OpenRouter listed Ox Alpha as stealth/ox-alpha — a 1M-context, multimodal, tool-calling model at $0/$0 that quickly became the platform's #1 model, more than doubling DeepSeek usage. Community forensics (tokenizer match to GLM-5.3, Z.AI error code 1214, Java stack trace) identified Zhipu before the lab spoke. On August 26, 2026, Z.AI confirmed to Bloomberg News that Ox Alpha is a new GLM iteration, then named it GLM-5.3-Flash that evening with MIT weights at huggingface.co/zai-org/GLM-5.3-Flash and API pricing of $0.15/$0.50 per million tokens.