efficient-dispatch

efficient-dispatch - routed, measured, verified

The main model is the orchestrator and Q&A reviewer. Mechanical work runs on cheaper models - and unlike guidance-only approaches, every claim here is checkable against your own ax graph.

The split

Two axes. First, main model vs subagent: the main model orchestrates and reviews; mechanical work goes to subagents. Second, and the one that actually controls spend - the tier of each subagent dispatch:

• Implementer subagents (well-specified plan tasks, mechanical edits, search, bulk transforms) → dispatch with model: sonnet (or haiku for pure search/locate, per the table).
• Reviewer / judgment subagents (quality / PR / final / adversarial / code review, design, audit, architect, critique, judge) → keep the strong model: inherit the main model, or set model: opus/fable explicitly. Review is the catch-rate gate; a cheap reviewer misses real bugs.

Get this backwards and you pay twice: in one ax session implementers ran on the expensive inherited model while reviewers were sent to a cheap one - ~$130 over, weaker catch rate, three fix rounds (memory feedback-review-gets-strong-model). The default-inherit trap is implementers, not reviewers: a forgotten model: on an implement … dispatch silently runs expensive. Set it.

Main model keeps (never dispatched at all): decomposition, architecture and product tradeoffs, plan synthesis, judging conflicting subagent reports, final integration, taste-heavy design/copy.

Routing table

Source of truth: ~/.ax/hooks/routing-table.json (regenerate with ax dispatches compile-routing). Consult it when present; these built-ins mirror it:

class	description pattern	model
spec-review	^spec review	sonnet
search-locate	^(pattern-find|locate|find|map|sweep|grep)	haiku
research	^(research|investigate docs|study)	sonnet
well-specified-impl	^implement	sonnet
bulk-mechanical	^(write announcements|regenerate|standardize|merge main)	sonnet
task-N-impl	^Task \d+:	sonnet
bug-fix	^Fix\s	sonnet
feature-add	^Add\s	sonnet
agent types	Explore, codebase-locator, codebase-pattern-finder → haiku; codebase-analyzer → sonnet

Anything unmatched: leave the model unset only if the work genuinely needs main-model judgment - otherwise pick sonnet.

Dispatch discipline

1. Decompose into independent slices BEFORE reading everything yourself; run slices as parallel subagents in isolated worktrees when they edit files.
2. Every brief is self-contained: repo path, exact objective, in/out of scope, evidence format to return (files, line refs, commands, diffs, failures), verification commands, stop conditions.
3. Set model: explicitly on every mechanical dispatch. The route-dispatch hook is quota-aware and ADVISORY (Claude Code hooks cannot enforce model on subagent dispatches - they can only inject context via additionalContext): in conserve mode it advises re-dispatching a forgotten mechanical dispatch with model:<cheaper>; near a 7d quota reset (splurge) it stays quiet so work runs on the strong inherited model; it advises when judgment work (review/design/audit) is sent on a cheap model. Real enforcement is your discipline + setting model: explicitly on every dispatch. Treat the advisory as a re-dispatch signal, not noise.
4. Workflow scripts (.claude/workflows/*.js) run sandboxed and cannot import ax code. Set model: on every agent(...) call by hand, per ax routing show: mechanical stages → model: 'sonnet'; judgment/review stages → keep the strong model. routing-tune.workflow.js is the reference. In-tree Effect/axctl code that dispatches should call resolveDispatchModel (from @ax/hooks-sdk) instead of hardcoding.
5. Treat subagent reports as leads. Before acting on a high-impact finding or declaring done, reopen the cited files and re-run the key verification yourself. Expect to find one real bug per delegated phase.

Measure (what guidance-only skills can't do)

• ax dispatches --days=7 - your inherit rate (target: explicit model on all mechanical classes)
• ax dispatches --candidates - missed routings + est savings, repriced from real token buckets
• ax cost split --days=7 - main vs subagent spend by model; the dominant cost is usually main-loop cache reads, so move tool-heavy loops (build/test cycles, browser QA) into subagents entirely
• ax improve recommend - surfaces a routing proposal automatically when missed savings accumulate

Verify

After adopting this skill, compare windows: ax cost split + inherit rate before vs after. If the inherit rate doesn't drop, the routing isn't happening - check ax hooks backtest ~/.ax/hooks/route-dispatch.ts --days=7 and whether dispatches are bypassing the table.