Adds a per-model behavioral patch layer orthogonal to the host axis.
Different LLMs have different tendencies (GPT won't stop, Gemini
over-explains, o-series wants structured output). Overlays nudge each
model toward better defaults for gstack workflows.
Codex review caught three landmines the prior reviews missed:
1. Host != model — Claude Code can run any Claude model, Codex runs
GPT/o-series, Cursor fronts multiple providers. Auto-detecting from
host would lie. Dropped auto-detect. --model is explicit (default
claude). Missing overlay file → empty string (graceful).
2. Import cycle — putting Model in resolvers/types.ts would cycle
through hosts/index. Created neutral scripts/models.ts instead.
3. "Final say" is dangerous — overlay at the end of preamble could
override STOP points, AskUserQuestion gates, /ship review gates.
Placed overlay after spawned-session-check but before voice + tier
sections. Wrapper heading adds explicit subordination language on
every overlay: "subordinate to skill workflow, STOP points,
AskUserQuestion gates, plan-mode safety, and /ship review gates."
Changes:
- scripts/models.ts: new neutral module. ALL_MODEL_NAMES, Model type,
resolveModel() for family heuristics (gpt-5.4-mini → gpt-5.4, o3 →
o-series, claude-opus-4-7 → claude), validateModel() helper.
- scripts/resolvers/types.ts: import Model, add ctx.model field.
- scripts/resolvers/model-overlay.ts: new resolver. Reads
model-overlays/{model}.md. Supports {{INHERIT:base}} directive at
top of file for concat (gpt-5.4 inherits gpt). Cycle guard.
- scripts/resolvers/index.ts: register MODEL_OVERLAY resolver.
- scripts/resolvers/preamble.ts: wire generateModelOverlay into
composition before voice. Print MODEL_OVERLAY: {model} in preamble
bash so users can see which overlay is active. Filter empty sections.
- scripts/gen-skill-docs.ts: parse --model CLI flag. Default claude.
Unknown model → throw with list of valid options.
- model-overlays/{claude,gpt,gpt-5.4,gemini,o-series}.md: behavioral
patches per model family. gpt-5.4.md uses {{INHERIT:gpt}} to extend
gpt.md without duplication.
- test/gen-skill-docs.test.ts: fix qa-only guardrail regex scope.
Was matching Edit/Glob/Grep anywhere after `allowed-tools:` in the
whole file. Now scoped to frontmatter only. Body prose (Claude
overlay references Edit as a tool) correctly no longer breaks it.
Verification:
- bun run gen:skill-docs --host all --dry-run → all fresh
- bun run gen:skill-docs --model gpt-5.4 → concat works, gpt.md +
gpt-5.4.md content appears in order
- bun run gen:skill-docs --model unknown → errors with valid list
- All generated skills contain MODEL_OVERLAY: claude in preamble
- Golden ship fixtures regenerated
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Garry Tan