Don't trust it. Re-run it.

import hashlib, struct

DOMAIN = "oomi:mutation:v1"
RULE = "oomi-rules/0.3"
TRAITS = [  # order defines trait index i
    ("aura", [("Signal Cyan", 34), ("Deep Plasma", 26), ("Dusk Violet", 18), ("Tidal Teal", 14), ("Halo Gold", 8)]),
    ("earGlow", [("Dim", 22), ("Soft", 34), ("Bright", 28), ("Radiant", 16)]),
    ("droplets", [("Still", 30), ("Drifting", 38), ("Orbiting", 20), ("Swarming", 12)]),
    ("pattern", [("Marbled", 36), ("Rippled", 26), ("Crystalline", 22), ("Static", 16)]),
    ("temperament", [("Curious", 30), ("Playful", 24), ("Serene", 20), ("Mischievous", 16), ("Focused", 10)]),
]

def lp(s: str) -> bytes:
    b = s.encode()
    return struct.pack(">I", len(b)) + b

def seed(epoch: int, identity: str, root_hex: str, entropy_hex: str, rule: str = RULE) -> bytes:
    pre = lp(DOMAIN) + struct.pack(">I", epoch) + lp(identity) + bytes.fromhex(root_hex) + lp(rule) + bytes.fromhex(entropy_hex)
    return hashlib.sha256(pre).digest()

def derive(epoch, identity, root_hex, entropy_hex):
    s = seed(epoch, identity, root_hex, entropy_hex)
    out = {}
    for i, (name, opts) in enumerate(TRAITS):
        u = struct.unpack(">I", hashlib.sha256(s + struct.pack(">I", i)).digest()[:4])[0] / 2**32
        total, acc = sum(w for _, w in opts), 0.0
        for value, w in opts:
            acc += w / total
            if u < acc:
                break
        out[name] = value
    return s.hex(), out

if __name__ == "__main__":
    h = lambda t: hashlib.sha256(t.encode()).hexdigest()
    print(derive(7, "oomi:flagship", h("snapshot"), h("entropy")))

import { createHash } from "node:crypto";

const sha = (b) => createHash("sha256").update(b).digest();
const u32 = (n) => { const b = Buffer.alloc(4); b.writeUInt32BE(n); return b; };
const lp = (s) => { const b = Buffer.from(s, "utf8"); return Buffer.concat([u32(b.length), b]); };

const TRAITS = [
  ["aura", [["Signal Cyan", 34], ["Deep Plasma", 26], ["Dusk Violet", 18], ["Tidal Teal", 14], ["Halo Gold", 8]]],
  ["earGlow", [["Dim", 22], ["Soft", 34], ["Bright", 28], ["Radiant", 16]]],
  ["droplets", [["Still", 30], ["Drifting", 38], ["Orbiting", 20], ["Swarming", 12]]],
  ["pattern", [["Marbled", 36], ["Rippled", 26], ["Crystalline", 22], ["Static", 16]]],
  ["temperament", [["Curious", 30], ["Playful", 24], ["Serene", 20], ["Mischievous", 16], ["Focused", 10]]],
];

export function derive(epoch, identity, rootHex, entropyHex, rule = "oomi-rules/0.3") {
  const seed = sha(Buffer.concat([lp("oomi:mutation:v1"), u32(epoch), lp(identity), Buffer.from(rootHex, "hex"), lp(rule), Buffer.from(entropyHex, "hex")]));
  const traits = {};
  TRAITS.forEach(([name, opts], i) => {
    const u = sha(Buffer.concat([seed, u32(i)])).readUInt32BE(0) / 2 ** 32;
    const total = opts.reduce((s, [, w]) => s + w, 0);
    let acc = 0;
    traits[name] = opts.find(([, w]) => (acc += w / total) > u)?.[0] ?? opts.at(-1)[0];
  });
  return { seed: seed.toString("hex"), traits };
}

const h = (t) => sha(Buffer.from(t)).toString("hex");
console.log(derive(7, "oomi:flagship", h("snapshot"), h("entropy")));