c2pool — P2Pool rebirth in C++

C++ reimplementation of forrestv/p2pool targeting the V36 share format, with per-coin binaries for six parent chains and their merged-mining children: Litecoin (flagship — LTC + DOGE, PEP, BELLS, LKY, JKC, SHIC), Bitcoin (+ Namecoin), DigiByte (Scrypt), Bitcoin Cash, Dash, and BIP-110 (the Bitcoin Knots BLAKE2b minority hard fork — embedded daemonless, experimental). See Supported chains for the full matrix and status.

Bitcoin wiki: https://en.bitcoin.it/wiki/P2Pool

Original forum thread: https://bitcointalk.org/index.php?topic=18313

Daemonless Dash

c2pool-dash builds valid Dash mainnet blocks from embedded coin-state. The deterministic masternode list, LLMQ quorums, ChainLocks and the DIP-4 coinbase are reconstructed inside c2pool. No Dash Core node is required on the serve path. Blocks built this way have been accepted on Dash mainnet, including the pool development-fee split. A bare c2pool-dash --run is daemonless: with no --coin-rpc given, every embedded serving lever defaults ON (src/c2pool/main_dash.cpp banner, "ALL embedded serving levers default ON when NO dashd arm is given"; resolver in src/impl/dash/coin/good_citizen_defaults.hpp). The public node dash.voidbind.com runs this posture with no dashd on the host. A node started with --coin-rpc H:P keeps dashd as the reward-safe fallback arm — the operator's hotel deployment still runs dashd-attached — so both postures are supported by the same binary. The remaining work is the daemonless-finalize item below (retiring the --coin-rpc fallback entirely). See Per-binary launch reference for the flags.

Governance

Daemonless-Dash finalization has a funding proposal in Dash on-chain governance. The c2pool-daemonless-finalize proposal is in its voting phase; masternode operators can vote on it before the next superblock.

• DashCentral: https://www.dashcentral.org/p/c2pool-daemonless-finalize

• Governance object: fa758340f1bd2391d17bb43667f76c5d9070d737b68e018e42ed75b09c6ba631

• Vote from a masternode:

  dash-cli gobject vote-many fa758340f1bd2391d17bb43667f76c5d9070d737b68e018e42ed75b09c6ba631 funding yes
  

Funding requires net yes votes equal to 10 percent of enabled masternodes by the next superblock.

Daemonless BIP-110

c2pool-bip110 follows the BLAKE2b hard-fork chain over coin P2P with no bitcoind on the serve path. It is an embedded SPV header-follower: below height 961640 it validates SHA256d, and at/after the fork it validates the byte-exact BLAKE2b proof-of-work of the 164-byte v2 header — a SHA256d block past the fork is rejected, so the node tracks the BLAKE2b chain rather than the higher-work canonical Bitcoin chain. A known-answer test reproduces the canonical hash of live fork block 961640 (a block the fork network mined, not c2pool). This fork-following node is on master and is running live: bip110.voidbind.com is synced to the BLAKE2b fork tip.

The mining and reward-safe daemonless mempool-serving stack — Stratum-v1 work source, block assembler, and fail-closed reward-safety cross-checks (coinbasevalue == subsidy + fees, committed tx-merkle/txcount, refuse-to-serve on mismatch, submit-side merkle re-verify), plus the 0.1% author-donation split — is on master (merged via #1439). The live node at bip110.voidbind.com serves the fork mempool and accepts Stratum miners at stratum+tcp://bip110.voidbind.com:9336, behind a full coin-generic dashboard.

The value of this lane is strategic, not revenue: BIP-110 is a minority fork whose coin is effectively unlisted (block reward ≈ 0 in fiat), and mining a demo block requires renting BLAKE2b (Sia-algorithm) hashrate. The goal is to be a working decentralized pool on a fresh fork — a P2Pool-style alternative to centralized fork-mining gateways — not an earnings lane. This lane imports zero Dash consensus machinery; it is Bitcoin-native.

bip110.voidbind.com is part of the voidbind daemonless-standalone fleet — public pools that run with no coin daemon on the serve path: btc.voidbind.com, bch.voidbind.com, dgb.voidbind.com, dash.voidbind.com, and bip110.voidbind.com.

Mining (experimental, live): point a BLAKE2b (Sia-algorithm) miner at stratum+tcp://bip110.voidbind.com:9336 with username <BIP-110-address>.<worker> and any password. Daemonless standalone node on the BLAKE2b fork; block reward is effectively zero today (coin unlisted) — a decentralized-pool proof, not a revenue venue.

Supported chains

c2pool builds one binary per parent chain (c2pool-<coin>). Several parents also merge-mine AuxPoW child chains in the same coinbase.

Parent chain	Algorithm	Merged-mining children	Status
Litecoin (LTC)	Scrypt	DOGE, PEP, BELLS, LKY, JKC, SHIC — external daemons	Production (V36; live LTC+DOGE blocks) — c2pool-ltc
Bitcoin (BTC)	SHA256d	Namecoin (NMC)	Live, daemonless (c2pool-btc --coin-p2p-discover; btc.voidbind.com); NMC embedded merged mining in development
DigiByte (DGB)	Scrypt¹	DOGE (embedded, -DAUX_DOGE)	Live, daemonless (c2pool-dgb --run --coin-p2p-discover; dgb.voidbind.com) — mainnet only, no testnet mode
Bitcoin Cash (BCH)	SHA256d	—	Live, daemonless (c2pool-bch --pool; bch.voidbind.com)
Dash (DASH)	X11	—	Live, daemonless (c2pool-dash --run; dash.voidbind.com); dashd-attached posture via --coin-rpc still supported
BIP-110 (Knots BLAKE2b fork)	BLAKE2b² (SHA256d until height 961640)	—	Experimental (new fork; daemonless embedded; live on bip110.voidbind.com) — c2pool-bip110 --run

"Live" means a public voidbind node runs that per-coin binary with no coin daemon on the serve path. It is not a production-maturity claim: only the LTC line has the crossing-soak record behind it. Each binary's real flag surface is in Per-binary launch reference.

¹ DigiByte is a MultiAlgo chain; c2pool runs its Scrypt algorithm as a standalone parent — it is not an AuxPoW child of Litecoin.

² BIP-110 is a minority Bitcoin hard fork (Bitcoin Knots): its proof-of-work switches SHA256d→BLAKE2b at block height 961640 with a one-off difficulty reset, and it uses a reduced block weight of 800000 WU (RDTS). It shares Bitcoin mainnet's network magic and port until the fork; fork peers advertise NODE_BLAKE2B (service bit 28).

Status & Maturity — read this before evaluating

c2pool is a decentralized mining-pool codebase and the home of the v37 research line (Roundabout / Work Receipts / MRR). This section states, plainly, what does and does not yet exist, so the work can be judged on what it actually is.

v37 is design- and prototype-stage. Do not run it in production.

What exists

• A formally specified settlement/lanes core: TLA⁺ specs, model-checked with TLC (green over the bounded configurations checked in). This is a proof over a model, not evidence at scale.
• A v37 engine consumer tree implemented in C++ under src/c2pool/v37/ — the Work Receipts / Roundabout settlement pipeline as a reference/prototype engine behind CI, not a production node. Merged behind CI: the W1 O1 executor and W2 receipt ingestion (admission-first, carrier-position credit — PR #1483), the W4 prerequisites (identity view + read-at-version ring — PR #1485), W4 per-lane settlement (OWED-ledger fold + O2 cut + O5.5 — PR #1486), W5 coinbase assembly (oldest-owed-first K_fair + h_min carry + §13 root — PR #1487), and W3 carrier relay over the v36 p2p (wire extension + R_MAX — PR #1484). W6 persistence / restart-recovery is a reviewed draft, not landed (PR #1506).
• An isolated "Family B: XMR lane" (Monero / RandomX) under src/impl/xmr/, which does not touch the v37 consensus digest. Merged: the lane foundation (scaffold + vendored RandomX + X0 — PR #1500), buildable KAT-tested primitives (RandomX CI-gated — PR #1502), the monerod adapter + descriptor-finalize + receipt envelope (PR #1503), and stratum + FCMP-fenced coinbase-settlement + carrier wire (PR #1507). Goldens, real-RandomX verify, and the end-to-end KAT are merged (PR #1512); a single-node stagenet daemon is live (monerod-bound, PRs #1520 / #1529). Multi-node canonical payees + section-13 state root are a reviewed draft (PR #1551).
• Reference prototypes under proto/ (TLA⁺, MRR refimpl + goldens, the M4 sync feasibility harness, testbeds) and the v37 design-track spec/headers under src/sharechain/v37/. These are for study and reproduction, not deployment.
• The production multi-coin pool code (v36 line) that c2pool actually runs.

