specification.md

MQTT Topic Specification

Summary

Topic	Server Operations	Client Operations
work/precache	Publish	Subscribe
work/ondemand	Publish	Subscribe
result/precache	Subscribe	Publish
result/ondemand	Subscribe	Publish
cancel/precache	Publish	Subscribe
cancel/ondemand	Publish	Subscribe
client/address	Publish	Subscribe
heartbeat	Publish	Subscribe
statistics	Publish	Subscribe

Topics

work/precache , work/ondemand

These topics are used by the server to publish new work for clients. Clients can choose to subscribe to precache work, on-demand work, or both.

Message format:

block_hash,difficulty

Example:

BFEB8AA91D346E6EFBB41D11FD247E48E0BC0DBC183DDEB9F26F3A98AA17522F,ffffffc000000000

result/precache , result/ondemand

These topics are used by clients to publish work results for the server.

Message format:

block_hash,work_result,client_address

Example:

BFEB8AA91D346E6EFBB41D11FD247E48E0BC0DBC183DDEB9F26F3A98AA17522F,3108a2891093ce9e,nano_1dpowzkw9u6annz4z48aixw6oegeqicpozaajtcnjom3tqa3nwrkgsk6twj7

cancel/precache , cancel/ondemand

These topics are used by the server, when valid work is received, to alert clients they should cancel ongoing or future work for a hash.

Message format:

block_hash

Example:

BFEB8AA91D346E6EFBB41D11FD247E48E0BC0DBC183DDEB9F26F3A98AA17522F

cancel/precache , cancel/ondemand

These topics are used by the server, when valid work is received, to alert clients they should cancel ongoing or future work for a hash.

Message format:

block_hash

Example:

BFEB8AA91D346E6EFBB41D11FD247E48E0BC0DBC183DDEB9F26F3A98AA17522F

client/$client_address

These topics (one per client address) are used by the server to notify a client its work was accepted. Per-client statistics are sent here. Any client can subscribe to other clients' statistics.

Message format as example:

{
    "precache": 51230,
    "ondemand": 11757,
    "snapshot_precache": 33012,
    "snapshot_ondemand": 7893,
    "block_rewarded": "0FAD765D873CF9412A4A651D072D3AB3262E4EDC6727516EE70A1B2ED58ADADE"
}

The snapshot fields are updated when the server performs payouts. The block_rewarded field contains the latest block for which the client's work was accepted.

heartbeat

This topic has an empty message, and is used to alert clients and dashboards that there is an issue with the server (when heartbeats stop arriving). A message is sent roughly every second.

statistics

Provides complete statistics about services using DPoW, their work counters and public information. A message is sent every 5 minutes.

Message format as example:

{
    "services":
    {
        "public":
        [
            {
                "display": "Test Service",
                "website": "test.dpow.org",
                "precache": 213,
                "ondemand": 1543
            },
            (...other public services...)
        ],
        "private":
        {
            "count": 4,
            "precache": 13494,
            "ondemand": 11333
        }
    },
    "work":
    {
        "precache": 93512,
        "ondemand": 23351
    }
}

Information of private services is accumulated. count is the number of private services registered.