Hold BTC
Arcade game: fly a Bitcoin through candlestick obstacles.
- Play is free.
- 1000 sats on Lightning unlocks one ranked run.
- Ranked scores are replayed on the server, then published with a site Nostr key.
- Players log in with their own Nostr account.
- Site: holdbtc.io
Stack
Next.js 15, TypeScript, Tailwind CSS, Canvas, Strike, Nostr.
Run
npm install
npm run dev
Create .env.local:
STRIKE_API_KEY=
STRIKE_API_URL=https://api.strike.me
RANKED_TOKEN_SECRET=
HOLD_BTC_NSEC=
UPSTASH_REDIS_REST_URL=
UPSTASH_REDIS_REST_TOKEN=
BANNED_PUBKEYS=
HOLD_BTC_NSEC is a dedicated key used only to sign paid scores. It is not a player account.
UPSTASH_REDIS_REST_URL / UPSTASH_REDIS_REST_TOKEN point at the Redis that enforces one payment, one ranked run. With the Vercel KV / Upstash integration, KV_REST_API_URL / KV_REST_API_TOKEN work instead. They are required on Vercel and in production (next start), where the server throws if neither pair is set; next dev falls back to an in-process Map.
BANNED_PUBKEYS is an optional comma-separated list of 64-char hex pubkeys (not npub). A listed key is hidden from Global Rank and cannot buy a ranked run, submit a score, or share a note. Entries that are not hex are ignored with a warning in the logs. When the variable is empty, the list in lib/security/blockList.ts is used instead. On Vercel, a changed value takes effect on the next deployment: use Redeploy, no code change needed.
Per-IP rate limits read only the x-vercel-forwarded-for header that Vercel sets. Off Vercel (including next dev) it is missing, so all clients share one limit.
Ranked runs
- Log in with Nostr (extension recommended).
- Pay 1000 sats.
- Play one run. Flaps are recorded.
- The server replays that run and publishes the result.
- Global Rank lists only those events.
Free runs stay off the board.
Layout
app/ pages and API
components/ UI and canvas
hooks/ Nostr and payment state
lib/game/ physics, replay, render
lib/nostr/ relays and site publish
lib/payments/ Strike
lib/security/ tokens and rate limits
License
MIT