What does NOT yet exist — the honest gaps

• Not wired into a live node. The v37 engine exists as a reference/prototype behind CI; it is not connected to a live production node lifecycle for settlement. The F1 finalize-driver obligation is dormant — no production finalize caller is wired — so nothing settles on a live network today.
• No public v37 testnet. There is no running v37 network; the engine and lanes exercise simnet / loopback only. The runnable v37 artifacts are the engine tree and the prototypes above.
• No performance benchmark. The only performance artifact is a Python feasibility harness (M4). There is no benchmark of the real engine; throughput, latency, and scaling claims are unproven until one exists.
• XMR lane is single-node stagenet. Its RandomX verify runs CI-gated in light mode and against a live monerod-stagenet single node (PRs #1520 / #1529); the XMR PayoutDescriptor kind-bytes (0x10 / 0x11) are activated add-only (PR #1518). The remaining gaps are multi-node consensus (PR #1551, draft) and mainnet, which stays double-fenced.
• No token, no production deployments. There is no v37 token, and nothing v37 is deployed in production.
• Formal ≠ empirical. Model-checking bounds behavior over small configurations; it does not substitute for a benchmark or a live network.

v36 consensus note

• In July 2026 the LTC v36 line hit a consensus incident: specific false-activation modes of the AutoRatchet (an automatic protocol-upgrade latch) could trip on absence-as-assent and flap without hysteresis, desynchronizing the share chain. Those specific modes were caught and are now guarded by regression tests — see commit a7e5b29b8 (LTC ratchet mode-2 false-activation guard, PR #930) and its C5 regression KATs. A deeper redesign — deterministic ancestry-depth activation with hysteresis and chain self-heal, to close the whole class rather than the known modes — is in progress on the design track and not yet landed. We do not claim the class is fully closed.
• Donation script (legacy key, disclosed): the v36 donation output currently uses a P2SH script that inherits a legacy p2pool donation key from the upstream codebase. This is not an endorsement by, or involvement of, any third party — it is inherited code. It is scheduled for replacement with a c2pool-only script in v37. v36 blocks already produced with the inherited script are immutable consensus history and cannot be retroactively changed; the clean script becomes the default at the v37 boundary.

v36 ratchet complete — the last generation shared with Python p2pool

• The LTC line has ratcheted to V36. As of August 2026 the live Litecoin sharechain signals 100% V36 across the sampling window, and c2pool nodes produce and validate V36 PPLNS shares on the shared LTC+DOGE chain alongside the remaining Python p2pool v36 nodes. V36 is now the operating generation, not a transition target.
• V36 is the end of the line for the Python implementation. The Python p2pool is maintained only for the V36 sharechain it already interoperates with; no further Python protocol development is planned. V36 is the final share format shared between the Python codebase and c2pool (C++).
• v37 is C++ only. The next generation — Work Receipts and the MRR Roundabout settlement/lanes core — is being built exclusively in c2pool. There is no Python v37, and the v37 sharechain does not interoperate with Python p2pool. v37 remains design- and prototype-stage per the notes above and must not be run in production.

CI / repo state

• The v37 research line is merged to master (PR #809, "V37 dev"), and the v37 engine consumer tree (src/c2pool/v37/, W1–W5) and the isolated XMR Family-B lane (src/impl/xmr/) now build behind CI on both build legs. Current master CI is green across the required per-coin gates and the coin matrix (DASH / LTC / BCH / DGB / DOGE); the RandomX-dependent XMR checks run CI-gated in light mode, and the CodeQL security scan is a non-gating job.

Provenance

c2pool builds on ideas from p2pool but is an independent codebase. No outside party is represented as endorsing, maintaining, or being involved in c2pool.

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Credits

c2pool is an independent C++ implementation of the P2Pool sharechain concept originally created by Forrest Voight (forrestv, https://github.com/forrestv/p2pool).

Development is supported by Anthropic's Claude for Open Source program (2026). The design, the consensus rules, and responsibility for every byte shipped remain with the maintainers.

First merged-mined DOGE block: #6135703 (2026-03-23) — decentralized LTC+DOGE merged mining via P2Pool V36, cross-validated with c2pool on shared share chain

First daemonless DOGE block: (2026-03-27) — DOGE block accepted on testnet4alpha via embedded SPV P2P, no dogecoind RPC needed

Daemonless DASH chain state at the live tip (2026-07-29) — an embedded DASH node started from an empty data dir reached mainnet tip #2513008 in about four minutes with no dashd in the path: 16 MB of headers, 57 tip advances, and the full masternode set (8,620 deltas over 59 mnlistdiff messages) acquired entirely over coin P2P rather than from protx list. Chain-state acquisition only — this is not a block found daemonlessly on DASH.

First V36 Twin Block: LTC #3085349 + DOGE #6154761 (2026-04-05) — simultaneous LTC+DOGE block found by v36-signalling nodes running p2pool v36 producing V35 shares with desired_version=36; detected and displayed by c2pool's embedded block scanner

Sharechain Transparency Explorer (2026-04-07) — defragmenter-style sharechain visualization with interactive PPLNS treemaps, animated hover effects, per-miner LTC+DOGE payout breakdown, V36 upgrade pressure for V35 miners

Recent Bitcoin Block Mined by P2pool (2026-06-27 05:34:44 UTC) BTC #955609

Recent Bitcoin Block Mined by P2pool (2025-03-07 06:08:22 UTC) BTC #886688

First DASH block, c2pool (2026-07-20 01:15:15 UTC) DASH #2507753 — a solo X11 block. The DIP4 coinbase pays the masternode the network requires at that height, and dashd accepted it. The payee is checked against the template before the block is broadcast; work built on a stale template is discarded, not mined.

DASH block at a full-payment height (2026-07-20 23:25:32 UTC) DASH #2508254 — six transactions, three consensus-mandated payments in the coinbase. The full payee set was assembled and verified against the template before submission, and dashd accepted the block. The demanding case takes the same path as the trivial one.

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Tested platforms

OS	Version	Compiler	Boost	Arch	Status
Ubuntu	24.04.4 LTS	GCC 13.3	1.90 (Conan)	x86_64	Working
macOS	26.3.1 (Tahoe)	Apple Clang 21.0	1.90 (Homebrew)	x86_64 Intel	Working
macOS	26.3.1 (Tahoe)	Apple Clang 21.0	1.90 (Homebrew)	arm64 (M-series)	Working
Windows	11 (26100)	MSVC 2022	1.90 (Conan)	x86_64	Working

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Download

Pre-built binaries are available on the Releases page. The current release line is v0.2.x (V36). Packages are built per parent chain and named c2pool-<coin>-<version>-<platform> (ltc, btc, dgb, dash, bch, bip110 — the coin matrix in .github/workflows/release.yml).

Platform	Package	Notes
Linux x86_64	.tar.gz	Extract and run ./start.sh
macOS (universal)	.dmg or .zip	Single universal arm64 + x86_64 build (lipo-merged); bundled dylibs, no Homebrew needed
Windows x86_64	.zip or setup.exe	Installer bundles VC++ Runtime + firewall rules

Verify downloads

Each release includes a SHA256SUMS file. Verify after downloading:

# Linux / macOS
sha256sum -c SHA256SUMS

# Windows (PowerShell)
Get-FileHash c2pool-*-setup.exe -Algorithm SHA256
# Compare with the hash in SHA256SUMS

Reproducible builds

All release binaries are built from the tagged git commit. To verify a binary matches the source:

1. Check the git tag: git log v0.2.0 --oneline -1
2. Build from that tag following the platform-specific guide
3. Compare the SHA256 of your binary with the release SHA256SUMS

Exact binary reproducibility depends on compiler version and build environment. The SHA256SUMS file in each release documents the official build output.

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Quick start

Linux (Ubuntu 24.04)

sudo apt-get install -y g++ cmake make libleveldb-dev libsecp256k1-dev python3-pip
pip install "conan>=2.0,<3.0" --break-system-packages
export PATH="$PATH:$HOME/.local/bin"   # so `conan` is on PATH (add to ~/.bashrc to persist)
conan profile detect --force

git clone https://github.com/frstrtr/c2pool.git
cd c2pool && mkdir build && cd build
conan install .. --build=missing --output-folder=. --settings=build_type=Debug
cmake .. --preset conan-debug
cmake --build . --target c2pool -j$(nproc)
./src/c2pool/c2pool

Linux (Ubuntu 26.04 LTS) — theoretical: CI builds on 24.04, so the 26.04 path below is documented from known toolchain deltas, not yet exercised in the CI matrix. Report any gotcha via an issue.

