`bump_fee` only required `change > fee delta`. A change at the 294 sat minimum (a full-balance
withdrawal) shrank to ~153 sat after the very first minimum bump, relay policy refuses a
replacement with a sub-dust output, and the bumper tried again every 30 seconds for ever, with
nothing but a log line to show for it.
- When what would be left of the reducible output (the user's change, a payout's bump
reserve) is under DUST_LIMIT_SATS the output is dropped and its whole value goes to the fee:
that replacement is valid and the last one possible. If the output does not exist, or even
its whole value is below BIP125's minimum increase (vsize x 1 sat/vB), RbfError. The
recorded fee rate uses the replacement's own, smaller, size.
- RbfError now carries a `reason` (`change_too_small`, `max_fee_rate`, `replacement_rejected`);
RbfBumper._record_failure writes one `rbf_bump_failed` row {pending_transaction_id, kind,
txid, reason, message[:200]} with the row's user_id/round_id, in a transaction of its own,
once per (current txid, reason) - the audit log is the dedupe clock (AUD-09) - and the pending
row is untouched. A new txid or a new reason writes a new row.
- bump_fee's docstring no longer cites the "bet without change" case that B-62 removed.
No existing test changed (all bumps they make leave a change well above dust). New
tests/unit/test_rbf_dust.py: the 294 sat case end to end (recipient untouched, whole change to
the fee, last bump impossible), the exact boundary (leaves 294 kept / leaves 293 dropped), a
change under the minimum increase, a payout's reserve dropped with the winner and fee outputs
byte-identical, and the audit rows for each reason, once per pair, new row on a new txid or
reason, round/user attribution. Mutation-checked: the dust test of the output and the
once-per-pair check 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
681 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").