OpenAI (Responses) and Anthropic (Messages) treat xhigh and max as
DISTINCT effort levels in 2026, and the Kimi K3 wire's top tier is max —
the old parse alias (max→Xhigh) conflated them. Canonical Max now exists:
parse/as_str/serde split, Messages mapping sends xhigh and max as their
own tokens (was Xhigh→"max"), and the K3 menu token max carries
canonical Max end to end.
Kimi wire is byte-identical in all four flows (menu pick, restored
legacy xhigh session, --reasoning-effort flag, /effort command) —
adversarially traced and pinned: kimi_compat's string-level xhigh→max
rename covers legacy tokens, max passes through verbatim.
From the review:
- Rollback safety: persisted reasoning_effort (session summaries, chat
history) deserializes leniently — unknown future tokens degrade to
None with a warning instead of hiding sessions or failing resume.
- Restore migration: a pre-split xhigh override onto a model whose menu
offers max but not xhigh (K3) migrates once, healing display/active-row
drift and re-persisting the live vocabulary.
- /effort max now rejects (with the offered list) on models whose menu
lacks a max row instead of silently applying xhigh; deliberate, tested.
- The interim Responses-backend Max→xhigh downgrade (async-openai has no
Max variant through 0.41) warns loudly; real max wiring lands with the
OpenAI provider cycle via post-serialize body patch.
- Two rusted ignored-e2e wire pins asserted the pre-adapt reasoning_effort
key (deleted by the body adapter since ea0ce9d); they now pin the real
thinking.effort=max shape.
ZacharyZhang-NY
83e6935189