client_ip() read the first element of X-Forwarded-For, which is correct only if
the proxy replaces the header. Caddy appends the peer address to whatever the
client sent, so element 0 was whatever the caller claimed: rotating a fake value
per request minted a fresh identity every time and walked straight through the
login and registration throttles (B-33) and the SSE per-IP subscriber cap
(B-38). Only the per-username login bucket, which doesn't key on the IP, still
bit.
Both halves of the audit's fix, since they hold independently:
- the Caddyfile overwrites the header with `header_up X-Forwarded-For
{remote_host}`, so what reaches the app is the actual peer and nothing else.
This is the one that makes the app's assumption true at the source.
- client_ip() reads the *last* hop rather than the first — the element written
by the hop closest to us, i.e. by our own proxy. Exactly one trusted proxy
sits in front of the app (`app` is only `expose`d on the compose network,
never published to the host), so that element is the real peer.
An empty or comma-only header now falls back to request.client.host instead of
returning "", which was its own shared-bucket evasion.
Regression tests both sides: two requests spoofing different prefixes must key
to the same IP, and the Caddyfile must keep the header_up directive (checked by
`caddy validate`).
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").