| name | route |
| description | Show the model-routing decision for a task (Fable/Opus/Sonnet/Haiku) with reasoning. Use before launching a packet to sanity-check the tier and to override when you have stronger judgment than the heuristic. |
/route — model routing decision
Surface the routing decision so the human (or the orchestrator) can confirm or override.
Default table
| Class | Tier | Reason |
|---|
| plan | Fable 5 while included (→2026-06-22), else Opus | decomposition quality propagates downstream |
| architect, spec | Opus | reasoning + spec authorship (pinned) |
| verify, audit | Opus | independent skepticism |
| debug-hard | Opus | subtle, multi-cause |
| implement, refactor, test | Sonnet | routine coding, fast and capable |
| search, summarize, classify, route | Haiku | cheap throughput |
Escalation triggers (Sonnet → Opus)
- complexity ≥ 7
- novelty ≥ 8 (no prior memory match)
- prior failure on similar packet
- security/auth/payments/secrets domain
- explicit
--tier opus or --opus user signal
Fable 5 routing (access-gated, auto-switch 2026-06-23)
Fable 5 (claude-fable-5, launched 2026-06-09, 2× Opus price) runs in two configurations via resolveFableAccess() (CMAX_FABLE_ACCESS=included|credits overrides):
- included (now → 2026-06-22, free on Max):
plan baselines to Fable; multispec decompose runs on Fable; --long-horizon escalates plan/debug-hard (overnight runs, multi-day converge loops, ambiguous root-cause hunts)
- credits (2026-06-23 →, bills usage credits): all Fable defaults auto-demote to Opus; only explicit
--tier fable / cmax loop run --fable reaches Fable
- in BOTH: NEVER for security domains (clamps to Opus — Fable's safety classifiers fall back there anyway; headless requests end the turn) and NEVER for
verify/spec/architect (pinned to Opus)
Demotion triggers (Fable/Opus → cheaper)
--cheap / forceCheap mode AND class is not verify or spec → Sonnet- plan-budget guard demotes one rung (fable→opus, opus→sonnet); danger/blocked → Sonnet
- cost ceiling exceeded AND a cheaper tier fits AND class is not
verify or spec (fable tries opus first, then sonnet)
Never demote
verify and spec always run on Opus. They are the supervisor and the contract — cheap them and the whole harness loses its teeth.
Output
Tier, model id, tools, maxTurns, estimated cost USD, escalation flag, reasoning. Pure read-only — no side effects.
