C++ reimplementation of forrestv/p2pool targeting the V36 share format with Litecoin + multi-chain merged mining (DOGE, PEP, BELLS, LKY, JKC, SHIC). DigiByte Scrypt support planned as an additional parent chain.
Bitcoin wiki: https://en.bitcoin.it/wiki/P2Pool
Original forum thread: https://bitcointalk.org/index.php?topic=18313
| Area | Status |
|---|---|
| V36 share format (LTC parent chain) | Active development |
| V36 share format (DGB Scrypt parent chain) | Planned |
| Merged mining (DOGE, PEP, BELLS, LKY, JKC, SHIC) | Working |
| Coin daemon RPC/P2P | Hardened (softfork gate, keepalive, timeouts) |
| Stratum mining server | Working |
| VARDIFF | Working |
| Payout / PPLNS | Working |
| Authority message blobs (V36) | Working |
| Test suite | 390 tests, all passing |
Need a pool running today?
frstrtr/p2pool-merged-v36 — production Python V36 pool (LTC + DGB + DOGE, Docker, dashboard).
# 1 — prerequisites (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
conan profile detect --force
# 2 — clone and build
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)Full step-by-step guide: doc/build-unix.md
# Integrated mode with embedded SPV (no separate LTC/DOGE daemons needed)
./src/c2pool/c2pool --integrated --net litecoin --embedded-ltc --embedded-doge \
--address YOUR_LTC_ADDRESS
# Or with external daemons + additional merged chains
./src/c2pool/c2pool --integrated --net litecoin \
--coind-address 127.0.0.1 --coind-rpc-port 9332 \
--rpcuser litecoinrpc --rpcpassword RPCPASSWORD \
--address YOUR_LTC_ADDRESS \
--merged DOGE:98:127.0.0.1:22555:dogerpc:dogepass \
--merged PEP:63:127.0.0.1:29377:peprpc:peppass \
--merged LKY:8211:127.0.0.1:9916:lkyrpc:lkypass
# Testnet quick smoke-test
./src/c2pool/c2pool --integrated --testnet
# Full option reference
./src/c2pool/c2pool --helpDefault ports
| Port | Purpose |
|---|---|
| 9326 | P2Pool sharechain (peer-to-peer) |
| 9327 | Stratum mining + HTTP API |
Merged mining chains
LTC and DOGE have built-in embedded SPV nodes — no separate daemon required. Other chains need their daemon running externally.
| Coin | chain_id | Daemon | --merged example |
|---|---|---|---|
| DOGE | 98 | Embedded SPV (or external) | DOGE:98:127.0.0.1:22555:user:pass |
| PEP | 63 | External (pepecoind) |
PEP:63:127.0.0.1:29377:user:pass |
| BELLS | 16 | External (bellsd) |
BELLS:16:127.0.0.1:19918:user:pass |
| LKY | 8211 | External (luckycoind) |
LKY:8211:127.0.0.1:9916:user:pass |
| JKC | 8224 | External (junkcoind) |
JKC:8224:127.0.0.1:9770:user:pass |
| SHIC | 74 | External (shibacoind) |
SHIC:74:127.0.0.1:33863:user:pass |
| DINGO | 98 | External (dingocoind) |
Cannot run with DOGE (same chain_id) |
LTC and DOGE use built-in embedded SPV nodes — zero external dependencies for the core LTC+DOGE setup. External daemons use createauxblock/submitauxblock RPC.
DigiByte Scrypt is planned as a second parent chain (--net digibyte), running its own P2Pool sharechain network. DGB Scrypt produces valid Scrypt PoW, so it can also merge-mine DOGE and the other AuxPoW coins.
See deploy/DEPLOY.md for HiveOS/MinerStat/RaveOS setup.
API endpoints (integrated mode)
GET /local_rate local pool hashrate
GET /global_rate network hashrate
GET /current_payouts PPLNS expected payouts
GET /recent_blocks blocks found by pool
GET /global_stats comprehensive pool stats
GET /sharechain/stats sharechain tracker data
GET /local_stats p2pool-compatible local stats
POST {jsonrpc} getinfo, getminerstats, getpayoutinfo, ...
