Module spec_key 

2026-10-04: The plan digests that key a measured speculative-cost table (--spec-cost-model measured): per measured mode (verify, verify_batch, draft), one digest over every plan the recipe’s circuit instance declares for that mode, each verify/draft plan followed by its runtime-route arms, fused offline as met circuit show fuses them. The golden plans specify the kernel routing of the legacy forward too, so the key describes the kernels either forward runs; it needs no executor. met benchmark spec-cost-table writes it, and the serve recomputes it at boot and refuses a table whose key differs.

Owner: model-layers (circuit_exec). Invariants:

• A recipe without a circuit instance has no key: refused, never approximated.
• A measured mode for which the instance declares no plan is refused: its cost would be keyed by nothing that changes with its kernels.

Constants

KEY_MODES

2026-10-04: The modes a speculative step runs, in key order.

Functions

spec_cost_plan_digests

2026-10-04: Mode name → digest over that mode’s declared plans, for recipe.