@opys/bifrost

Mint a Bifrost-compatible JWT locally so opys's runClient can launch Minecraft against a self-hosted Yggdrasil server without going through the OAuth /token flow. Signed with Ed25519 (alg EdDSA).

npm install @opys/bifrost

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

export default defineConfig({
  output: 'opys.json',
  plugins: [minecraft('1.20.1')],
  manifest: {
    /* … */
  },
  // runClient runs every launch on the launch machine — the right
  // place for machine-local paths and a freshly-minted auth token.
  runClient: (manifest) => {
    const auth = resolveBifrost({
      privateKey: process.env.BIFROST_PRIVATE_KEY,
      username: 'deitylamb',
      uuid: '00000000-0000-0000-0000-000000000000',
    });
    return {
      vars: {
        ...manifest.vars,
        root: userDataDir('my-pack'),
        auth_player_name: auth.username,
        auth_uuid: auth.uuid,
        auth_access_token: auth.token,
      },
    };
  },
});

Pure helper — no plugin factory. Pair it with @opys/authliberty to wire the -javaagent that points Minecraft at your Bifrost server.

Part of the opys toolkit; re-exported by @opys/minecraft.