lucascs@protonmail.com Lucas C.S. jiter is a fast, iterable JSON parser written in Rust and exposed to Python through pyo3. Unlike the stdlib json module, it can parse a document incrementally and offers configurable handling of floats (float, Decimal or a lossless representation), duplicate keys and partial/incomplete input, which makes it suitable for consuming streaming JSON such as LLM responses. It is the JSON backend used by pydantic-core and the OpenAI Python client. https://github.com/pydantic/jiter/issues pydantic/jiter jiter