":"00010000000000003c4d0171369781424b39c81eb39de10cdf4a7cc27bbc6769203c7c9bc02cc6a1dfc6000000005b50f8210000000000395f123c6856055aab2369fe325c3d709b129dee5c96f2db60cdbc0dc123a80cb0b89e883ae2614f8dbd169888a95c0513b1ac7e069de82e5d479cf838281f7838b4bf75ea7c9222a1ad7406a4cab29af4e018c402f70dc8e9ef3d085169391c78741c656ec0f11f62d41b463c82737970afaa431c5cabb9b759cdfa52d761ac451276084366d1ba9efff2db9ed07eec1bcd8da352b32227f452dfa987ad249f689d9780000000000000b9e00000000000009954"
   }
}

Error response

If the node is syncing, it will send the following message:

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"getjobtemplate"
error	{"code":-32701,"message":"Node is syncing - Please wait"}

Example:

{
   "id":"10",
   "jsonrpc":"2.0",
   "method":"getjobtemplate",
   "error":{
      "code":-32000,
      "message":"Node is syncing - Please wait"
   }
}

job method

A message initiated by the Stratum server. Stratum server will send job automatically to connected miners. The miner SHOULD interrupt current job if job_id = 0, and SHOULD replace the current job with this one after the current graph is complete.

Request

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"job"
params	Int difficulty, height, job_id and string pre_pow

Example:

{
   "id":"Stratum",
   "jsonrpc":"2.0",
   "method":"job",
   "params":{
      "difficulty":1,
      "height":16375,
      "job_id":5,
      "pre_pow":"00010000000000003ff723bc8c987b0c594794a0487e52260c5343288749c7e288de95a80afa558c5fb8000000005b51f15f00000000003cadef6a45edf92d2520bf45cbd4f36b5ef283c53d8266bbe9aa1b8daaa1458ce5578fcb0978b3995dd00e3bfc5a9277190bb9407a30d66aec26ff55a2b50214b22cdc1f3894f27374f568b2fe94d857b6b3808124888dd5eff7e8de7e451ac805a4ebd6551fa7a529a1b9f35f761719ed41bfef6ab081defc45a64a374dfd8321feac083741f29207b044071d93904986fa322df610e210c543c2f95522c9bdaef5f598000000000000c184000000000000a0cf"
   }
}

Response

No response is required for this message.

keepalive method

A message initiated by the miner in order to keep the connection alive.

Request

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"keepalive"
params	null

Example:

{
   "id":"2",
   "jsonrpc":"2.0",
   "method":"keepalive",
   "params":null
}

Response

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"keepalive"
result	"ok"
error	null

Example:

{
   "id":"2",
   "jsonrpc":"2.0",
   "method":"keepalive",
   "result":"ok",
   "error":null
}

login method

A message initiated by the miner. Miner can log in on a mwc Stratum server with a login, password and agent (usually statically set by the miner program).

Request

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"login"
params	Strings: login, pass and agent

Example:

{
   "id":"0",
   "jsonrpc":"2.0",
   "method":"login",
   "params":{
      "login":"login",
      "pass":"password",
      "agent":"mwc-miner"
   }
}

The response can be of two types:

OK response

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"login"
result	"ok"
error	null

Example:

{
   "id":"1",
   "jsonrpc":"2.0",
   "method":"login",
   "result":"ok",
   "error":null
}

Error response

Not yet implemented. Should return error -32500 "Login first" when login is required.

status method

A message initiated by the miner. This message allows a miner to get the status of its current worker and the network.

Request

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"status"
params	null

Example:

{
   "id":"2",
   "jsonrpc":"2.0",
   "method":"status",
   "params":null
}

Response

The response is the following:

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"status"
result	String id. Integers height, difficulty, accepted, rejected and stale
error	null

Example:

{
   "id":"5",
   "jsonrpc":"2.0",
   "method":"status",
   "result":{
      "id":"5",
      "height":13726,
      "difficulty":1,
      "accepted":0,
      "rejected":0,
      "stale":0
   },
   "error":null
}

submit method

A message initiated by the miner. When a miner find a share, it will submit it to the node.