The 24.04 steps above apply unchanged; the build is Conan-managed, so it is largely toolchain-version agnostic. Expect only these deltas on 26.04:

• Newer default compiler. 26.04 LTS ships a newer default GCC (15.x) / libstdc++. No action needed — conan profile detect --force picks up the system toolchain, and conan install --build=missing builds the C++ dependencies (Boost 1.90, etc.) against it. If the newer compiler turns a dependency warning into an error, --build=missing already rebuilds that dependency from source with your toolchain.
• Externally-managed pip (PEP 668). As on 24.04, install Conan with pip install "conan>=2.0,<3.0" --break-system-packages, or prefer an isolated pipx install "conan>=2.0,<3.0" (sudo apt-get install -y pipx) so the tool does not touch the system Python. (Conan is c2pool's C++ dependency manager — a pip-distributed tool — and is unrelated to any Python component of a pool.)
• apt package names are unchanged: g++ cmake make libleveldb-dev libsecp256k1-dev python3-pip.

Everything else — conan install → cmake --preset conan-debug → cmake --build — is identical to 24.04.

macOS (Intel & Apple Silicon)

xcode-select --install
brew install cmake boost leveldb secp256k1 nlohmann-json yaml-cpp

git clone https://github.com/frstrtr/c2pool.git
cd c2pool && mkdir build && cd build
cmake .. -DCMAKE_BUILD_TYPE=Release
cmake --build . --target c2pool -j$(sysctl -n hw.ncpu)
./src/c2pool/c2pool

Windows (setup.exe or build from source)

Download c2pool-ltc-VERSION-windows-x86_64-setup.exe from Releases and run the installer. Or build from source — see doc/build-windows.md.

That's it. No litecoind, no dogecoind, no config file. The node starts in integrated P2P pool mode with embedded LTC and DOGE SPV nodes, connects to p2pool sharechain peers via hardcoded bootstrap hosts, and waits for shares before opening stratum to miners.

Miners connect to stratum and set their LTC payout address as the username (p2pool convention). No --address flag needed.

Full step-by-step guides: Linux | macOS | Windows

Common operator questions (merged coins, payouts, dashboard): docs/FAQ.md

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Operating modes

The Operating modes, Defaults, Peer discovery, Merged mining, Ports and Configuration reference sections below describe the LTC binary (c2pool-ltc, dev alias c2pool, src/c2pool/main_ltc.cpp). The other per-coin binaries have their own, smaller flag surfaces — see Per-binary launch reference.

c2pool has four operating modes. The default is a full P2P pool — no flags required.

Mode	CLI flag	P2P sharechain	Coinbase payouts	Use case
Integrated	(default)	yes	PPLNS from sharechain	Decentralized pool node
Solo	--solo	no	Proportional by miner hashrate	Private pool for own ASICs
Custodial	--custodial	no	100% to --address	Hosted pool, off-chain accounting
Sharechain	--sharechain	yes	(no mining)	P2P relay node only

Legacy --standalone mode (minimal stratum + RPC daemon, no embedded SPV) is available for backwards compatibility.

DASH daemonless masternode-set checkpoint — trust anchor

If you run DASH without a dashd arm (a bare --run is daemonless by default), you are trusting the c2pool release build for one specific piece of data. This section says exactly which, and why.

To build a DASH block, c2pool must know which masternode is next in the DIP-3 payment queue. Paying the wrong one produces a coinbase the network rejects (bad-cb-payee) — a mined block thrown away. Ranking the queue needs each masternode's scriptPayout and nLastPaidHeight, and neither is available from the DASH P2P network: the Simplified MN List (mnlistdiff) omits both, and neither is committed in merkleRootMNList, so there is no header commitment to check them against.

So c2pool ships a release-pinned masternode set — a trust anchor of the same class as Bitcoin Core's assumeutxo — and replays blocks forward from it to the current tip.

What the node verifies for itself, with no trust:

• chain position — the anchor names a block hash, and is rejected unless c2pool's own X11-PoW + DGW-validated header chain holds exactly that hash at exactly that height;
• integrity — a SHA-256 digest over the anchor's contents (an integrity check on the file, not a signature: whoever can change the source can recompute the digest — it catches accidents, not malice);
• forward consistency — every block replayed from the anchor re-derives the projected payee and compares it against that block's real coinbase, so a wrong anchor is falsified within a few blocks.

What you are trusting: the membership and payout state of the masternode set at the anchor height. Nothing available to the node can prove it.

A fully trustless alternative exists — replaying every block from DIP-3 activation (~1.5M blocks) — and is planned as a later opt-in verify-mode. It is not implemented today.

Fail-closed by design. If the anchor is missing, corrupt, for the wrong network, in the wrong chain position, further behind the tip than --embedded-mn-bridge-max (default 20000 blocks, ≈34 days), or contradicted by a replayed block, c2pool logs the refusal at ERROR and refuses to serve embedded DASH templates. It falls back to a configured dashd, or serves nothing. It never guesses a masternode payee.

Running DASH with a dashd RPC configured does not use the anchor at all — protx list registered true is authoritative and is used instead.

Both the anchor and the RPC seed carry the registered masternode set, not the valid one: protx list valid filters PoSe-banned masternodes out entirely, which makes "banned" and "does not exist" the same observation. Because the replay's only insertion path is ProRegTx, a ProUpServTx that later revives such a masternode would have no entry to revive, and it could never re-enter the DIP-3 payment queue — leaving every later payee projection one queue slot ahead of the chain's. Carrying banned masternodes as present but ineligible (eligibility is derived from poseBanHeight) keeps the revive path working.

Details, provenance of the shipped anchor, and the release-time re-pinning procedure: src/impl/dash/coin/checkpoints/README.md.

Startup examples

# Default: full P2P pool, embedded SPV, wait for peers
./c2pool

# Same, with explicit address for node-owner fee
./c2pool --address YOUR_LTC_ADDRESS --fee 1

# Solo pool for own miners (no sharechain, proportional payouts)
./c2pool --solo

# Custodial pool (all coinbase to operator, stratum for accounting)
./c2pool --custodial --address YOUR_LTC_ADDRESS

# With external LTC daemon instead of embedded SPV
./c2pool --no-embedded-ltc \
  --coind-address 127.0.0.1 --coind-rpc-port 9332 \
  --rpcuser user --rpcpassword pass

# Testnet
./c2pool --testnet

# With config file
./c2pool --config config/c2pool_mainnet.yaml

# Full option reference
./c2pool --help

Feature matrix

Feature	Integrated	Solo	Custodial	Sharechain
Embedded LTC SPV	on	on	on	--
Embedded DOGE SPV	on	on	on	--
Stratum server	yes	yes	yes	--
VARDIFF	yes	yes	yes	--
P2P share exchange	yes	--	--	yes
PPLNS payouts	yes	--	--	--
Proportional payouts	--	yes	--	--
Single-address coinbase	--	--	yes	--
Merged mining (DOGE etc.)	yes	yes	yes	--
Web dashboard + REST API	yes	yes	yes	--
Per-worker accounting	yes	yes	yes	--
--address required	no	no	yes	no
--fee supported	yes	yes	--	--
Redistribute modes	yes	--	--	--
ShareTracker / LevelDB	yes	--	--	yes
Think loop / monitoring	yes	--	--	--

Payout model by mode

Mode	Who gets paid	How amounts are calculated
Integrated	All miners in PPLNS window	Share weight from sharechain (decentralized consensus)
Solo	Connected stratum miners	Proportional to real-time hashrate from RateMonitor
Custodial	Node operator only	100% of block reward to --address; miners tracked in /stratum_stats

In integrated and solo modes, miners set their payout address as their stratum username (e.g., LcAddress.worker1). The address appears directly in coinbase outputs. --address is optional — it serves as the node operator's fee destination and fallback when no miners are connected.

In custodial mode, miner stratum usernames are used for accounting only and never appear in coinbase outputs. The backoffice polls /stratum_stats for per-worker hashrate, accepted shares, and connection time.

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Defaults

Running c2pool with no arguments is equivalent to:

--integrated --embedded-ltc --embedded-doge --wait-for-peers
--header-checkpoint 3088000:4a7fc8d4...
--doge-header-checkpoint 6160000:51efd04d...

