Model Classifier

One task description goes in, one model recommendation + a one-line reason comes out. This exists so model-selection decisions (which model builds/reviews/designs a given piece of work) are made the same way every time, instead of re-litigated per task or per mood.

This skill names models, not harnesses. "Model" is the underlying AI (GPT-5.5 Codex, Claude Opus 4.8, Kimi K2.7 Code, ...); "harness" is whatever CLI/wrapper/API call actually invokes it (Claude Code, Codex CLI, agy, a shell wrapper, a raw API call). Which harness to use is the caller's decision, made separately — often the same model is reachable through more than one harness, and that mapping changes over time. Answer with the model only.

The lineup

Reading the scale

Every rating is 1–9, and higher is always better on that axis — including cost:

So a cost of 9 means very cheap, not very costly — think of every number as "how much do you want this," never "how much does it hurt." Cost ranks real per-token price across providers (Kimi/GLM cheapest, Gemini slightly dearer, GPT dearer still, Fable dearest), tempered by which quota it draws from.

The table

⚠️ = estimated, not yet field-validated. The Claude rows and GPT-5.5 (Codex) numbers are hand-tuned from lived experience (cost spread to follow real price ordering). GLM-5.2, Kimi K2.7 Code, and both Gemini rows are best-guess placements from public benchmarks and pricing, not lived experience — treat them as a starting point and correct them (or ask to correct them) the first time a real task proves one wrong in either direction.

Model-name notes, so recommendations stay unambiguous:

• GPT-5.5 (Codex) = OpenAI's 5.5-generation coding model (the thing the Codex CLI runs). Say "GPT-5.5 (Codex)"; the caller picks how to reach it.
• Grok 4.5 = xAI's fast, very capable frontier model. In Pi it is reachable via xai-auth/grok-4.5 or OpenRouter x-ai/grok-4.5; prefer the direct xAI route when available. Treat it as a cheap Fable-adjacent model until field data says otherwise.
• GPT-5.6 Luna / Sol / Terra = OpenAI 5.6 family models available in Pi via openai-codex and OpenRouter. Treat them as Fable-tier reasoning/design options on OpenAI/Codex/OpenRouter quota. Default interpretation: Luna = broad high-taste generalist, Sol = hard reasoning/coding, Terra = strongest taste/product/design.
• Kimi K2.7 Code is Moonshot's coding flagship; a "highspeed" serving tier of the same model exists — that's a harness/serving choice, not a different recommendation.
• GLM-5.2 is Z.ai's flagship (1M context — the only non-Claude, non-GPT row with one).

Why these three axes, and how they interact

• Intelligence — how hard a problem you can hand this model unsupervised and trust the result. This is the main lever for anything genuinely difficult: novel architecture, ambiguous requirements, security/money-logic reasoning, debugging something nobody's seen before.
• Taste — UI/UX judgment, code quality, API design sense, copywriting. A model can be highly intelligent and still make ugly, over-engineered, or tone-deaf choices — taste is a separate skill from raw reasoning power, and it's the axis that decides whether end users or teammates will notice the output was AI-assisted.
• Cost — a tie-breaker, not a veto. When two models would both do the job well, prefer the cheaper one. When they disagree — i.e. the cheap model is measurably less capable — the priority order is intelligence > taste > cost. Never let cost talk you into a model that can't actually do the job; escalating to a pricier model costs less than shipping mediocre or broken work and redoing it.

These are defaults, not hard limits. If a cheaper model's output doesn't clear the bar, rerun or redo the work on a smarter model without asking — judge the output you got, not the price tag you expected to pay.

Decision procedure

Read the task description and place it into whichever of these fits best. They're ordered roughly cheapest-first because that's the instinct to check first, not because you should default there — go through them in order and stop at the first real match.

