Files
turnstone/tests
Patrick Buckley 2fb80cb88f fix(compaction): count fixed prompt overhead in the carry budget
Review finding on #751: the carry invariant omitted the system message
and tool definitions, which ride every request — at shipped defaults
reserve + 2 carries + margin lands exactly at the window, so any real
prompt overhead pushed the post-compaction send over it, and the
overflow backstop re-compacts WITHOUT the carries.

spare now subtracts system_tokens + tool_def_tokens (the same terms the
_estimated_prompt_tokens fallback counts), making
overhead + reserve + carries*budget + margin <= window hold by
construction. Invariant test pinned at shipped defaults with a 4k-token
synthetic prompt; a monotonicity test pins that the term is live; exact-
arithmetic tests isolate the overhead explicitly.
2026-07-01 21:06:31 -07:00
..