Setting	Default	Override
Operating mode	Integrated P2P pool	--solo, --custodial, --sharechain, --standalone
LTC backend	Embedded SPV (DNS seeds)	--no-embedded-ltc (requires RPC daemon)
DOGE backend	Embedded SPV	--no-embedded-doge (disables merged mining)
LTC bootstrap	Block 3,088,000	--header-checkpoint HEIGHT:HASH
DOGE bootstrap	Block 6,160,000	--doge-header-checkpoint HEIGHT:HASH
Startup mode	Wait for peers (persist=true)	--genesis or --startup-mode auto
Coin daemon	Not required	--coind-address / --coind-rpc-port
--address	Optional (miners use stratum username)	Required only for --custodial
--fee	0%	-f 1 (1% to --address)
Stratum port	9327	-w PORT
P2P port	9326	--p2pool-port PORT
Web port	8080	--web-port PORT
Data directory	~/.c2pool (%APPDATA%\c2pool on Windows)	--data-dir PATH

Running two instances on one host? Give each its own --data-dir. All per-instance on-disk state — the sharechain LevelDB, address store, whitelist, logs, ratchet, and found-blocks db — is rooted there, so co-located instances never contend the same LevelDB LOCK. Leaving it unset keeps the historical ~/.c2pool path, byte-for-byte unchanged.

Testnet overrides

On --testnet, mainnet SPV checkpoints are automatically cleared (testnet uses a different chain). Ports shift to testnet defaults (P2P 19326, stratum 19327).

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Peer discovery and sharechain bootstrap

The sharechain P2P layer discovers peers from multiple sources:

Source	Config	Priority
CLI seed nodes	-n HOST:PORT (repeatable)	Highest
YAML config	seed_nodes: list	Appended to CLI
~/.c2pool/ltc/pool.yaml	bootstrap_addrs: (auto-generated, persists learned peers)	Medium
Hardcoded bootstrap hosts	ml.toom.im, usa.p2p-spb.xyz, + 9 IPs	Fallback

With startup_mode: wait (default), the node waits until peers deliver shares before opening stratum. This matches p2pool's PERSIST=True behavior.

Startup mode	CLI flag	Behavior
wait (default)	--wait-for-peers	Wait for peers to deliver shares, then mine
genesis	--genesis	Create first share immediately (new chain)
auto	--startup-mode auto	Wait 60s for peers, then genesis

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Merged mining

LTC and DOGE have built-in embedded SPV nodes (enabled by default). Other chains need their daemon running externally.

Coin	chain_id	Backend	--merged example
DOGE	98	Embedded SPV	auto-configured
PEP	63	External	PEP:63:127.0.0.1:29377:user:pass
BELLS	16	External	BELLS:16:127.0.0.1:19918:user:pass
LKY	8211	External	LKY:8211:127.0.0.1:9916:user:pass
JKC	8224	External	JKC:8224:127.0.0.1:9770:user:pass
SHIC	74	External	SHIC:74:127.0.0.1:33863:user:pass
DINGO	98	External	Cannot run with DOGE (same chain_id)

DOGE merged mining activates automatically when --embedded-doge is on (default). External daemons use createauxblock/submitauxblock RPC.

DigiByte Scrypt is its own parent chain with its own binary and sharechain: c2pool-dgb (src/c2pool/main_dgb.cpp, sharechain port 5024). It is not selected through the LTC binary — --net digibyte on c2pool-ltc is the LTC binary's legacy chain selector (--net CHAIN, main_ltc.cpp usage text), not the DGB pool. See c2pool-dgb below.

---

Ports

Port	Purpose
9326	P2Pool sharechain (peer-to-peer)
9327	Stratum mining
8080	Web dashboard + REST API

---

Configuration

Settings file (TOML) — all binaries

Every node binary resolves its launch configuration in three layers (src/core/settings_cli.hpp): compiled defaults (L0) < settings file (L1) < command line (L2). The CLI always wins, even over a money-class key that the file has acknowledged. The catalog of every key and its per-binary CLI spelling is src/core/param_catalog.inc.

Flag	Binaries	Behaviour
--settings PATH	ltc, dash, btc, dgb, bch	Explicit settings-file path. The file must exist — a typo is fatal (exit 78), it never falls through silently. Omitted: <data-dir>/c2pool.toml is loaded if present, else the run is pure compiled+CLI. (settings_cli.hpp resolve_settings_path)
--dump-resolved-config	ltc, dash, btc, dgb, bch	Print the fully resolved config with the source of every key (compiled / file / CLI) between === RESOLVED CONFIG BEGIN === / END markers, then exit 0 without starting the node. Works with no coin endpoint configured.
--ack-money-settings	ltc, dash, btc, dgb, bch	Compute and print the money-ack hash for the resolved settings file, then exit. Requires a settings file (--settings PATH or the data-dir default); exit 78 otherwise.
--data-dir PATH	ltc, dash, btc, dgb, bch	Root all per-instance state (sharechain LevelDB, addr store, logs, …) under PATH (default ~/.c2pool). Handled before the settings probe, so the default c2pool.toml is looked up under the final data dir. Requires a non-empty, non-flag argument (exit 1 otherwise).

Money gate. A settings file can never silently arm a money-class key (MONEY_* rows in the catalog: fees, donation, payout addresses, network identity, embedded.null_arm, …). A file that sets such a key without a matching [gate].money_ack_hash is refused and the node exits 78 (EX_CONFIG) before anything starts (src/core/settings_file.hpp). Run --ack-money-settings to obtain the hash for the file as it stands, put it in [gate].money_ack_hash, and the file is accepted; any later edit to a money key invalidates the hash.

c2pool-bip110 does not take --settings / --data-dir / --dump-resolved-config (no BIN_BIP110 alias for those rows in param_catalog.inc); its money defaults are seeded from the catalog and overridden only by CLI flags (main_bip110.cpp main()).

Legacy YAML config (--config, LTC only, deprecated)

--config FILE loads a YAML overlay on the LTC binary only. It is catalogued as meta.config_yaml — "DEPRECATED legacy YAML config overlay" (param_catalog.inc) — and is kept this release for byte-identical behaviour of existing YAML deployments. If both a --config YAML and a TOML settings file resolve, the TOML is skipped with a loud warning and the YAML wins for this release (main_ltc.cpp, M0b wiring block). Migrate to the TOML settings file; the YAML path will be removed.

# Legacy (LTC only, deprecated)
./c2pool --config config/c2pool_mainnet.yaml

See config/c2pool_mainnet.yaml (mainnet) and config/c2pool_testnet.yaml (testnet) for the legacy YAML key set.

Configuration reference (LTC binary)

