Mining

Tesserax blocks are mined on CPUs with RandomTESS, the Tesserax configuration of RandomX v2. A block pays its miner 0.85 TESS (halving every 7 000 000 blocks) plus all the fees and tips of its transactions; nothing is burned.

There are two ways to mine:

• the built-in miner of the node (--mine), the simplest;
• XMRig with the rx/tess algorithm, connected to the stratum server of a node (--stratum). XMRig is several times faster than the built-in miner on the same CPU.

RandomTESS

RandomTESS is RandomX v2 (384 instructions per program, the v2 CFROUND, AES and dataset prefetch changes, and the v2 commitment) with:

Parameter	RandomX	RandomTESS
Argon2 salt	RandomX\x03	RandomTESS\x01
IROR_R / IROL_R frequencies	8 / 2	6 / 4
FADD_M / FSUB_M frequencies	5 / 5	4 / 6

Memory requirements are those of RandomX: 2 GiB of dataset to mine at full speed (256 MiB in light mode), 256 MiB to verify.

The work input of a block is 43 bytes: the hash of the header without its seal, then an 11-byte nonce. Miners iterate the last 4 bytes of the nonce, at offset 39 as in Monero; the 7 bytes before are an extra nonce set by the stratum server for each connection.

The proof-of-work value is the RandomX v2 commitment Blake2b-256(input || hash), where hash is the RandomTESS hash of the input under the key of the block. The seal of a block carries the nonce and the hash, so a node checks the commitment against the difficulty with one Blake2b before it runs the virtual machine: an invalid block costs nothing to reject.

The key is the hash of a past block: it changes every 2048 blocks (about 10 hours), 64 blocks after the key block, so that miners prepare the next dataset in advance.

Built-in miner

tesserax --chain <spec> --mine --author <address>

--author is the account credited with the mined blocks. --mining-threads N sets the number of threads (all cores by default) and --mining-light mines with 256 MiB instead of 2 GiB, about ten times slower.

XMRig

The node serves block templates to XMRig over stratum:

tesserax --chain <spec> --stratum --author <address>

The server listens on 127.0.0.1:3333; --stratum 0.0.0.0:3333 accepts rigs of the local network. It has no authentication: keep it behind a firewall, on a private network. --stratum-max-miners limits the number of connected rigs (256 by default). --mine and --stratum can be combined.

Every block mined through the server credits --author. The login of a rig is its name (rig1), or the address of the author; the server refuses another address, so that a rig never mines to a node believing that the rewards go elsewhere.

Download the rx/tess miner, a fork of XMRig 6.26.0, from the downloads: static binaries for Linux (x64, arm64), macOS (Apple Silicon, Intel) and Windows (x64), with their SHA-256 in SHA256SUMS. Every binary is checked against the reference RandomTESS implementation, in light and fast mode, before it is published. On macOS, allow it once with xattr -d com.apple.quarantine xmrig.

Hive OS and RaveOS

Rigs managed by Hive OS or RaveOS install the same miner as a custom miner, from its release:

• Hive OS: in a flight sheet, the miner Custom, with the installation URL of tesserax-<version>.tar.gz (the - of the version as _), the wallet and worker template %WAL%.%WORKER_NAME% with your Tesserax address as wallet, the stratum address of the pool as pool URL, and x as password. Optional XMRig settings go in JSON in the extra config, such as "randomx": {"mode": "light"}. The dashboard shows the hashrate, shares and CPU temperature of each rig.
• RaveOS: in Custom mining, the archive tesserax-raveos-<version>.zip as a miner, a coin TESS with the algorithm rx/tess, and the pool, its login being your address, a dot and the name of the rig.

The README of the miner details every field.

Or build it:

git clone https://github.com/Tesserax-foundation/tesserax-miner.git
cd tesserax-miner && mkdir build && cd build
cmake .. -DWITH_OPENCL=OFF -DWITH_CUDA=OFF
make -j$(nproc)

and point it to the node:

./xmrig -o 127.0.0.1:3333 -u rig1 -a rx/tess

The fork has no developer fee: XMRig normally gives 1% of the hashrate to its developers, this build gives 0% whatever the donate-level option says. RandomTESS runs on CPUs only; the GPU backends of XMRig do not implement RandomX v2 and are disabled for rx/tess.

Each rig gets a job whose target is the block difficulty: XMRig submits a share only when it finds a block. The node logs Block #N mined by stratum miner rig1 for each of them.

A share found for a block that was mined in the meantime is answered Stale share: it cannot make a block any more. Stale shares stay rare when the node imports blocks quickly; a machine that runs both the node and XMRig needs about 3 GiB of free memory for them (2 GiB of dataset, 256 MiB of verification cache, the node itself), or XMRig in light mode ("randomx": {"mode": "light"}).

Measured on an Apple M1 (8 GiB), 4 threads: about 600 H/s with XMRig against about 100 H/s with the built-in miner.

Protocol

The server speaks the stratum protocol of RandomX pools (JSON-RPC, one message per line):

• login (login, pass, agent, algo, rigid) returns a session id and a job;
• job is pushed whenever the block template changes: blob (43 bytes, hex), job_id, target (64-bit little-endian, hex), algo (rx/tess), height, seed_hash (the RandomTESS key);
• submit (id, job_id, nonce: 4 bytes hex, result: the commitment, commitment: the RandomTESS hash) returns OK when the block is imported;
• keepalived keeps the connection open; an idle connection closes after 5 minutes.

Every job also carries difficulty, the exact block difficulty as a decimal string.

A mining pool logs in with "mode": "pool". Its jobs then carry reserved_offset (35) and reserved_size (4): the node fixes the first 3 bytes of the extra nonce, the pool sets the next 4 for each of its rigs, and submits the blocks they find with that extra_nonce (4 bytes, hex). The extra nonces of pools and of rigs never overlap. See the mining pool.

tesserax-pool is a mining pool built on this mode: PPLNS rewards, verified shares and automatic payouts. See the mining pool.