Function read_frame 

pub fn read_frame(text: &str) -> String

The complete text of a read as the numbered frame Formal AI binds as a whole-file Read (#261): one NNNNN| line per \n-separated line and a trailer with the line count. Formal AI decodes it back to exactly text (lines joined with \n, so a missing or present final newline, CR bytes and Unicode survive); its OpenAI-compatible request parser drops any other metadata on a tool message, so the frame is the only binding it accepts.