CLI flag	YAML key	Default	Description
--integrated	integrated	true	Full P2P pool mode
--solo	solo	false	Solo pool (no sharechain)
--custodial	custodial	false	Custodial pool (single-address coinbase)
--sharechain	sharechain	false	P2P node only (no mining)
--standalone	--	false	Legacy solo (RPC daemon, no embedded SPV)
--embedded-ltc	embedded_ltc	true	Embedded LTC SPV node
--no-embedded-ltc			Disable embedded LTC, use RPC daemon
--embedded-doge	embedded_doge	true	Embedded DOGE SPV for merged mining
--no-embedded-doge			Disable embedded DOGE
--net	--	litecoin	LTC-binary chain selector (--net CHAIN; alias --blockchain). Not the way to run DGB/BTC/BCH/DASH pools — those are separate binaries
--testnet	testnet	false	Enable testnet mode
--settings FILE	--	<data-dir>/c2pool.toml	TOML settings file (all binaries; see above)
--dump-resolved-config	--	--	Print resolved config with sources, exit 0
--ack-money-settings	--	--	Print the money-ack hash for the settings file, exit
--config FILE	--	--	Deprecated legacy YAML overlay (LTC only); takes precedence over TOML this release
--address	solo_address	--	Node operator payout address (optional)
--give-author	donation_percentage	0.1	Developer fee % (p2pool default: 0.5%)
-f / --fee	node_owner_fee	0	Node owner fee %
--node-owner-address	node_owner_address	--	Node owner payout address
--redistribute	redistribute	pplns	Mode: pplns/fee/boost/donate
-n HOST:PORT	seed_nodes	--	Sharechain seed peer (repeatable)
--startup-mode	startup_mode	wait	Bootstrap: wait, genesis, auto
--genesis			Shortcut for --startup-mode genesis
--wait-for-peers			Shortcut for --startup-mode wait
--header-checkpoint	header_checkpoint	mainnet default	LTC SPV starting point (HEIGHT:HASH)
--doge-header-checkpoint	doge_header_checkpoint	mainnet default	DOGE SPV starting point
--p2pool-port	port	9326	P2P sharechain port
-w / --worker-port	stratum_port	9327	Stratum mining port
--web-port	web_port	8080	HTTP API / dashboard port
--http-host	http_host	0.0.0.0	HTTP bind address
--coind-address	ltc_rpc_host	127.0.0.1	Coin daemon RPC host
--coind-rpc-port	ltc_rpc_port	auto	Coin daemon RPC port
--rpcuser	ltc_rpc_user	--	RPC username
--rpcpassword	ltc_rpc_password	--	RPC password
--max-conns	--	8	Target outbound P2P peers
--stratum-min-diff	min_difficulty	0.0005	Vardiff floor
--stratum-max-diff	max_difficulty	65536	Vardiff ceiling
--stratum-target-time	target_time	3.0	Seconds between pseudoshares
--no-vardiff	vardiff_enabled	true	Disable auto-difficulty
--max-coinbase-outputs	max_coinbase_outputs	4000	Max coinbase outputs
--network-id	network_id	0	Private chain identifier (hex)
--log-level	log_level	trace	trace/debug/info/warning/error
--log-file	log_file	debug.log	Log filename
--log-rotation-mb	log_rotation_size_mb	100	Log rotation threshold (MB)
--log-max-mb	log_max_total_mb	1000	Total size cap across all rotated log files (MB)
--p2p-max-peers	p2p_max_peers	30	Max total P2P peers
--ban-duration	ban_duration	300	P2P ban duration (seconds)
--rss-limit-mb	rss_limit_mb	4000	RSS memory abort limit (MB)
--cors-origin	cors_origin	--	CORS Allow-Origin header
--payout-window	payout_window_seconds	86400	PPLNS window (seconds)
--storage-save-interval	storage_save_interval	300	Sharechain save interval
--dashboard-dir	dashboard_dir	web-static	Static dashboard directory
--analytics-id	analytics_id	--	Google Analytics measurement ID (e.g. G-XXXXXXXXXX); injected into dashboard HTML </head>
--	address_explorer_prefix	Blockchair	Custom address explorer URL prefix
--	block_explorer_prefix	Blockchair	Custom block explorer URL prefix
--	tx_explorer_prefix	Blockchair	Custom tx explorer URL prefix
--	explorer	false	Enable lite block explorer (stores recent blocks + REST API)
--	explorer_url	--	Explorer URL injected into dashboard nav (e.g. http://localhost:9090)
--	explorer_depth_ltc	288	LTC blocks to keep in explorer store
--	explorer_depth_doge	1440	DOGE blocks to keep in explorer store
--coinbase-text	coinbase_text	see below	Custom coinbase scriptSig text
--message-blob-hex	--	--	V36 authority message blob
--doge-testnet4alpha	doge_testnet4alpha	false	Use DOGE testnet4alpha

---

Per-binary launch reference

Each parent chain ships as its own binary with its own hand-written argv parser. The tables below are transcribed from those parsers on master — the --help text of some binaries lags the parser, so the parser is the source of truth cited here (src/c2pool/main_<coin>.cpp; canonical key names in src/core/param_catalog.inc). The --settings / --dump-resolved-config / --ack-money-settings / --data-dir control-plane flags are described once under Settings file (TOML) and only listed here.

Common conventions:

• [HOST:]PORT — a bare port binds 0.0.0.0; HOST:PORT binds one interface.
• Stratum and the web dashboard are off unless bound on btc, dgb, bch and dash (--stratum / --http; DASH's dashboard is the exception and is on at 8080 by default). bip110 binds Stratum on 9336 by default.
• Unknown flags: dash, btc, dgb, bch reject them with a non-zero exit; bip110 silently ignores them (its parse loop has no trailing else).
• Coin-daemon RPC credentials are never taken on argv: every --coin-rpc-auth / --rpc-conf points at a bitcoin.conf-style file.

Default ports by binary

Binary	Sharechain P2P	Stratum	Web dashboard	Coin P2P (embedded)
c2pool-ltc	9326 (--p2pool-port)	9327 (-w)	8080 (--web-port)	embedded LTC + DOGE SPV (DNS seeds)
c2pool-btc	9333 (--sharechain-port)	off (--stratum)	off (--http)	8333 (--coin-p2p-discover)
c2pool-dgb	5024 (--sharechain-port)	off (--stratum)	off (--http)	12024 (--coin-p2p-discover / --coin-daemon)
c2pool-bch	9349 (fixed)	off (--stratum)	off (--http)	8333 (--peer, or seed ladder when --peer port is 0)
c2pool-dash	8999 mainnet / 18999 testnet (--listen)	off (--stratum)	8080 (--web-port; 0 disables)	9999 (--coin-p2p-connect / --coin-p2p-discover)
c2pool-bip110	9337 (--bip110-sharechain to enable)	9336 (--no-stratum to disable)	off (--http)	8333 (--peer / --coin-p2p-discover)

Sources: src/impl/{btc,dgb,bch,dash}/config_pool.hpp P2P_PORT; src/impl/bip110/params.hpp SHARECHAIN_P2P_PORT / SHARECHAIN_WORKER_PORT / COIN_P2P_PORT; each main_<coin>.cpp local-variable defaults.

c2pool-dash — Dash (X11)

Source: src/c2pool/main_dash.cpp — print_banner() (usage text) and the main() parse loop. Unknown argument → unknown argument: …, exit 1.

# Daemonless public pool (the dash.voidbind.com posture, no dashd on the host)
./c2pool-dash --run --data-dir /var/lib/c2pool/dash \
  --coin-p2p-discover --coin-p2p-peers 8 \
  --listen 0.0.0.0:8999 --addnode <sharechain-peer>:8999 \
  --stratum 0.0.0.0:7903 --web-host 127.0.0.1 --web-port 8082 \
  --dashboard-dir /opt/c2pool/web-static \
  --node-owner-address <your-DASH-address>

# dashd-attached (reward-safe fallback arm kept; creds read from dash.conf)
./c2pool-dash --run --coin-rpc 127.0.0.1:9998 --coin-rpc-auth ~/.dashcore/dash.conf \
  --stratum 3335

A bare --run with no --coin-rpc is the daemonless posture: every embedded serving lever below defaults ON ("ALL embedded serving levers default ON when NO dashd arm is given", banner text; resolver src/impl/dash/coin/good_citizen_defaults.hpp). With --coin-rpc given, the node is dashd-attached and the --embedded-* levers default OFF unless named. Only the daemonless trust anchor applies to a daemonless node — see DASH daemonless masternode-set checkpoint.

Modes and control plane

Flag	Meaning
--run	Stand up the node (sharechain peer, coin feed, Stratum, web). Without it the binary runs the self-test and exits.
--selftest	Accepted explicitly; same as the default path.
--version / --help	Print and exit.
--data-dir PATH, --settings PATH, --dump-resolved-config, --ack-money-settings	Control plane, see Settings file.
--testnet / --regtest	Both set the testnet flag (the parser treats them identically). Sharechain port becomes 18999.
--mine-block [--payout-pubkey-hash HEX] [--max-nonce N]	One-shot CPU miner harness.
--submit-block HEX / --submit-block-file PATH	Drive one real submitblock through the dashd arm, then exit.
--replay-utxo-db PATH [--replay-utxo-hash] [--replay-utxo-expect HEX]	Standalone UTXO-fold utility; runs and exits, never serves.
--dump-mn-checkpoint H FILE	Write the self-derived masternode set at height H as a checkpoint .inc; two arguments.

Coin daemon arm (optional)

Flag	Default	Meaning
--coin-rpc H:P (alias --coin-daemon)	none = daemonless	dashd RPC endpoint. Endpoint only, no secret.
--coin-rpc-auth PATH	~/.dashcore/dash.conf	dash.conf with rpcuser/rpcpassword.
--coin-zmq-hashblock tcp://H:P	off	Subscribe to dashd ZMQ hashblock for instant tip refresh on the fallback arm (needs zmqpubhashblock in dashd).
--embedded-oracle-shadow, --oracle-graduation-blocks N (5000), --oracle-class-coverage K (20)	off	Observe-only per-block dashd cross-check + graduation ledger. Needs the RPC arm.
--embedded-shadow-compare	off	Observe-only served-template vs getblocktemplate diff on a worker thread. No-op without dashd.
--embedded-no-dashd-mn-seed [--embedded-fold-only-proof]	off	Cut the protx list payee seed while keeping dashd for observation (cut rehearsal); the second flag also leaves the checkpoint bridge unarmed.

