@tournamental/bracket-engine

Pure-function bracket prediction engine for Tournamental. Powers the FIFA World Cup 2026 bracket prophet flow in the browser and the API.

Surface:

• tournament -- Tournament, Team, Group, KnockoutFixture types.
• cascade -- resolve a partial prediction's downstream tree against a tournament plus optional actual results.
• score -- long-shot-rewarding score model (docs/16, docs/24).
• standings -- group-stage standings calculator.
• vstamp -- content-hashed, signed prediction-receipt envelope.
• fixtures-2026 -- vendored FIFA WC 2026 tournament JSON.

Full background: docs/16-game-modes-and-scoring.md and docs/17-vstamp-and-prediction-iq.md.

Install

npm install @tournamental/bracket-engine @tournamental/spec

30-second example

import { loadFixtures2026 } from "@tournamental/bracket-engine";
import { cascadeBracket } from "@tournamental/bracket-engine/cascade";
import { scoreBracket } from "@tournamental/bracket-engine/score";

const tournament = loadFixtures2026();

// User pre-picks just the final
const userPicks = {
  winners: { FINAL: "ARG" },
};

// Cascade fills in the implied earlier rounds
const cascaded = cascadeBracket(tournament, userPicks);

// Score against (partial or complete) actual results
const score = scoreBracket(tournament, cascaded, /* actuals */ {});
console.log(score.totalPoints);

Subpath imports keep client bundles small

vstamp imports node:crypto, so it is NOT re-exported from the package root. Browser bundles only need tournament, cascade, score, standings. Server-side consumers import VStamp directly:

import { signBracket } from "@tournamental/bracket-engine/vstamp";

Open source and contributor revenue

Tournamental is Apache-2.0 licensed. Contributors share platform revenue through Drips Network. See docs/19-open-source-and-contributor-revenue.md.

Repo and docs

• Source: https://github.com/0800tim/tournamental
• Site: https://tournamental.com
• Issues: https://github.com/0800tim/tournamental/issues

Licence

Apache-2.0. See LICENSE.