Request

The miner submit a solution to a job to the Stratum server.

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"submit"
params	Int edge_bits,nonce, height, job_id and array of integers pow

Example:

{
   "id":"0",
   "jsonrpc":"2.0",
   "method":"submit",
   "params":{
      "edge_bits":29,
      "height":16419,
      "job_id":0,
      "nonce":8895699060858340771,
      "pow":[
         4210040,10141596,13269632,24291934,28079062,84254573,84493890,100560174,100657333,120128285,130518226,140371663,142109188,159800646,163323737,171019100,176840047,191220010,192245584,198941444,209276164,216952635,217795152,225662613,230166736,231315079,248639876,263910393,293995691,298361937,326412694,330363619,414572127,424798984,426489226,466671748,466924466,490048497,495035248,496623057,502828197, 532838434
         ]
   }
}

The response can be of three types.

OK response

The share is accepted by the Stratum but is not a valid cuck(at)oo solution at the network target difficulty.

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"submit"
result	"ok"
error	null

Example:

{
   "id":"2",
   "jsonrpc":"2.0",
   "method":"submit",
   "result":"ok",
   "error":null
}

Blockfound response

The share is accepted by the Stratum and is a valid cuck(at)oo solution at the network target difficulty.

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"submit"
result	"block - " + hash of the block
error	null

Example:

{
   "id":"6",
   "jsonrpc":"2.0",
   "method":"submit",
   "result":"blockfound - 23025af9032de812d15228121d5e4b0e977d30ad8036ab07131104787b9dcf10",
   "error":null
}

Error response

The error response can be of two types: stale and rejected.

Stale share error response

The share is a valid solution to a previous job not the current one.

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"submit"
error	{"code":-32503,"message":"Solution submitted too late"}

Example:

{
   "id":"5",
   "jsonrpc":"2.0",
   "method":"submit",
   "error":{
      "code":-32503,
      "message":"Solution submitted too late"
   }
}

Rejected share error responses

Two possibilities: the solution cannot be validated or the solution is of too low difficulty.

Failed to validate solution error

The submitted solution cannot be validated.

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"submit"
error	{"code":-32502,"message":"Failed to validate solution"}

Example:

{
   "id":"5",
   "jsonrpc":"2.0",
   "method":"submit",
   "error":{
      "code":-32502,
      "message":"Failed to validate solution"
   }
}

Share rejected due to low difficulty error

The submitted solution is of too low difficulty.

Field	Content
id	ID of the request
jsonrpc	"2.0"
method	"submit"
error	{"code":-32501,"message":"Share rejected due to low difficulty"}

Example:

{
   "id":"5",
   "jsonrpc":"2.0",
   "method":"submit",
   "error":{
      "code":-32501,
      "message":"Share rejected due to low difficulty"
   }
}

Error Messages

mwc Stratum protocol implementation contains the following error message:

Error code	Error Message
-32000	Node is syncing - please wait
-32500	Login first
-32501	Share rejected due to low difficulty
-32502	Failed to validate solution
-32503	Solution Submitted too late
-32600	Invalid Request
-32601	Method not found

Miner behavior

Miners SHOULD, MAY or MUST respect the following rules:

• Miners SHOULD randomize the job nonce before starting
• Miners MUST continue mining the same job until the server sends a new one, though a miner MAY request a new job at any time
• Miners MUST NOT send an rpc response to a job request from the server
• Miners MAY set the RPC "id" and expect responses to have that same id
• Miners MAY send a keepalive message
• Miners MAY send a login request (to identify which miner finds shares / solutions in the logs), the login request MUST have all 3 params.
• Miners MUST return the supplied job_id with submit messages.

Reference Implementation

The current reference implementation is available at mimblewimble/mwc-miner.