Sharechain and coin P2P

Flag	Default	Meaning
--listen [HOST:]PORT	0.0.0.0:8999	Sharechain (pool P2P) bind.
--addnode H:P (repeatable)	—	Persistent outbound sharechain peers.
--connect H:P (repeatable)	—	Connect-only sharechain peers.
--no-p2p-relay	off	Suppress the embedded won-block P2P relay (isolates the RPC submit arm).
--coin-p2p-connect H:P (repeatable)	—	Pin explicit DASH coin-network peers (port 9999).
--coin-p2p-discover	off	Seed-based (dnsseed.dash.org + fixed), scored, group-diverse coin-peer discovery — the network-standalone arm. Pinned peers are kept alongside.
--coin-p2p-peers N	8 (cap 16)	Concurrent coin-network peers held. An evidence knob: qfcommit/clsig are announced once, so more peers = lower miss probability.
--coin-p2p-magic HEX	mainnet bf0c6bbd	Wire-magic override (testnet cee2caff, regtest fcc1b7dc).
--embedded-fresh-datum-race[=false], --embedded-fresh-datum-race-k N (2)	off (fresh_datum_race.hpp: static bool f = false; the catalog help string says "default ON" — the code is authoritative)	Race the freshest getmnlistd to K distinct netgroups; fold the first self-checked reply.
--embedded-getmnlistd-tracker[=false]	off (getmnlistd_tracker.hpp: static bool f = false; same catalog/code mismatch)	Fixed 10 s per-slot re-ask tracker for the MnListDiff class.
--embedded-asn-diversity[=false]	off	Require the racing set to span ≥2 ASNs.
--embedded-peer-latency-score[=false]	off	Latency tie-breaker inside the eligible peer set.
--embedded-proactive-rotate	off	Low-rate proactive coin-peer rotation (default is stall-only).

Embedded serving levers (all daemonless-default ON, =false opts out; dashd-attached default OFF)

Flag	Meaning
--embedded-mainnet[=false]	The arm gate: serve embedded templates on mainnet and arm the coin-state feed. =false on a mainnet node serves only the dashd fallback.
--embedded-utxo[=false]	Embedded UTXO / fee lane.
--embedded-null-arm[=false]	Optimistic null quorum commitment at fresh window-open slots, freshness-gated (#127).
--embedded-superblock[=false]	Daemonless superblock payee sourcing via govsync.
--embedded-govsync	Observe-only governance store (inv 17/18 pull). Does not arm serving by itself.
--embedded-serve-mempool-txs[=false]	Serve fee-carrying templates from the embedded mempool.
--embedded-tx-serve-own-set[=false]	Serve-time self-validation referee.
--embedded-mempool-ingest[=false]	Coin-P2P MSG_TX pull (fills the mempool).
--embedded-ingest-isdlock[=false]	MSG_ISDLOCK feed (InstantSend conflict locks, BLS-gated).
--embedded-ingest-dstx[=false]	CoinJoin DSTX lane.
--embedded-include-mn-special-txs[=false]	DIP special-tx superset (types 1–4).
--embedded-accrue-asset-locks[=false] / --embedded-accrue-asset-unlocks[=false]	Type-8 / type-9 asset-lock/unlock fold.
--embedded-utxo-immature-serve-empty	Serve coinbase-only until the UTXO view is mature.
--embedded-creditpool-publish-at-serve-tip	Publish the derived credit pool at the serve tip (money path, default OFF).
--embedded-mined-commitment-index	Arm the mined-commitment store on live tips.
--embedded-mn-bridge-max N	Max blocks the pinned masternode anchor may lag the tip before the bridge refuses it as stale (default 20000, mn_checkpoint_lane.hpp).
--embedded-mn-bridge-no-cursor	Replay the whole window from the anchor on every start instead of resuming the saved cursor.
--embedded-fold-live PATH + --embedded-fold-live-expect HASH, --embedded-fold-checkscripts	Wire a full-history UTXO fold store as the live input-pricing view (store hash must match); consensus-exact input-script check.
--embedded-utxo-fold-fees DBPATH + --embedded-utxo-fold-expect HEX	Graduated fold fee pricing; both required together.
--bestcl-policy freshness|consensus-exact	How the bestCL gate decides (default freshness).
--serve-staleness-sentinel[=off]	Report-only served-height staleness detector, ON by default; =off/=0/=false disables.
--serve-gate-state-file PATH	Cross-restart serve-gate accounting (soak convenience).
--regtest-force-won-block	Regtest-only: drive one won block through the dual-path dispatch.

Transactions, replay, checkpoints

Flag	Meaning
--embedded-tx-inject, --embedded-tx-inject-hex FILE	Opt-in miner/user tx injection (#157), default OFF.
--pin-local-tx-hex FILE, --pin-splice-xcheck-arm, --pin-splice-block-budget	Pin a zero-fee self-mined tx (e.g. donation consolidation) into served templates; splice policy knobs default OFF.
--replay-bulk, --replay-bulk-capture DIR, --replay-bulk-start H	Full-history bulk block-fetch lane from DIP3 (1028160); capture caches bodies.
--replay-fold-prestate FILE, --replay-fold-quorums, --replay-fold-qsnapshot FILE, --replay-fold-worklists FILE	Anchor-seeded DML fold driven by the bulk lane, with derived quorum member sets.
--replay-mnlist-seed-height H --replay-mnlist-seed-source getmnlistdiff --replay-mnlist-seed-file FILE	Optional V20 getmnlistdiff seed instead of deriving from DIP3 (implies --replay-bulk).
--replay-mined-commitment-index	Mined-commitment store fed from replay.

Web, money, misc

Flag	Default	Meaning
--stratum [HOST:]PORT	off	Miner-facing Stratum listener.
--web-port PORT (alias --http-port)	8080	Dashboard + JSON API; 0 disables. If it collides with the Stratum port it moves to stratum+1.
--web-host ADDR	0.0.0.0	Dashboard bind interface.
--dashboard-dir PATH	web-static	Static dashboard root.
--external-ip ADDR (aliases --stratum-advertise, --public-host)	auto-detect	Miner-facing host shown in the dashboard Stratum URL (NAT).
--explorer / --no-explorer	on	Loopback-only /api/explorer surface + raw-block retention.
--give-author PCT (alias --dev-donation)	0.1	Author donation percent.
-f / --fee PCT	0	Node-owner fee percent.
--node-owner-address ADDR	—	Fee destination.
--redistribute pplns|fee|boost|donate	pplns	Unnamed-share redistribution.
--coinbase-text TEXT	/P2Pool-DASH/c2pool/	Coinbase scriptSig text, max 64 bytes (see Coinbase structure).
--message-blob-hex HEX (alias --transition-message)	—	Encrypted authority message blob.

c2pool-btc — Bitcoin (SHA256d)

Source: src/c2pool/main_btc.cpp — print_usage() and the main() parse loop. Unknown argument → unknown arg: … + usage, exit 1. There is no --version flag on this binary. A coin source is mandatory: without --bitcoind or --coin-p2p-discover the binary prints usage and exits 1.

# Daemonless public pool (btc.voidbind.com posture)
./c2pool-btc --data-dir /var/lib/c2pool/btc --coin-p2p-discover \
  --http 127.0.0.1:8083 --stratum 0.0.0.0:9334 \
  --fee 0.1 --node-owner-address <your-BTC-address> --give-author 0

# Against a local bitcoind P2P port, with the submitblock RPC backup
./c2pool-btc --bitcoind 127.0.0.1:8333 --coin-rpc 127.0.0.1:8332 \
  --coin-rpc-auth ~/.bitcoin/bitcoin.conf --stratum 9332

