UUID v7

uuidv7.ts

// https://antonz.org/uuidv7/#javascript
export function uuidv7(): string {
  // random bytes
  const value = new Uint8Array(16);
  crypto.getRandomValues(value);

  // current timestamp in ms
  const timestamp = BigInt(Date.now());

  // timestamp
  value[0] = Number((timestamp >> 40n) & 0xffn);
  value[1] = Number((timestamp >> 32n) & 0xffn);
  value[2] = Number((timestamp >> 24n) & 0xffn);
  value[3] = Number((timestamp >> 16n) & 0xffn);
  value[4] = Number((timestamp >> 8n) & 0xffn);
  value[5] = Number(timestamp & 0xffn);

  // version and variant
  value[6] = (value[6] & 0x0f) | 0x70;
  value[8] = (value[8] & 0x3f) | 0x80;

  return Array.from(value)
    .map((b) => b.toString(16).padStart(2, "0"))
    .reduce((a, b, idx) => {
      if ([4, 6, 8, 10].includes(idx)) {
        return a + "-" + b;
      }
      return a + b;
    });
}

console.log(uuidv7());