UUID Version 7 Generator

// Browser / Node 22+ with Web Crypto
function generateUUIDv7(): string {
  const bytes = new Uint8Array(16);
  crypto.getRandomValues(bytes);
  const now = Date.now();

  bytes[0] = (now / 0x10000000000) & 0xff;
  bytes[1] = (now / 0x100000000) & 0xff;
  bytes[2] = (now / 0x1000000) & 0xff;
  bytes[3] = (now / 0x10000) & 0xff;
  bytes[4] = (now / 0x100) & 0xff;
  bytes[5] = now & 0xff;

  bytes[6] = (bytes[6] & 0x0f) | 0x70; // version 7
  bytes[8] = (bytes[8] & 0x3f) | 0x80; // variant

  return [...bytes].map((b, i) =>
    (i === 4 || i === 6 || i === 8 || i === 10 ? '-' : '') + b.toString(16).padStart(2, '0')
  ).join('');
}

import uuid6

new_id = uuid6.uuid7()
print(new_id) # e.g. 018e6a12-8921-71e4-8a4e-128a9b345678

-- PostgreSQL 13+ native UUIDv7 generator
CREATE OR REPLACE FUNCTION uuid_generate_v7()
RETURNS uuid AS $$
DECLARE
  v_time numeric = extract(epoch FROM clock_timestamp()) * 1000;
  v_bytes bytea = gen_random_bytes(16);
BEGIN
  v_bytes = set_byte(v_bytes, 0, (v_time::bigint >> 40)::int);
  v_bytes = set_byte(v_bytes, 1, (v_time::bigint >> 32)::int);
  v_bytes = set_byte(v_bytes, 2, (v_time::bigint >> 24)::int);
  v_bytes = set_byte(v_bytes, 3, (v_time::bigint >> 16)::int);
  v_bytes = set_byte(v_bytes, 4, (v_time::bigint >> 8)::int);
  v_bytes = set_byte(v_bytes, 5, (v_time::bigint)::int);
  v_bytes = set_byte(v_bytes, 6, (get_byte(v_bytes, 6) & 15) | 112);
  v_bytes = set_byte(v_bytes, 8, (get_byte(v_bytes, 8) & 63) | 128);
  RETURN encode(v_bytes, 'hex')::uuid;
END;
$$ LANGUAGE plpgsql VOLATILE;