Mine at Lazarus with the FlyTheElephant gateway

FlyTheElephant1/datum_gateway is a DATUM gateway for this chain: CONVOY's BLAKE2b code plus FlyTheElephant's own work. Its master gives every miner the pool's whole payout split (the 16 KB coinbase) and fits that coinbase to the block's weight and sigop limits, so a full split can never make your block invalid. It connects to Lazarus with no patch. FlyTheElephant also helps miners set up in our Discord #support. Thank you.

1. Your node. Bitcoin Knots 29.4.3 (older builds do not know the 180-day coinbase maturity rule from block 979,919 and can build blocks the network rejects), fully synced on this chain. In bitcoin.conf:

server=1
blake2b_headline=8-30 NYPost Deride And Conquer
blockmaxweight=736000
maxscriptsize=589
blocknotify=killall -USR1 datum_gateway

blockmaxweight leaves room for the split coinbase. maxscriptsize=589 keeps the large fake-multisig data transactions out of your blocks; stock Knots mines them by default. It is your node and your choice: the setting also declines very large multisig spends (about 5-of-7 and up), which other nodes still mine. Knots' default DNS seeds point at peers on the SHA-256 fork, so add a few addnode= lines from a current list for this chain (bitcoinxor.org/node, or CONVOY's guide); a list pasted weeks ago rots. maxtipage only mattered during the slow weeks after the fork and you can leave it out once you are synced.

2. Build the gateway. On Debian or Ubuntu (other systems: the repo's README):

sudo apt install cmake pkgconf libcurl4-openssl-dev libjansson-dev libsodium-dev libmicrohttpd-dev psmisc
git clone https://github.com/FlyTheElephant1/datum_gateway
cd datum_gateway
cmake . && make
./datum_gateway --test
./datum_gateway -c datum_gateway_config.json

There is also a Dockerfile in the repo; in Docker set notify_fallback to false and use blocknotify=wget -q -O /dev/null http://datum-gateway:7152/NOTIFY.

3. Config. A complete datum_gateway_config.json for Lazarus. Copy pool_pubkey from the DATUM tab below; set pool_address to your own address (it only receives value on work that is not pooled); point rpccookiefile or rpcuser/rpcpassword at your node.

{
  "bitcoind": {
    "rpccookiefile": "/home/you/.bitcoin/.cookie",
    "rpcurl": "http://127.0.0.1:8332",
    "notify_fallback": true
  },
  "stratum": { "listen_port": 23334, "vardiff_min": 4096 },
  "mining": {
    "pool_address": "bc1q…your address",
    "coinbase_tag_primary": "Lazarus",
    "coinbase_tag_secondary": "your name or rig"
  },
  "api": { "listen_port": 7152, "admin_password": "choose one" },
  "logger": { "log_level_console": 2 },
  "datum": {
    "pool_host": "datum.lazarus-xbt.xyz",
    "pool_port": 28915,
    "pool_pubkey": "the pubkey from the DATUM tab below",
    "pool_pass_workers": true,
    "pool_pass_full_users": true,
    "pooled_mining_only": true
  }
}

Leave vardiff_min at 4096: without it stock DATUM starts every session at 16384, and Prime cannot lower that.

4. Point your miners at the gateway, not at us: stratum+tcp://<your gateway's LAN IP>:23334, username youraddress.worker, password x. The part before the first . is who gets paid.

5. Check it. Within a minute your gateway shows under Gateways as v0.4.1-beta/<commit> with fee path DATUM, and your address appears under Miners after its first share. The gateway's own dashboard is on port 7152. Its log should say DATUM Server MOTD with our Proverbs line; a found block shows here with its split.

If it does not connect. DATUM not connected and configured for pooled mining only! Rejecting connection means the gateway has no pool session, so it turns miners away (their firmware then fails over to their backup pool): check pool_host, pool_port and that pool_pubkey is the whole key from this page; a wrong key never gets past the handshake. A tip stuck at 961,639 is an old Knots or peers on the SHA-256 fork. Refused in the log with an upgrade message means your node built a block the chain rejected; upgrade Knots and reconnect, and it lets you back in by itself.

What we measured. We ran this gateway against our own Prime and Knots 29.4.2 on regtest, most recently master 280cf54 on 9 October 2026, where blocks found by an Antminer A3 and by a generic miner each paid all 60 miners in the window: handshake and pubkey pinning, the split in every found block paying every miner in the window, address.worker and bare-address usernames, the 0% DATUM fee path, reconnects, Prime's template checks and refusals all pass. One thing does not, and it is shared by every C DATUM gateway today (iohzrd and CONVOY too): for a fraction of a second after each new block, and for as long as the pool's split is late, the gateway can hand out a job whose coinbase pays only the pool. A small patch fixes it by serving the empty subsidy-only job, or nothing, until the split is in. It is not in master yet (it still applies to 280cf54), so apply it yourself: datum-gateway-fte-late-coinbaser.patch (patch -p1 < it before cmake).