Setup Jstack

On Codex, Cursor, or another non-Claude runtime, read the runtime mapping, including its per-skill notes, before following this skill.

Write ~/.claude/jstack-models.md, a per-role model override sheet you include from your global CLAUDE.md. Each Jstack skill names a default model inline; the override sheet is the layer that adapts those defaults to the models you actually have access to.

Claude Code has no auto-applied "rules" mechanism like Cursor's .mdc. Inclusion is explicit: the user adds a line to ~/.claude/CLAUDE.md (or their project CLAUDE.md) such as:

@~/.claude/jstack-models.md

so the file is loaded as context for every session.

Steps

1. Detect available models

Enumerate the model slugs you can pass to an Agent subagent in this session — that is the dependable source. The currently available Claude models and the default panel are listed in Models below; the quad is chosen for cross-family, cross-tier diversity, and the single-role default stays out of the panels because it already covers the single-model roles. Ask the user to confirm or paste any additional slugs they want available. Never write a real slug you have not confirmed is available. The aliases inherit-parent and auto are always valid even though they are not detected slugs; both mean the role runs on the parent session's model, which the Agent call expresses by omitting model.

2. Load current state

The default role-to-model mapping is the rule shape shown in step 5 below. If ~/.claude/jstack-models.md already exists, read it and treat its values as the current choices. Otherwise start from those defaults.

3. Map and confirm

Show every role with its current model, marking any real slug not in the detected set as needing a choice. Ask whether to accept as-is or change specific roles, offering the detected models plus inherit-parent and auto as the options. Prefer AskUserQuestion over free text. For panel roles (arena runners, architect runners, interrogate reviewers) the value is a list, and one subagent runs per entry, alias entries included, so the list length sets the count. arena cross-judge pool is also a list, but Arena selects one value from it whose model family differs from the parent's when possible. swarm workers is the default model for every worker unless a race or comparison assigns another model per arm.

4. Validate

Every real slug written must be in the detected set; inherit-parent and auto always pass. If a chosen real slug is not available, stop and ask again.

5. Write the override sheet

Write ~/.claude/jstack-models.md with the shape below. Overwrite the whole file so re-runs stay idempotent.

# Jstack model configuration

Per-role model overrides for Jstack skills. Each Jstack SKILL.md names its defaults in a Models section; the values here override those defaults. Delete a line to fall back to the skill default. A value of `inherit-parent` or `auto` runs that role on the parent session's model (the `Agent` call omits `model`); an alias entry in a panel list still counts toward that panel's fan-out.

feature, refactoring: claude-opus-5
bug-fix: claude-fable-5-1
perf-issue: claude-fable-5-1
hillclimb: claude-fable-5-1
judgment and prose: claude-opus-5
strongest judgment: claude-fable-5-1
how explorer: claude-opus-5
how explainer: claude-opus-5
why investigators: claude-opus-5
why synthesizer: claude-opus-5
reflect tooling: claude-opus-5
reflect judgment, divergent, synthesizer: claude-opus-5
arena runners: claude-opus-5, claude-fable-5-1, claude-sonnet-5
arena cross-judge pool: claude-opus-5, claude-fable-5-1, claude-sonnet-5
swarm workers: claude-opus-5
architect runners: claude-opus-5, claude-fable-5-1, claude-sonnet-5
interrogate reviewers: claude-opus-5, claude-fable-5-1, claude-sonnet-5

6. Wire it in

If ~/.claude/CLAUDE.md does not already include ~/.claude/jstack-models.md, append the @~/.claude/jstack-models.md line so it loads on every session. If the user prefers project scope, add the include to the project's CLAUDE.md instead.

7. Confirm

Tell the user where the override was written and how it loads (via the @ include in CLAUDE.md). Re-running this skill updates the override sheet.

Models

Defaults originate from the upstream plugins/pstack/models.json. Refresh them through scripts/vendor_jstack.py after reviewing the upstream change.

• Available Claude models: Opus 5 (claude-opus-5), Opus 4.8 (claude-opus-4-8), Opus 4.6 (claude-opus-4-6), Fable 5.1 (claude-fable-5-1), Sonnet 5 (claude-sonnet-5), Sonnet 4.6 (claude-sonnet-4-6), Haiku 4.5 (claude-haiku-4-5)
• Default panel: claude-opus-5, claude-fable-5-1, claude-sonnet-5
• Single-role default: claude-opus-5