davideandClaude Opus 5
8a0ebecfcc
ElectrumListener._run_once assigned self.client before subscribe_headers() returned, so there was a window — one round-trip wide, at process start — where the connection looked alive while tip_height was still its initial 0. "client is not None" is what every consumer reads as "the chain is reachable", RoundScheduler._tick included, and a round closing inside that window recorded tip_at_close = 0. The very first header we then learned about — the current tip, a block mined *before* the round closed, whose hash was already public while bets were still open — satisfied tip_height > tip_at_close and became the draw's entropy. The draw's whole guarantee is that its seed did not exist yet when betting stopped. Two changes, defending different things: - The client is published only once the first header has been applied, so "client is not None" now means "reachable *and* we know where the chain is". During the window consumers see no connection, which is honest: a bet gets the same 503 it already gets while disconnected, and the background tasks skip a cycle as they already do. - _wait_for_next_block treats a baseline of 0 as *unknown*, not as height zero: it adopts the first height it learns as the baseline, waits for a block strictly after it, and records draw_baseline_tip_unknown so the extra block of waiting is explainable from /admin. Unreachable via the listener now, but it is the local statement of what the draw requires, and nothing else in that function would notice if the invariant stopped holding. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
PLM Lottery
A periodic-round lottery system built on PLM, a Bitcoin-like coin (mainnet). Each user gets a dedicated server-derived P2WPKH address; they deposit PLM to that address, place a fixed-cost bet to enter the current round, and when the round closes a winner is drawn who receives 70% of the prize pool (the remaining 30% goes to fees).
This is a custodial system: private keys are generated and held server-side, encrypted at rest. See CLAUDE.md for the full architecture, domain decisions, and known gaps before treating this as production-ready.
Quick start
The server always runs via Docker (app + Caddy reverse proxy with automatic
TLS) — in dev and production alike, with only SITE_ADDRESS differing
between the two. There's no supported way to run uvicorn directly; the
venv is only for local tooling (tests, Alembic migrations, the one-time key
scripts) — see CLAUDE.md.
cp .env.example .env # then fill in the generated secrets, see docs/setup.md
mkdir -p data/db data/keys data/logs
docker compose run --rm app python scripts/generate_master_key.py
docker compose up -d --build
Open https://localhost/ for the test UI, https://localhost/admin for the
admin dashboard (a self-signed-certificate warning on first visit is
expected in dev — accept it, or use curl -k). The interactive API docs at
/docs are disabled by default (they'd otherwise expose the whole API
surface, admin endpoints included) — set ENABLE_API_DOCS=true in .env to
enable them.
See docs/setup.md and docs/running-the-server.md for the full walkthrough (secrets, master key generation, production TLS with a real domain).
Documentation
- CLAUDE.md — architecture, commands, domain decisions, known gaps (for anyone/anything working on the code)
- flowchart.mmd — the source-of-truth flow diagram the implementation follows node-by-node
- docs/setup.md — one-time setup (secrets, master key, migrations)
- docs/running-the-server.md — how to launch it (local venv vs. Docker+Caddy, dev vs. production TLS)
- docs/guida-utente.md — end-user guide to the test UI (Italian)
- docs/guida-admin.md — admin dashboard guide (Italian)
Tech stack
Python (FastAPI, SQLAlchemy async + Alembic, Argon2 + JWT auth), Electrum protocol for PLM network access (no full node), Docker + Caddy for deployment. See CLAUDE.md for the complete list and the reasoning behind each choice.
Testing
python -m pytest # all tests
python -m pytest tests/unit/test_hd.py # one file
232 unit tests cover HD derivation, PSBT building, the Electrum client, bets, deposits, withdrawals, the round/draw engine, RBF fee-bumping, admin config, the pending-inclusive balance calculation, and the SSE push channel. No automated integration tests against a live Electrum connection — mainnet verification so far has been manual (see CLAUDE.md's "Project status").