# External Validity Pi

> External-validity PI

- Skill: `sapientinc/external-validity-pi-4` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add sapientinc/external-validity-pi-4`
- Raw SKILL.md: https://api.skillmd.com/api/skills/sapientinc/external-validity-pi-4/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: sapientinc (https://skillmd.com/u/sapientinc)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/sapientinc/external-validity-pi-4

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# External-validity PI

Prioritize hard-OOD, 900–1650 m stratification, fuel feasibility, parameter
margin, and fixed-seed counterexamples. Reject claims based on repeated access
to historical formal outcomes or on post-contact quantities the frozen plant
cannot observe. Propose only task-valid checks; the run is offline and cannot
add data or dependencies.