@opys/bifrost

Bifrost for opys. resolveBifrost() makes a player's login token for a Bifrost server, at launch.

npm install -D @opys/dev @opys/bifrost @opys/minecraft-vanilla @opys/java

Example

// opys.config.mjs
import { defineConfig, userDataDir } from '@opys/dev';
import { java } from '@opys/java';
import { minecraft } from '@opys/minecraft-vanilla';
import { resolveBifrost } from '@opys/bifrost';

export default defineConfig({
  output: 'game.opys',
  plugins: [minecraft({ version: '1.21.1' }), java({ version: '21' })],
  manifest: {
    command: '@minecraft.command',
    args: ['@minecraft.jvmArgs', '@minecraft.mainClass', '@minecraft.gameArgs'],
    workdir: '${game_directory}',
  },
  run: (manifest) => ({
    manifest: {
      vars: {
        ...manifest.vars,
        root: userDataDir('my-pack'),
        ...resolveBifrost({
          privateKey: process.env.BIFROST_PRIVATE_KEY,
          username: 'Player',
          uuid: '00000000-0000-0000-0000-000000000001',
        }),
      },
    },
  }),
});

Options

Option	What it is
privateKey	An Ed25519 private key, as PKCS#8 PEM. One line with \n works too.
username	The player's name.
uuid	The player's ID.
expiresIn	Lifetime in seconds. Default: 24 hours.
now	When the token is issued, a Date or milliseconds. Default: now.

What it adds

Nothing in the bundle. It is not a plugin and does not go in plugins: a token belongs to one player and expires, so it is made in run, on the player's machine, at every launch.

Variables, at launch

The three that vanilla Minecraft leaves open.

// what resolveBifrost returns
{
  username: 'Player',
  uuid: '00000000-0000-0000-0000-000000000001',
  token: '<a signed token>',
}

Keep the key out of manifest: everything there is copied into the bundle, and a bundle is a zip anyone can open.

Every option

Each option, in each way it is used.

// a token for one player, valid for 24 hours
resolveBifrost({
  privateKey: process.env.BIFROST_PRIVATE_KEY,
  username: 'Player',
  uuid: '00000000-0000-0000-0000-000000000001',
});

// a shorter life, in seconds
resolveBifrost({
  privateKey: process.env.BIFROST_PRIVATE_KEY,
  username: 'Player',
  uuid: '00000000-0000-0000-0000-000000000001',
  expiresIn: 60 * 60,
});

// issued at a time you name, for a test that must give the same token twice
resolveBifrost({
  privateKey: process.env.BIFROST_PRIVATE_KEY,
  username: 'Player',
  uuid: '00000000-0000-0000-0000-000000000001',
  now: new Date('2026-01-01T00:00:00Z'),
});

Documentation

• The full page: every option, and why it works this way
• The format: what a manifest is made of

Part of opys. Also exported by @opys/minecraft.