Web dashboard — served by default from web-static/:
# Built-in dashboard
xdg-open http://localhost:8080/
# Custom dashboard directory
./src/c2pool/c2pool --dashboard-dir /path/to/my-dashboard ...See docs/DASHBOARD_INTEGRATION.md for the complete API reference and custom dashboard development guide.
Node operators distributing upgrade signals or pool announcements use the standalone Python 3 CLI in util/:
# authority key holder — create transition signal
python3 util/create_transition_message.py create \
--privkey <64-hex> \
--from 36 --to 37 --msg "Upgrade to V37" --urgency recommended
# node operator — pass blob at startup
./src/c2pool/c2pool ... --message-blob-hex 01a2b3c4...See util/README.md for full documentation.
c2pool supports configuration via CLI arguments, YAML config file, or both. CLI arguments always take priority over YAML values.
# Use a YAML config file
./src/c2pool/c2pool --config config/c2pool_testnet.yaml
# Or pass everything via CLI
./src/c2pool/c2pool --integrated --testnet --net litecoin \
--p2pool-port 19338 -w 19327 --web-port 8080 ...| CLI flag | YAML key | Default | Description |
|---|---|---|---|
--net |
— | — | Blockchain: litecoin, bitcoin, dogecoin |
--testnet |
— | off | Enable testnet mode |
--p2pool-port |
port |
9326 | P2P sharechain port |
-w / --worker-port |
stratum_port |
9327 | Stratum mining port |
--web-port |
http_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 |
--address |
— | — | Payout address |
--give-author |
donation_percentage |
0 | Developer donation % |
-f / --fee |
node_owner_fee |
0 | Node owner fee % |
--node-owner-address |
node_owner_address |
— | Node owner payout addr |
--redistribute |
redistribute |
pplns | Mode: pplns/fee/boost/donate |
--max-conns |
— | 8 | Target outbound P2P peers |
--stratum-min-diff |
min_difficulty |
0.001 | Vardiff floor |
--stratum-max-diff |
max_difficulty |
65536 | Vardiff ceiling |
--stratum-target-time |
target_time |
10 | Seconds between pseudoshares |
--no-vardiff |
vardiff_enabled |
true | Disable auto-difficulty |
--max-coinbase-outputs |
max_coinbase_outputs |
4000 | Max coinbase outputs |
--log-file |
log_file |
debug.log | Log filename |
--log-level |
log_level |
trace | trace/debug/info/warning/error |
--log-rotation-mb |
log_rotation_size_mb |
10 | Log rotation threshold (MB) |
--log-max-mb |
log_max_total_mb |
50 | Max rotated log space (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 |
--coinbase-text |
coinbase_text |
— | Custom coinbase scriptSig text (see below) |
--message-blob-hex |
— | — | V36 authority message blob |
--embedded-ltc |
— | off | Use embedded SPV for LTC (no litecoind needed) |
--network-id |
network_id |
0 | Private chain identifier (hex, see below) |
See config/c2pool_testnet.yaml for a complete example.
Every block found by c2pool embeds structured data in the coinbase scriptSig. The 100-byte scriptSig is partitioned as follows:
┌─────────────────────────────────────────────────────────────────┐
│ [4] BIP34 block height (consensus required) │
│ [44] AuxPoW merged mining commitment (when merged mining active)│
│ [N] Tag or operator text (see below) │
│ [32] THE state root (sharechain state commitment) │
│ [M] THE metadata (pool analytics, fills remaining space) │
└─────────────────────────────────────────────────────────────────┘
Total: 100 bytes (Bitcoin consensus limit)
Operator text (--coinbase-text)
By default, c2pool uses /c2pool/ (8 bytes) as the tag. Node operators
can replace this with custom text via --coinbase-text:
# Default: "/c2pool/" tag
./src/c2pool/c2pool --integrated ...
# Custom: your node name
./src/c2pool/c2pool --integrated --coinbase-text "EU-Node1" ...
# Custom: pool branding
./src/c2pool/c2pool --integrated --coinbase-text "MyPool.io" ...Size limits (enforced at startup):
| Mode | Max text | Reason |
|---|---|---|
| With merged mining | 20 bytes | AuxPoW commitment uses 44 bytes |
| Without merged mining | 64 bytes | No AuxPoW overhead |
c2pool is always identified by the combined donation address in coinbase outputs (visible in any block explorer) — the scriptSig tag is optional branding, not the primary identifier.
