It called it "Spark Copilot", and it works similarly to the real thing.
Its transcript format and per-session token usage are not a supported public interface, so the adapter records needed hook events locally and reports session cost as unavailable. Cursor support is ...
For text files over 400 lines, it denies whole reads and sections larger than 400 lines, with a suggestion to search with rg -n and read a bounded section. A small file can still be read whole.