davideandClaude Opus 5
8dd913ec59
The max-amount checkbox sends amount_sats == the whole confirmed balance, so change came out at 0, the change output was dropped, and the transaction had a single output. bump_fee has nothing to shrink there: it raised RbfError every 30s until the reconciler abandoned the row six hours later. The RBF single-change-output limitation was a documented gap, but the UI made it the *default* withdrawal path. The extra-input fallback would not have helped this case: a transaction moving the entire balance already spends every UTXO the sender has. So the fix is at build time — build_signed_transaction never produces a change output below DUST_LIMIT_SATS, and never folds it into the fee either: - withdrawals pass reduce_amount_to_keep_change=True and move a dust limit less. The fee already comes out of the withdrawn amount by design, so this is the same rule applied a little harder, and Withdrawal.amount_requested_sats vs amount_sent_sats already existed to record the difference. - bets don't: the bet is a fixed price that can't be quietly reduced. A balance exactly equal to the bet is refused with balance_leaves_no_change (translated into all 7 languages, carrying required_extra_sats), which turns "a user's balance must never exactly equal the bet" from a documented assumption into an enforced one — and stops an unbumpable bet from holding a round open until the reconciler gives up on it. bump_fee's no-change guard stays: a single-output tx broadcast before this change can still be pending across the deploy, and it must fail loudly rather than start shrinking a recipient's output. Its test now hand-builds that shape, precisely because the builder no longer will. Co-Authored-By: Claude Opus 5 <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").