wheelofnames

Self-hosted API that renders wheel-of-names GIF animations and gacha wish MP4 animations with Remotion.

API

POST /api/gif
Content-Type: application/json
Accept: image/gif
Authorization: Bearer change-me

{
  "options": ["alice", "bob", "carol"],
  "winnerIndex": 1,
  "durationMs": 6500,
  "holdMs": 1200,
  "fps": 15,
  "size": 512,
  "theme": "classic"
}

Response is image/gif with winner metadata headers:

X-Wheel-Winner-Index
X-Wheel-Winner
X-Render-Duration-Ms

X-Wheel-Winner is URL-encoded so non-ASCII labels are safe in HTTP headers.

Gacha wish

POST /api/gacha
Content-Type: application/json
Accept: video/mp4
Authorization: Bearer change-me

{
  "label": "Pizza",
  "rarity": 5,
  "fps": 24,
  "width": 640
}

Renders a 7-second wish animation in the style of a gacha game: a meteor coloured by rarity (blue 3★, purple 4★, gold 5★) flies in from the left across a night sky and bursts in a white flash where the rank emblem appears, and the label is revealed beside a rank emblem (B, A, S) with its stars popping in. Each tier is louder than the one below: 4★ adds a bigger meteor, a lens flare, impact shake, and a double shockwave; 5★ adds a rainbow sunburst before landing, a gold sky flood, a starburst, counter rotating rays, falling sparkles, and a sheen across the emblem. The per-tier table lives in src/remotion/gacha-timeline.js. rarity is required; fps is 24 or 30; width is 640 (360 tall) or 854 (480 tall). Optional seed (integer, 0 to 2147483647) lays out the twinkling stars and particles; when omitted the service picks a random one, so every roll draws a different sky. The caller chooses the result and its rarity — the service only draws it.

Gacha wish beta

POST /api/gachabeta takes the same body and returns the same response as /api/gacha, rendering an 8-second beta style instead: a cosmic, astrology themed night sky with toon-shaded clouds and stars, without outlines, seen through a perspective action camera:

The sky fades in around a main cloud. A comet approaches from behind, lights the cloud's rim, then punches through it with scattered puffs and an impact ring.
The camera follows the flying star as its light and lens flare intensify, ending in a starburst and white flash.
The food label appears inside an astrology ring with rank SSS.

The caller randomly chooses the food and sends it as label (for example, "Bún bò"). The beta reveal always shows SSS; rarity still chooses the comet's blue, purple, or gold palette. /api/gacha keeps its existing ranks.

Response is a silent H.264 video/mp4 (Telegram plays it as an animation) with X-Gacha-Rarity and X-Render-Duration-Ms headers. Both routes share the MAX_CONCURRENT_RENDERS slots. All visuals are drawn procedurally; no game assets are used.

Local

Install dependencies and Chromium once:

npm install
npm run browser:ensure

Start the local API:

npm run dev

Generate GIF files locally

Generate the quick smoke fixtures at the git-ignored paths fixtures/smoke.gif and fixtures/gacha-5-star.mp4:

npm run render:smoke

Generate the complete fixture set at fixtures/smoke.gif, fixtures/vietnamese.gif, fixtures/sixteen-options.gif, and fixtures/gacha-{3,4,5}-star.mp4:

npm run render:fixtures

Render a custom GIF directly without starting the API server:

npm run render:local -- `
  --output wheel.gif `
  --option "Chiều nay uống CraneTea" `
  --option "Chiều nay uống CraneTea" `
  --option "Cà phê" `
  --winner 1

macOS, Linux, or Git Bash:

npm run render:local -- \
  --output wheel.gif \
  --option "Chiều nay uống CraneTea" \
  --option "Chiều nay uống CraneTea" \
  --option "Cà phê" \
  --winner 1

--winner is a zero-based index and is random when omitted. Run npm run render:local -- --help for duration, hold, FPS, size, theme, and timeout options. The documented root wheel.gif and fixtures/*.gif/*.mp4 outputs are git-ignored and safe to delete; custom output paths may need their own ignore rule.

Verify

Run the API smoke test and quality gates:

npm run api:smoke
npm run lint
npm run typecheck
npm test

Deploy

Use a container runtime first. Static-only platforms cannot satisfy POST /api/gif because Remotion server rendering needs Node, Chromium/runtime dependencies, and FFmpeg/compositor support.

docker build -t wheelofnames .
docker run --rm -p 3000:3000 -e API_TOKEN=change-me wheelofnames

Recommended starting resources: 1-2 vCPU and 1-2 GB RAM, with MAX_CONCURRENT_RENDERS=1. RENDER_TIMEOUT_MS defaults to 15000 and is raised to Remotion's 7000ms browser timeout floor when configured lower. API_TOKEN is required when NODE_ENV=production.

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