Setup pstack

Write ~/.claude/pstack-models.md (under $CLAUDE_CONFIG_DIR instead of ~/.claude when that is set). pstack's SessionStart hook prints it into context at the start of every session, after /clear, and after compaction, so it acts as an always-applied rule. The skills fall back to their inline defaults when a line is absent, so this is an override layer, not a requirement.

Steps

1. Detect available models

Read the allowed values of the Agent tool's model parameter in this session; that is the dependable source, because it is exactly what a pstack skill can pass per call (typically opus, sonnet, haiku, and any newer alias the session lists). Never write a value you have not confirmed is in that set.

2. Load current state

The default role-to-model mapping is the file shape shown in step 5 below. If the config file 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 whose model is not in the detected set as needing a choice. Ask whether to accept as-is or change specific roles, offering the detected models as the options. Prefer AskUserQuestion over free text. For panel roles (how critics, arena runners, architect runners, interrogate reviewers) the value is a list, and one subagent runs per entry, so the list length sets the count. A model may repeat in a list; each entry is an independent sample.

Panels get their adversarial signal from diversity. With one model family, mixing tiers (opus, sonnet, haiku) gives more varied blind spots than repeating the top tier. Say so when the user collapses a panel to one model.

4. Validate

Every value written must be in the detected set. If a chosen value is not available, stop and ask again. A config pointing at a model the session cannot spawn breaks every delegation that reads it.

5. Write the config

Write the file with one line per role, using the same labels poteto-mode uses. Overwrite the whole file so re-runs stay idempotent. Shape:

# pstack model configuration. One line per role. Delete a line to fall back to the skill default.
feature, refactoring: sonnet
bug-fix, perf-issue: opus
judgment and prose: opus
how explorer: sonnet
how explainer: opus
how critics: opus, sonnet, haiku
why investigators: sonnet
why synthesizer: opus
reflect tooling: sonnet
reflect judgment, divergent, synthesizer: opus
arena runners: opus, sonnet, haiku
architect runners: opus, sonnet, haiku
interrogate reviewers: opus, sonnet, haiku

6. Confirm

Tell the user the file was written and that it loads in new sessions, or in this one after /clear. Re-running this skill updates it. Where hooks don't run (claude.ai chat), the skill defaults apply.