The pool normally holds exactly the round's bet outputs and the payout spent them all for exactly the pool amount, so it had no change output: bump_fee could never accelerate it, and a payout stuck in a mempool (never abandoned while a server knows it) kept the round in `paying_out` and the whole lottery stopped. - build_payout_transaction always has three outputs: winner, fee address, and a bump reserve of max(DUST_LIMIT_SATS, estimate_vsize(inputs, 3) * 10 sat/vB) paid to the reserve address m/84'/746'/0'/1/0. The reserve comes out of the platform's 30%, the network fee still out of the winner's 70%. Input value beyond winner share + commission (only rounds opened before the per-round pool address) is folded into the reserve output if >= dust, left to the network fee otherwise. `change_address` is replaced by `reserve_address`. - `rounds.bump_reserve_sats` (Alembic e5a91c3d7b26, plain add_column) is written with the payout intent before the broadcast; /admin/rounds returns it. - bump_fee takes the increase from the reserve output for a payout (_find_reducible_output; a payout already in flight with a change to the pool still falls back to that), never from the winner or fee-address outputs. - payout_config_problem / rounds_can_open (RND-40): a bet amount and fee rate under which a round of 1 or of MAX_PARTICIPANTS_PER_ROUND participants could not cover the network fee, the reserve and dust outputs opens no round (lottery_configured=false); PUT /admin/config refuses such a bet amount or fee rate with 422 config_not_payable, judged on the resulting values, since the payout reads the fee rate live. Ambiguity resolved: the reserve output and any excess input are one output (RND-23 says one output to the reserve address), and bump_reserve_sats records that output's initial value. DAT-22's "abandon clears all amounts" stays with B-96. Tests changed because the spec changed: the four test_payout_builder tests asserted the old two/three-output shape with change to the pool and the fee address receiving the whole 30%; the whitespace fee_address test now spells out the amounts rounds_can_open reads. New: reserve sizing, payout with 1 and with 400 participants (inputs = outputs + fee to the satoshi), exact commission/reserve/dust boundary, excess folded or left to the fee, a real payout bumped out of its reserve with the other outputs byte-identical and bumped five times, the old reserve-less shape still raising RbfError, the scheduler output addresses and recorded amounts, payability boundaries found independently by bisection, no round / unconfigured flag for an unpayable config, a round in progress surviving it, PUT /admin/config refusals and the migration column. Mutation-checked: dropping the reserve lookup in bump_fee and the payability check in rounds_can_open each fail tests. Co-Authored-By: Claude Sonnet 5.5 <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)
- docs/README.md — index of all documentation (docs-first, single source of truth, one ADR per decision: docs/adr/)
- docs/come-funziona.md — the specification (Italian): how the platform works, with diagrams and traceable requirement IDs; it indexes every per-topic document (flows, architecture, data model, API, security, audit log, operations, decisions and limits, bug history). docs/processo-di-modifica.md describes how a change goes from the spec to the code
- docs/setup.md — one-time setup (secrets, master key, migrations)
- docs/running-the-server.md — how to launch it with 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
637 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").