Setup Jstack

---
name: setup-jstack
description: "Use when the user wants to configure Jstack's per-role Claude models."
license: MIT
metadata:
  author: jstack-maintainers
  source: michael-denyer/pstack-claude
  source-version: "0.9.30"
  source-commit: 45f768349a6d7d7e71509fee3f5bccfad54b3bad
  owner: software-factory
  risk: medium
  capabilities: jstack,engineering-workflow
---

# Setup Jstack

On Codex, Cursor, or another non-Claude runtime, read the [runtime mapping](../poteto-mode/references/harness-tools.md), 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:

```text
@~/.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](#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.

```markdown
# 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`