Flag	Default	Meaning
-h / --help		Usage and exit 0.
--data-dir PATH, --settings PATH, --dump-resolved-config, --ack-money-settings		Control plane, see Settings file. --dump-resolved-config runs before the mandatory-coin-source check, so it works with no endpoint.
--testnet / --testnet4 / --regtest	mainnet	Chain selection (testnet4 also sets the testnet flag).
--bitcoind HOST:PORT	—	bitcoind P2P endpoint (8333 / 18333 / 48333 testnet4 / 18443 regtest). Required unless --coin-p2p-discover.
--coin-p2p-discover	off	BTC-isolated scored, group-diverse coin-peer discovery (DNS + fixed + HTTP seeds); streams headers with no bitcoind.
--p2pool HOST:PORT	—	Single BTC p2pool peer; folds into --sharechain-addnode as an exclusive target.
--sharechain-addnode HOST:PORT (repeatable)	—	Explicit sharechain peers. When given, the public seed list is not dialed and the saved addr book is reset.
--sharechain-port P	9333	Sharechain listener port (second instance on one host).
--network-id HEX (≤8 bytes), --prefix HEX	public BTC	Private sharechain identifier / prefix — two independent constants. Setting --network-id alone also suppresses the public seed list.
--stratum [HOST:]PORT	off	Stratum listener.
--http [HOST:]PORT	off	Operator dashboard (web-static relative to the working directory; parser only — not in the --help text).
--coin-rpc HOST:PORT	—	submitblock RPC backup endpoint (no secret on argv).
--coin-rpc-auth PATH	~/.bitcoin/bitcoin.conf	rpcuser/rpcpassword file for the backup. Omit both to run daemonless.
--merged SYMBOL:CHAIN_ID:HOST:PORT:USER:PASS[:P2P_PORT] (repeatable)	—	Embedded merged-mined aux chain (NMC under BTC).
-f / --fee PCT	0	Node-owner fee as a committed payout-identity substitution (not a separate output). Requires --node-owner-address.
--node-owner-address ADDR	—	Fee destination (P2PKH/P2SH/P2WPKH). Undecodable → fee disabled.
--give-author PCT (alias --dev-donation)	compiled-in donation_u16 = 50 (the usage text labels it 0.5%)	Donation amount only; 0 allowed (dust-marker output still emitted). The donation script is never changed.

c2pool-dgb — DigiByte (Scrypt)

Source: src/c2pool/main_dgb.cpp — print_banner() and the main() parse loop. Unknown argument → unknown argument: …, exit 1. Mainnet only: there is no --testnet flag and make_coin_params(/*testnet=*/false) is hardwired; a settings file that sets network.testnet is refused. The DGB parser has no --fee / --give-author (the catalog's money.give_author_pct and money.node_owner_fee_pct rows exclude DGB); operator payout goes through --redistribute + --node-owner-address.

# Daemonless public pool (dgb.voidbind.com posture)
./c2pool-dgb --run --coin-p2p-discover --data-dir /var/lib/c2pool/dgb \
  --http 127.0.0.1:8084 --stratum 0.0.0.0:9434 \
  --sharechain-port 5024 --sharechain-addnode 92.53.224.27:5024

Flag	Default	Meaning
--version / --help		Print and exit.
--data-dir PATH, --settings PATH, --dump-resolved-config, --ack-money-settings		Control plane, see Settings file.
--run		Stand up the run-loop (io_context + sharechain peer + Stratum). Without it (or with --selftest) the binary runs the self-test and exits.
--stratum [HOST:]PORT	off	Stratum listener.
--http [HOST:]PORT	off	Dashboard + stats persistence (web-static relative to the working directory).
--sharechain-port P	5024	Sharechain listener port.
--sharechain-addnode HOST:PORT (repeatable)	public defaults	Pin sharechain peers; suppresses the default bootstrap list. 92.53.224.27:5024 is the live public DGB sharechain seed named in the source.
--coin-p2p-discover	off	DGB-isolated scored, diverse coin-peer discovery — daemonless.
--coin-daemon HOST:PORT	—	Explicit embedded coin-P2P producer target (a digibyted P2P port).
--coin-magic HEX, --coin-genesis HASH	mainnet	Wire-magic / genesis overrides (regtest).
--coin-rpc HOST:PORT, --coin-rpc-auth PATH	—	External digibyted submitblock arm; creds stay in digibyte.conf.
--regtest, --regtest-force-won-share	off	Regtest marker; forced won share is refused unless --regtest and --coin-daemon are both given.
--no-p2p-relay	off	Suppress the embedded won-block relay (isolates the RPC arm).
--dev-relax-algo-softforks	off	Dev-only: relax the algo-softfork readiness gate for an isolated tuned testnet; ignored on mainnet.
--redistribute SPEC	pplns	pplns|fee|boost|donate or hybrid boost:70,donate:20.
--node-owner-address ADDR	—	Operator payout identity for the fee arm.
--merged SYMBOL:CHAIN_ID[:HOST:PORT:USER:PASS[:P2P_PORT]] (repeatable)	—	Embedded DOGE aux backend (-DAUX_DOGE build; DOGE chain_id 98, P2P 22556).
--doge-p2p-address HOST, --doge-p2p-port PORT, --embedded-doge	—	DOGE peer overrides; --embedded-doge forces the embedded path.
--embedded-serve-mempool-txs[=true|=false]	posture default	Arm / opt out of the embedded UTXO fee-proof lane. CLI wins over the settings file.

c2pool-bch — Bitcoin Cash (SHA256d)

Source: src/c2pool/main_bch.cpp — print_banner() and the main() parse loop. Unknown argument → unknown argument: …, exit 1. The pool mode is --pool; the other modes are harnesses.

# Daemonless public pool (bch.voidbind.com posture): --peer with port 0 means
# "no explicit BCHN peer" and turns on the DNS/fixed/HTTP seed ladder
./c2pool-bch --pool --peer 0.0.0.0:0 --data-dir /var/lib/c2pool/bch \
  --http 127.0.0.1:8085 --stratum 0.0.0.0:9534 \
  --sharechain-addnode 92.53.224.27:9349

Flag	Default	Meaning
--version / --help		Print and exit (help prints the banner after the settings probe).
--data-dir PATH, --settings PATH, --dump-resolved-config, --ack-money-settings		Control plane, see Settings file.
--pool		Pool run-loop: embedded daemon + sharechain + Stratum.
--selftest	default	ABLA budget self-test, exit.
--ibd [--near-tip] [--auto-kick], --with-peer-verify, --max-seconds N (600)		Headers-first IBD / peer-verify harnesses against one BCHN peer.
--leg-c-capture [--rpc-conf PATH], --leg-c-capture-p2p [--p2p-port N] (18444)		Regtest capture harnesses; --rpc-conf defaults to ~/bch-regtest/bitcoin.conf here. --p2p-port is the leg-C BCHN regtest port, not the sharechain port (the catalog maps it to sharechain.listen; the parser does not).
--peer HOST[:PORT]	192.168.86.110:8333 (a developer-host default — always supply your own)	BCHN coin-P2P peer. Port 0 = no explicit peer → SeedTier discovery ladder (src/impl/bch/coin/embedded_daemon.hpp maybe_start_p2p).
--testnet / --testnet4 / --regtest	mainnet	Chain selection; also moves the default peer port (18333 / 28333 / 18444).
--anchor N	0	Cold-start ABLA floor anchor height.
--stratum [HOST:]PORT	off	Stratum listener.
--http [HOST:]PORT	off	Dashboard.
--rpc-conf PATH	—	BCHN bitcoin.conf for the external-RPC fallback (rpcuser/rpcpassword; endpoint is 127.0.0.1:<rpcport>).
--sharechain-addnode HOST:PORT (repeatable)	public defaults	Pin sharechain peers (92.53.224.27:9349 is the live public BCH sharechain seed named in the source).

No money flags on this binary: BCH has no --fee / --give-author / --node-owner-address in the parser (the catalog rows exclude C_BCH).

c2pool-bip110 — Bitcoin Knots BLAKE2b fork

Source: src/c2pool/main_bip110.cpp — print_banner() and the main() parse loop. Unknown flags are ignored silently (no trailing else), and the binary takes no --data-dir / --settings / --dashboard-dir: the dashboard is served from web-static relative to the working directory (web_server->set_dashboard_dir("web-static") in run_embedded), so deploy a web-static copy next to the binary and start it from that directory.

# Public fork pool (bip110.voidbind.com posture)
cd /opt/c2pool-bip110 && ./c2pool-bip110 --run --coin-p2p-discover \
  --coin-externalip <your-public-ip> --fork-checkpoint \
  --http 127.0.0.1:8086 --stratum 9336 --serve-mempool-txs \
  --give-author 0.1 --fee 0 --node-owner-address <your-BTC-address> \
  --bip110-sharechain --explorer

Flag	Default	Meaning
--version, -h / --help		Print and exit.
--run		Embedded daemonless BLAKE2b fork follower + Stratum. Without it (or with --selftest) the KAT self-test runs and exits. If neither --coin-p2p-discover nor --peer is given, discovery is switched on automatically.
--coin-p2p-discover	auto with --run	Discover NODE_BLAKE2B fork peers (DNS + fixed seeds).
--peer IP[:PORT] (repeatable)	port 8333	Explicit fork peer.
--coin-externalip IP	peer-echo auto	Operator-pinned reachable IP for self-advertisement (bare IP; port 8333 substituted).
--fork-checkpoint	off	Seed the Knots 961640 checkpoint for a fast proof.
--http [HOST:]PORT	off	Shared coin-generic dashboard (/, /node_info, /api/node_topology, /broadcaster_status).
--stratum [HOST:]PORT / --no-stratum	0.0.0.0:9336 on	Stratum listener; --no-stratum disables.
--serve-mempool-txs / --no-serve-mempool-txs	on	Include real network txs in served templates (M3 good-citizen); the --no- form is the coinbase-only escape hatch.
--bip110-sharechain	off	Arm the M3 sharechain mint on :9337 and dial the federation sharechain. First outbound is irreversible (params-freeze checkpoint). Absent → M2 header-follower only.
--sharechain-addnode HOST:PORT (repeatable)	beacon list	Override the default sharechain bootstrap beacons.
--explorer / --no-explorer	on	Loopback-only /api/explorer + raw-block retention.
--node-owner-address ADDR (alias --donation)	—	Node-owner fee destination and subsidy fallback when a miner's username has no resolvable address.
--give-author PCT (alias --dev-donation)	0.1 (catalog money.give_author_pct)	Author donation percent.
-f / --fee PCT	0	Node-owner fee percent.

