a4a894e1969652cd660ffeb9b5382d89837ce5da
P1 audits / fixes:
* Bitcoin Core RPC now retries up to 3 times with linear backoff on
transport errors, 5xx responses, and warm-up/loading RPC errors
(code -28). Hard "no" answers (block-not-found etc.) bubble up
immediately so we don't mask real errors.
* WebSocket hub disconnects clients that miss 6 consecutive broadcasts
(~30s with the default poll cadence). Stuck readers no longer hold
stale snapshots indefinitely or freeze hub state.
* ZMQ subscriber freshness: aggregator records the last-event
timestamp, surfaces zmq_enabled / has_last_zmq_event /
last_zmq_event_age in the snapshot. /healthz flags zmq_stale when
the gap exceeds 30 minutes.
* /healthz expanded with submit_attempts / submits_confirmed /
submit_gap, fallback_submits_total + last_fallback_*, and the zmq
staleness check. Now usable as a real-world ops dashboard signal.
Block-broadcast fallback (new feature):
* ckpool patch 0004: hooks local_block_submit to write the raw block
hex to <logdir>/pending-blocks/<height>-<hash16>.hex right before
invoking generator_submitblock. Unlinks on success. ckpool's normal
flow is otherwise untouched.
* api/internal/blocksubmit: watcher polls the dir every 5s. Files
sitting longer than the grace window (default 30s, configurable)
are re-broadcast through operator-supplied backup RPC URLs in
sequence. Treats both null and any "duplicate*" reject reason as
success (the block landed). Pre-checks the primary chain first so
a stale file from a successful-but-unlinked submit gets cleaned
up without bothering fallbacks.
* Aggregator records each successful fallback submission as a
persistent counter and surfaces it in the snapshot so the UI can
show a "primary bitcoind isn't accepting submits" alert.
* Config: BACKUP_RPC_URLS (comma- or newline-separated, with
optional inline credentials) plus PENDING_BLOCKS_DIR and
PENDING_BLOCKS_GRACE. URLs are parsed via net/url so
https://user:pass@host:port/ works cleanly.
The fallback is opt-in and disabled by default. Once enabled with at
least one URL, a primary bitcoind outage at the moment of solving no
longer means a lost block — kamado-api re-broadcasts via whichever
backup the operator trusts (a second self-hosted node, an
authenticated public RPC service, etc.).
Kamado Pool
A modern, feature-complete solo Bitcoin mining pool built on a patched fork of CKPool, with a real-time web dashboard and a Go-based API middleware that surfaces everything CKPool knows.
Why Kamado?
Existing CKPool-based solutions (like Bassin for Umbrel) read only a handful of periodic stats files and miss most of CKPool's rich data. Kamado talks directly to CKPool's Unix socket API to expose:
- Real-time per-client data: hashrate, difficulty, user agent, hardware detection
- Full block-found history with height, hash, reward, and solving worker
- Per-worker and per-client best share tracking (current + all-time)
- Network difficulty, pool efficiency, expected time to block
- Live dashboard updates via WebSocket (no 60-second file polls)
Architecture
┌────────────────────────────────────────────────────┐
│ ckpool-solo (C) ──Unix socket──► kamado-api (Go) │
│ ports: 3333 ports: 80 │
│ │
│ ▲ stratum ▲ HTTP/WS │
│ │ │ │
│ Miners Browser │
│ │
│ bitcoind ◄──── RPC + ZMQ ────── ckpool + kamado-api│
└────────────────────────────────────────────────────┘
Three main components:
| Component | Language | Purpose |
|---|---|---|
ckpool/ |
C | Stratum server, share validation, block submission |
api/ |
Go | Socket client, REST/WebSocket API, persistence |
ui/ |
Svelte | Real-time dashboard |
Phases
- Phase 1 — Fork & fix CKPool, build infrastructure
- [~] Phase 2 — Go API middleware
- Phase 2a: CKPool socket client, bitcoind RPC, state aggregator, REST API
- Phase 2b: CKPool log tailer, block history, stdlib WebSocket push
- Phase 2b.5: ZMQ block notifier, SQLite persistence (deferred until s9pk repo exists — need real Go build env for new deps)
- ckpool patch 0001: expose
besteverin runtime socket JSON so the UI can show "this round" and "all-time" best share side by side - [~] Phase 3 — Svelte UI dashboard (skeleton: header, pool overview, miners table, blocks, best shares leaderboard; live WS updates)
- Phase 4 — Monorepo Docker build:
kamado-apiembedsui/distvia//go:embedand serves it at/. The api Dockerfile has a node stage that builds the UI before the Go stage embeds and builds the binary; docker-compose uses the repo root as build context so bothapi/andui/are visible. - Phase 5 — Testing (regtest, testnet4), polish
Quick start (dev)
cp .env.example .env # set POOL_BTCADDRESS and bitcoind creds
make up # build + start ckpool + api
curl localhost:8080/api/health
curl localhost:8080/api/pool
REST endpoints:
| Route | Returns |
|---|---|
GET /api/health |
CKPool + bitcoind health |
GET /api/pool |
Pool stats + derived hashrate windows + chain info |
GET /api/users |
All users from users socket command |
GET /api/workers |
All workers from workers socket command |
GET /api/clients |
All connected stratum sessions (useragent, IP, diff) |
GET /api/blocks |
Recent solved blocks (in-memory ring, SQLite in Phase 2b.5) |
GET /api/snapshot |
Full merged snapshot (everything) |
GET /api/ws |
WebSocket push: full snapshot on every refresh + on solve |
StartOS packaging lives in a separate repository.
Upstream
CKPool by Con Kolivas: https://bitbucket.org/ckolivas/ckpool
Pinned commit: see ckpool/CKPOOL_COMMIT
License
GPL-3.0. CKPool itself is distributed under GPL-3.
Languages
Go
46.7%
Svelte
36.4%
Shell
9.2%
TypeScript
4.7%
Dockerfile
1.4%
Other
1.5%