Bifrost

The resolveBifrost function, from @opys/minecraft.

Makes a player's login token, at launch.

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

export default defineConfig({
  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',
        }),
      },
    },
  }),
});

resolveBifrost signs a token that a Bifrost server accepts, with a private key you hold.

It is not a plugin

It does not go in plugins, and it adds nothing to the bundle.

Why: a token belongs to one player and expires. A bundle is the same for everyone and lasts. So the token is made in run, on the player's machine, at every launch.

Options

Option	What it is
privateKey	An Ed25519 private key, as PKCS#8 PEM.
username	The player's name.
uuid	The player's ID.
expiresIn	Lifetime in seconds. Default: 24 hours.

What it returns

{ username, uuid, token }: exactly the three variables minecraft leaves open. Spread it into vars.

Good to know

Keep the key out of manifest

Everything under manifest is copied into the bundle, and a bundle is a zip anyone can open. Read the key from the environment, inside run.

• The key may be one line, with \n for line breaks. Handy for an environment variable.
• Pair it with authliberty, which points the game at your server.