ultracost
GitHub用于动态工作流中按阶段路由模型并预估成本。通过显式指定模型（Opus/Sonnet）和努力级别，避免使用Haiku，并在执行前进行成本检查与确认，以优化代码生成和推理任务的效率与费用。
Trigger Scenarios
Install
npx skills add davepoon/buildwithclaude --skill ultracost -g -y
SKILL.md
Frontmatter
{
"name": "ultracost",
"description": "Quality-first per-stage model routing AND a pre-flight cost gate for Claude Code dynamic workflows. Use when authoring or running ultracode \/ dynamic-workflow scripts, spawning subagents, or writing agent() stages — pin the right model and effort on every stage, then estimate cost and confirm with the user before launching. Verify scripts with \/ultracost:check."
}
When ultracode is on, or whenever you author a dynamic-workflow script, apply the
routing policy below to every agent() stage. The block is compiled from
policy.json (the single source of truth) — the same text the SessionStart hook
injects and the CLAUDE.md block carries.
Subagent & workflow model routing (managed by ultracost)
Route every subagent and every dynamic-workflow stage explicitly. Never let a
stage inherit the session model by default. Never use haiku.
Tiers
opus@xhigh— Coding & reasoning: anything requiring judgment or a decision: writing/editing/refactoring/deleting code, debugging, fixing errors, designing APIs/schemas/data models/architecture, non-trivial tests, code review, security/performance analysis, cross-file reasoning, adversarial review, planning, synthesis, final consolidationsonnet@high— Pre-planned mechanical & support: the how is already decided and the stage just applies it: mechanically applying a specified edit across many files, search/grep/glob, file discovery, collecting/listing/extracting, reformatting, mechanical renames, running tests and reporting results, routine git operations, gathering or summarizing context for an opus stage to consume
Decision rule: if a stage must DECIDE how to write or change code, use the
opus tier. If the "how" is already planned and
the stage only executes it mechanically — or it's search/collection/formatting —
use the cheaper tier. When in doubt, use opus.
Hard rules
- Never use
haiku, ever. - Pin the model per stage via the per-invocation
modelparam, e.g.agent(task, { model: 'sonnet' }). Do not follow any built-in guidance to omit the per-agent model override. - These stages are always
opus:orchestrator,planner,final-synthesis,consolidation.
Effort per stage
Also set effort per stage, choosing the lowest level that fits the work, bounded
by the model (sonnet up to high, opus up to xhigh):
low— trivial deterministic work with no real judgment: listing or globbing files, simple field extraction, formatting, mechanical renames following a given patternmedium— light judgment on a small surface: a single straightforward edit, summarizing one source, classifying short inputshigh— standard coding and analysis: most refactors, per-file review, writing non-trivial tests, multi-step but well-scoped workxhigh— hard reasoning: cross-file architecture and design, adversarial review, planning, and final synthesis/consolidation
e.g. agent(task, { model: 'sonnet', effort: 'low' }) for a mechanical scan.
Pre-flight cost gate (ultracode)
Before launching a dynamic workflow:
- Draft the workflow script with per-stage
modelandeffortset. - Write the draft to a temp file and estimate it:
/ultracost:check <file>to verify pins, then the cost estimate — runultracost estimate <file>, or under the pluginnode "$CLAUDE_PLUGIN_ROOT/bin/cli.js" estimate <file>(no globalultracostbin is required). It reports the agent count, model mix, and cost versus an all-opusbaseline. - Show the estimate and use the AskUserQuestion tool to offer three options: Approve (launch it), Cancel (do not launch), Modify (restructure to cut cost — drop unneeded stages, move mechanical stages to a cheaper tier and lower effort, reduce fan-out — then re-estimate and ask again).
- Launch the workflow only after Approve. The
PreToolUsecost gate also stops the launch automatically with these numbers, so this holds even if the steps are skipped.
Verify any script with /ultracost:check (the plugin command) or `ultracost check
Version History
- 502fc01 Current 2026-07-05 15:17