1. Trivial / mechanical / known-answer — renames, boilerplate, running a frozen regression checklist, simple greps, anything where the "right answer" is already fully determined and there's nothing to judge. → Claude Haiku 4.5 (cost 9, and intelligence 2 is plenty when there's nothing to reason about). If Haiku isn't available in this context, GLM-5.2 or Gemini 3.5 Flash are the cheap fallbacks.
2. Bulk / mechanical with a clear spec — implementation where the ticket already fully specifies behavior, data-processing/migration scripts, repetitive multi-file changes that follow one pattern. Needs real intelligence to execute correctly but no taste calls. → Kimi K2.7 Code or GLM-5.2 (cost 9, intelligence 7 comfortably covers specced work — pick either; alternating between them is free provider diversity). For the trickiest items in a batch, or when the work is subtle enough that intelligence 7 feels marginal, step up to GPT-5.5 (Codex), Grok 4.5, GPT-5.6 Sol, or Gemini 3.1 Pro: prefer GPT-5.5 (Codex) for standard hands-on coding, Grok 4.5 when you need a fast/cheap frontier pass, GPT-5.6 Sol when intelligence 8 feels marginal, and Gemini 3.1 Pro for analysis, long-context reading, or when the OpenAI/xAI sides are saturated.
3. User-facing — UI, copy, API/product design — anything an end user or another engineer will read, look at, or call. This is a hard filter, not just a preference: taste must be ≥ 7, because a low-taste model will produce something that visibly reads as under-designed no matter how "correct" it is. Under the table above that filter currently clears Claude Sonnet 5 (7), Claude Opus 4.8 (8), Claude Fable 5 (9), Grok 4.5 (8), and GPT-5.6 Luna/Sol/Terra (8/8/9). Within that shortlist, apply intelligence > taste > cost: simple polish or small UI tasks → Sonnet 5; standard-to-complex design/API work → Grok 4.5, GPT-5.6 Luna/Terra, or Opus 4.8; genuinely novel or high-stakes design (new product surface, pricing page, something that sets a pattern others will copy) → Claude Fable 5 or GPT-5.6 Terra.
4. Review of a plan or implementation — judging someone else's design doc or PR, not producing new work. → Claude Opus 4.8 as the default reviewer (intelligence 8 is what a good review needs, at a fraction of Fable's cost). Escalate to Claude Fable 5 only when the thing under review is itself high-stakes by the same bar as #5 — security models, money-logic, architecture, something expensive and hard to detect if wrong (e.g. reviewing a payment-webhook signature check, not a routine UI PR). Optionally add GPT-5.5 (Codex) or Gemini 3.1 Pro as a second, genuinely independent pass on either tier — not as a cost-saving substitute, but because a different model family catches different mistakes than whichever family wrote the thing being reviewed.
5. Hardest reasoning / high-stakes judgment — new architecture, security models, money-logic design, postmortems, or anything where being wrong is expensive and hard to detect after the fact. → Claude Fable 5, GPT-5.6 Terra/Sol, or Grok 4.5. Fable remains the conservative gold standard; GPT-5.6 Terra/Sol are Fable-tier OpenAI options; Grok 4.5 is the cheap/fast frontier option. Use these as escalations, not residents: get the specific answer, don't leave them running the rest of the task.
6. Everything else — standard, routine work — the bulk of day-to-day implementation, merges, everyday coding, most reviews that aren't covered by #4. → Claude Sonnet 5, the default workhorse (cost 5, intelligence 5 and taste 7 cover routine work well). If the task turns out to need more reasoning than expected, where you escalate depends on whether taste is in play: purely non-user-facing implementation complexity (algorithms, backend logic, no design calls) steps up to GPT-5.5 (Codex) or Gemini 3.1 Pro — the same intelligence 8 as Opus at better cost, per the #2 step-up tier — while work that also carries taste weight (code another engineer will study as a pattern, API surfaces, anything user-visible) moves up to Claude Opus 4.8 instead. This is a deliberate call: don't pay Opus prices for intelligence alone.

If a task spans categories (e.g. "implement this well-specified feature AND make the UI look good"), split it: route the mechanical parts by #2 and the taste-sensitive parts by #3, or if it can't be split, classify by whichever axis is the actual risk — if the UI is the part that will get noticed, treat the whole thing as user-facing.

Output format

Respond with just the model name and a one-line reason, e.g.:

Claude Opus 4.8 — user-facing settings redesign needs taste ≥ 7; standard-complexity design work, not novel enough to justify Fable.

Kimi K2.7 Code — fully-specified CSV export migration, no taste calls, cheapest capable model handles it.

Claude Haiku 4.5 — running the frozen regression checklist against known answers.

Name the model, never a harness/CLI/wrapper (not "Codex CLI," not "agy," not "claudekimi/claudeglm," not "Claude Code" — "GPT-5.5 (Codex)" is fine because that names the model itself). Don't pad this with a table walkthrough or restate the whole decision procedure — the point is a fast, confident answer the caller (often something about to delegate a piece of work to a subagent) can act on immediately, and route to whichever harness it has on hand for that model.

Delegating several tasks at once

This skill answers "what's the best model for this task" in isolation. If you're delegating multiple parallel tasks and they land on the same recommendation, that's fine on correctness grounds — but consider spreading them across different providers/quotas anyway (Anthropic vs OpenAI vs Google vs Moonshot vs Z.ai) so one rate limit doesn't stall the whole batch. Kimi K2.7 Code and GLM-5.2 being rating-identical makes them natural load-spreading partners. That's a scheduling and harness-selection concern layered on top of this skill's answer, not a reason to override it.

Keeping this current

The ⚠️-marked rows (GLM-5.2, Kimi K2.7 Code, Gemini 3.1 Pro, Gemini 3.5 Flash, Grok 4.5, GPT-5.6 Luna/Sol/Terra) are the ones most likely to need correcting — update their cost/intelligence/taste numbers directly in the table above the first time a real task shows one of them over- or under-performing its rating. The field-tuned rows (GPT-5.5 (Codex), Sonnet 5, Opus 4.8, Fable 5, Haiku 4.5) shouldn't drift without a deliberate change. When a provider ships a new generation (e.g. Kimi K2.8, GLM-5.3, a real Gemini 3.5 Pro), replace the old row rather than appending — one row per provider tier keeps the decision procedure unambiguous.