While the SDK supports streaming for various message blocks (e.g., tool usage/result, system message, result message, text message etc.), TextBlock content is only delivered once it's fully available. This delays rendering for long messages, even if TTFT is low. Supporting partial streaming of TextBlock content would let applications render text incrementally, improving user experience a lot.

In current streaming guide, we receive entire block at once:

https://github.com/anthropics/claude-code-sdk-python/blob/3010aaf092186a24dae240d78f0ee7d2e0d5d62a/examples/streaming_mode_ipython.py#L26