Hello @ihssmaheel,
Thanks for the report. This is expected behavior with LLMs.
Unless the specific version string is hard-coded into the System Instruction, models often guess their identity based on their training data. Since ‘Sonnet 4’ and ‘Opus’ likely share similar underlying training datasets or alignment fine-tuning, the model may confuse its own persona.
I just asked the same question in my Antigravity setup and got answer “I’m Antigravity.”
As long as the Project Settings or Chat Dropdown shows ‘Claude Opus,’ the Antigravity backend is strictly enforcing that selection for your API calls.