---
title: "Decision: active-platform skill"
type: concept
updated: 2026-04-28
---

# Decision: `active-platform` skill

_2026-04-28._

## Problem

The user develops on multiple machines (Windows primary, Linux/macOS secondary). I was generating bash one-liners by default — wrong shell for their daily workstation. Need a way to make Windows/PowerShell the default and switch on a phrase.

## Options weighed

- **Project memory** — wrong scope (project-only, doesn't cross repos).
- **Global `~/.claude/CLAUDE.md`** — right scope, simple, but the user explicitly preferred a skill: "поживём со скиллом" (let's live with a skill and iterate).
- **New skill** ← chosen.

The user's reasoning for the skill route: it's a discoverable, shareable artifact that lives next to their other 12 skills, and it can evolve with the same edit/build/install loop.

## What the skill does

Switches command/example generation between Windows / Linux / macOS based on session signals. Default = Windows + PowerShell. Trigger phrases in RU + EN (e.g. "мы на винде", "we're on Linux"). The rule applies only to **user-facing output** — tool calls still follow the harness's `Shell:` line.

Full spec: [`skills/active-platform/SKILL.md`](../../skills/active-platform/SKILL.md).

## Why this is a skill, not memory

- **Discoverability:** appears in `available_skills` list, can be re-read or audited.
- **Cross-repo:** installed into `~/.claude/skills/`, applies in every session regardless of project.
- **Iterable:** lives in this repo's `skills/` so we can edit + reinstall as we learn what triggers and exceptions actually happen in practice.

## Wired into `project-bootstrap`

The default platform should travel with every new project we create. Updated `project-bootstrap` so its `CLAUDE.md.template` adds a fifth trigger line: `we're on Windows`. That line is one of `active-platform`'s recognized switches, so any project bootstrapped from now on starts pinned to Windows / PowerShell. If the user is bootstrapping on a Linux/macOS host, the `SKILL.md` Step 5 note tells them to swap the line for `we're on Linux` / `we're on macOS`.

Backfilled the same line into this repo's own `CLAUDE.md` (which was created from the old template).

## Open questions to revisit

- Are the trigger phrases comprehensive enough? Add real-world examples as they come up.
- WSL handling — currently treated as Linux. Reconsider if user has WSL-specific needs.
- macOS divergences (BSD coreutils, Homebrew) — minimal coverage now, expand if user actually uses macOS often.