#Api

If your code has a try/catch wrapped around a json_decode of the model's response, you don't have a contract. You have hope. How to get truly guaranteed structured output from an LLM: constrained decoding at the provider, a schema the model can satisfy, semantic validation and retry with a fixed budget, with no infinite loop and no defensive parser.

Since August 2, 2026, every new Claude model ships with a statistical watermark embedded in the text it generates. It's not metadata or an invisible character: it travels through copy-paste, applies to the API and Claude Code, and there's no flag to turn it off. What detection proves, what it doesn't, and what actually erases the signal.