---

API endpoints

Endpoint	Description
/local_stats	Local node statistics (peers, hashrates, shares)
/global_stats	Pool-wide statistics
/current_payouts	Current PPLNS payout distribution
/recent_blocks	Recently found blocks
/connected_miners	Connected stratum workers
/stratum_stats	Per-worker stratum statistics (hashrate, difficulty, accepted/rejected)
/sharechain/stats	Share chain state
/miner_thresholds	Minimum viable hashrate, dust range
/merged_stats	Merged mining block statistics
/current_merged_payouts	Current merged mining payouts
/recent_merged_blocks	Recent merged-mined blocks
/broadcaster_status	Parent chain broadcaster status
/api/explorer/getblockchaininfo	Chain info (loopback-only, requires explorer: true)
/api/explorer/getblockhash	Block hash by height (loopback-only)
/api/explorer/getblock	Full block JSON by hash or height (loopback-only)

See docs/DASHBOARD_INTEGRATION.md for the complete REST API reference and dashboard/explorer integration guide (and docs/FAQ.md for common questions).

Web dashboard — served from web-static/ by default:

xdg-open http://localhost:8080/

Lite block explorer — bundled Python app in explorer/ for browsing recent blocks:

# Enable in config to store blocks + serve REST API
explorer: true
explorer_url: "http://localhost:9090"

# Run the explorer UI against c2pool's API
python3 explorer/explorer.py --ltc-c2pool http://127.0.0.1:8080/api/explorer --web-port 9090

The explorer shows block details, decoded coinbase scripts, THE commitment proofs for c2pool-found blocks, and links to Blockchair for transactions/addresses outside the stored range.

Customization — both the dashboard (web-static/) and the explorer (explorer/explorer.py) are user-customizable components. Edit HTML/JS/CSS in web-static/ or modify explorer/explorer.py to change the design, add features, or integrate with your own infrastructure. Block explorer links default to Blockchair but can be overridden per-node via YAML config:

address_explorer_prefix: "https://your-explorer.example.com/address/"
block_explorer_prefix: "https://your-explorer.example.com/block/"
tx_explorer_prefix: "https://your-explorer.example.com/tx/"

---

Coinbase structure

Every block found by c2pool embeds structured data in the coinbase scriptSig:

[4]  BIP34 block height (consensus)
[44] AuxPoW merged mining commitment (when active)
[N]  Operator text (--coinbase-text, see per-lane defaults below)
[32] THE state root (sharechain state commitment)
[M]  THE metadata (pool analytics, fills remaining space)
     Total: 100 bytes (Bitcoin consensus limit)

The THE state root commits the sharechain state at block-find time (PPLNS distribution, chain height, difficulty). Any node can verify a found block's payouts match the committed state root.

Operator text defaults

--coinbase-text is capped at 64 bytes (20 when merged mining is active, since the AuxPoW commitment shares the same 100-byte budget).

Lane	Default operator text
LTC (c2pool)	/c2pool/
DASH (c2pool-dash) mainnet	/P2Pool-DASH/c2pool/
DASH (c2pool-dash) testnet / regtest	/P2Pool-tDASH/c2pool/

The DASH default embeds the canonical p2pool marker (COINBASEEXT from the p2pool-dash oracle networks/dash.py) because block explorers attribute blocks to a pool by coinbase text — chainz.cryptoid.info lists the pool as P2Pool-DASH and does not know the string c2pool. The c2pool/ suffix records which implementation mined the block. The coinbase text is not consensus-bearing (peers never re-derive it), so overriding it cannot orphan a share — but an override that drops /P2Pool-DASH/ makes your blocks unattributable on explorers.

DASH sources this default from its coin SSOT (src/impl/dash/config_pool.hpp); the same pattern is available for the other lanes but is not yet wired there.

---

Authority message blobs (V36)

# Create transition signal (authority key holder)
python3 util/create_transition_message.py create \
    --privkey <64-hex> \
    --from 36 --to 37 --msg "Upgrade to V37" --urgency recommended

# Pass blob at startup (node operator)
./c2pool --message-blob-hex 01a2b3c4...

See util/README.md for full documentation.

---

Private sharechains

# Start a private chain
./c2pool --network-id DEADBEEF12345678

# Join the same chain
./c2pool --network-id DEADBEEF12345678 -n OPERATOR_IP:9326

The --network-id overrides the IDENTIFIER hashed into every share's verification hash. Nodes without the correct ID cannot forge valid shares. See above for details.

---

Build targets

Target	Description
c2pool-ltc	Primary binary — release packages ship this per-coin name (c2pool is the dev-build alias)
c2pool-btc	Bitcoin parent (src/c2pool/main_btc.cpp)
c2pool-dgb	DigiByte Scrypt parent (src/c2pool/main_dgb.cpp; -DAUX_DOGE for embedded DOGE)
c2pool-bch	Bitcoin Cash parent (src/c2pool/main_bch.cpp)
c2pool-dash	Dash parent (src/c2pool/main_dash.cpp)
c2pool-bip110	BIP-110 BLAKE2b fork (src/c2pool/main_bip110.cpp)
test_hardening	Softfork gate + reply-matcher regression tests
test_share_messages	V36 authority message decrypt/verify tests
test_coin_broadcaster	Coin peer-manager and broadcaster tests

cd build && ctest --output-on-failure -j$(nproc)

---

Status

Area	Status
V36 share format (LTC parent chain)	Released (v0.2.0); prod cutover gated on crossing soak
V36 share format (DGB Scrypt parent chain)	Running — c2pool-dgb daemonless public node (dgb.voidbind.com), joined to the live DGB sharechain via --sharechain-addnode
Daemonless per-coin nodes (BTC, BCH, DASH)	Running — public voidbind nodes with no coin daemon on the serve path
Merged mining (DOGE, PEP, BELLS, LKY, JKC, SHIC)	Working
Embedded LTC SPV node	Working
Embedded DOGE SPV node	Working
Embedded BIP-110 daemonless pool (BLAKE2b fork)	Experimental (live on bip110.voidbind.com; fork-follow + Stratum mining + reward-safe mempool-serving on master #1439)
Coin daemon RPC/P2P	Hardened
Stratum mining server	Working
VARDIFF	Working
Payout / PPLNS	Working
Authority message blobs (V36)	Working
Solo / Custodial modes	Working
Test suite	1,875 test cases across 194 suites

Need a pool running today? frstrtr/p2pool-merged-v36 — production Python V36 pool (LTC + DGB + DOGE, Docker, dashboard).

---

Community

• Telegram: https://t.me/c2pooldev
• Discord: https://discord.gg/yb6ujsPRsv

---

V37 development

• V37 Purple Paper (Work Receipts design): https://frstrtr.github.io/c2pool/purple-paper.html
• Dev chat (Telegram): https://t.me/c2pooldev
• V37 dev-branch primitives (diff): https://github.com/frstrtr/c2pool/compare/master...v37-dev

---

License

• c2pool daemon (this repository): AGPL-3.0-or-later. Network use triggers the AGPL source-provision obligation.
• c2pool-core-engine (extracted primitive layer): Apache-2.0, in the separate c2pool-core-engine repository.
• Bundled src/btclibs/ and third-party crypto: retain their original MIT licenses (notices preserved in-file).
• V37 Purple Paper (frstrtr.github.io/c2pool): MIT License (as with the Bitcoin whitepaper). The remaining site articles are © technocore.one, all rights reserved.

Install guides

• Ubuntu / Debian / Linux
• macOS (Intel & Apple Silicon)
• Windows

See deploy/DEPLOY.md for HiveOS/MinerStat/RaveOS setup.