@frontle-game/borders

The pure geography engine behind Frontle — a daily "connect two countries through their land borders" game built for MiniPay on Celo.

Zero dependencies. Works in the browser, Node, and edge runtimes.

• Country land-border graph (symmetric, verified) for 150+ countries.
• shortestPath / distance via BFS.
• Deterministic daily challenge — same date → same puzzle for everyone.
• Guess evaluation (Travle-style: a guess is valid if it borders any known country) with a green/yellow/red quality signal, and victory when start and end connect through known countries.

Install

npm i @frontle-game/borders

Usage

import {
  dailyChallenge, tryGuess, resolveCountry, connectsThroughKnown,
} from "@frontle-game/borders";

// Today's puzzle (deterministic by UTC date):
const challenge = dailyChallenge();
// → { start: "Portugal", end: "Germany", optimal: 2, path: [...], level: "medium" }

// A running game state:
let state = { challenge, chain: [], solved: false };

// The player types a country (any language name → canonical via resolveCountry):
const guess = resolveCountry("españa"); // → "Spain"
const result = tryGuess(state, "españa", guess);
// → { ok: true, solved: false, quality: "green", country: "Spain", ... }

API

| Export | What it does | |--------|--------------| | shortestPath(a, b) | Shortest border path, or null if unconnected | | distance(a, b) | Hops between two countries (Infinity if none) | | dailyChallenge(seed?, level?) | Deterministic challenge for a day/level | | dailyChallenges(seed?) | One challenge per difficulty | | randomChallenge(level?) | A random challenge (for practice) | | tryGuess(state, raw, canonical) | Validate + evaluate a guess | | countryQuality(c, start, end) | "green" \| "yellow" \| "red" | | connectsThroughKnown(start, end, known) | Victory check | | nextHintCountry(state) | Next country on an optimal path | | resolveCountry(input) | Canonical name from fuzzy/aliased input | | suggest(input, limit?) | Autocomplete suggestions | | COUNTRIES, COUNTRY_NAMES, getCountry, areNeighbors | The graph |

License

MIT © Frontle