Z.ai confirms Ox Alpha is GLM-5.3 Flash, releasing weights tonight

Z.ai confirmed the stealth model Ox Alpha is GLM-5.3 Flash, with open weights releasing tonight. Priced at $0.15 per million input tokens and $0.50 output, it has 320B total parameters (18B active) and a 1M context window, approaching Opus 4.8 on coding benchmarks.