THE state root (32 bytes, always present)
Commits the sharechain state at block-find time:
- PPLNS weight distribution snapshot
- Sharechain height and chain parameters
- Epoch metadata (difficulty, pool hashrate)
This enables trustless checkpoints: any c2pool node can verify that a found block's PPLNS distribution matches the committed state root.
THE metadata (variable, fills remaining space after tag)
| Byte | Field | Description |
|---|---|---|
| 0 | version | Protocol version (0x01 = V36) |
| 1-4 | sharechain_height | Share chain height at block-find |
| 5-6 | miner_count | Unique miners in PPLNS window |
| 7 | hashrate_class | log2(pool hashrate in H/s) |
| 8-15 | chain_fingerprint | 0=public, SHA256d(PREFIX||IDENTIFIER)[0:8]=private |
| 16-17 | share_period | Current share period (seconds) |
| 18-19 | verified_length | Verified chain length |
Metadata is truncated from the end when space is limited (e.g., long operator text reduces metadata space).
c2pool supports private sharechains for isolated mining networks.
# Start a private chain (operator)
./src/c2pool/c2pool --integrated --network-id DEADBEEF12345678 \
--net litecoin --address YOUR_LTC_ADDRESS ...
# Join the same private chain (miner)
./src/c2pool/c2pool --integrated --network-id DEADBEEF12345678 \
-n OPERATOR_IP:9326 ...How it works:
The --network-id overrides the IDENTIFIER used in share consensus
verification. p2pool uses two-layer network isolation:
| Layer | Value | Security |
|---|---|---|
| Transport | PREFIX (derived from network-id) | Filters connections — visible on wire |
| Consensus | IDENTIFIER (= network-id) | Hashed into every share's ref_hash — secret |
A node that doesn't know the network-id cannot forge valid shares because the IDENTIFIER is hashed into every share's verification hash. Sharing the network-id with a miner grants them sharechain access.
Genesis behavior: When the chain is empty, c2pool automatically creates genesis shares — no special flag needed. The first miner solution becomes the genesis share, and the chain grows from there. Peers that connect later download shares from the genesis node.
Security: The IDENTIFIER is never stored raw on the blockchain — it is
the consensus secret. The chain_fingerprint in THE metadata is
SHA256d(PREFIX || IDENTIFIER)[0:4] — a 4-byte cryptographic fingerprint
using Bitcoin's standard double-SHA256. Even if the PREFIX is sniffed from
network traffic, the IDENTIFIER half requires 2^64 brute force to recover.
Blockchain scanners can group blocks by fingerprint without learning the
secret needed to join the chain.
Default --network-id 0 = public p2pool network (standard IDENTIFIER).
| Target | Description |
|---|---|
c2pool |
Primary binary |
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 |
Run all tests:
cd build && ctest --output-on-failure -j$(nproc)- Telegram: https://t.me/c2pooldev
- Discord: https://discord.gg/yb6ujsPRsv
See docs/DASHBOARD_INTEGRATION.md for the complete HTTP API reference, including:
- Native c2pool endpoints (hashrate, payouts, stats, blocks, miners)
- p2pool legacy endpoints (local_stats, web/version, etc.)
- Merged mining endpoints (merged_stats, recent_merged_blocks, discovered_merged_blocks, current_merged_payouts, etc.)
- JSON-RPC methods (getinfo, getminerstats, getpayoutinfo, submitblock, etc.)
Merged mining endpoints:
| Endpoint | Description |
|---|---|
/merged_stats |
Merged mining block statistics |
/current_merged_payouts |
Current merged mining payouts |
/recent_merged_blocks |
Recent merged-mined blocks |
/all_merged_blocks |
All merged-mined blocks |
/discovered_merged_blocks |
Merged block proofs |
/broadcaster_status |
Parent chain broadcaster status |
/merged_broadcaster_status |
Merged chain broadcaster status |
/network_difficulty |
Historical network difficulty |
For full field details and dashboard integration, see docs/DASHBOARD_INTEGRATION.md.