ardoise

Ardoise

Run Claude on a blank slate. The spawned Claude sees only its training weights and built-in skills — no CLAUDE.md, no custom skills, no hooks, no plugins, no project context. Like a restaurant's ardoise wiped clean.

Two modes:

• Interactive (default) — opens Claude's TUI as a fresh user would see it. For manual testing: plugin installs, onboarding flows, "what does a new user experience?"
• Print (-p) — runs claude -p for automated/scripted use. For surveys, evals, cold critique.

When to Use

• Plugin testing — does claude plugin install work for someone with a default ~/.claude?
• Design research — what verbs, patterns, or names would a Claude naturally produce?
• Skill evaluation — does a naive Claude understand a SKILL.md on first read?
• Eval baselines — "without skill" control group for A/B testing
• Isolation testing — verify a prompt works without your ecosystem's context
• Cold critique — get feedback uncoloured by your conventions

When NOT to Use

• Security sandboxing — this is context isolation, not filesystem/process isolation. The spawned Claude can still read host files if it knows the paths. Use containers for security.
• Testing your skills work — you want context loaded for that, not stripped

How It Works

Three mechanisms, all cross-platform (POSIX):

Mechanism	What it blocks
env -i	All inherited env vars including CLAUDECODE=1 (nesting detection)
HOME=<tmpdir> with stripped claude.json + credentials only	CLAUDE.md, settings.json, hooks, skills, plugins, MCP config
cd /tmp (or chosen dir)	Project CLAUDE.md, git repo context, local .claude/ directories

Additional env vars suppress noise:

Var	Effect
CLAUDE_CODE_DISABLE_FEEDBACK_SURVEY=1	No survey popups
CLAUDE_CODE_DISABLE_NONESSENTIAL_TRAFFIC=1	No telemetry
CLAUDE_CODE_DISABLE_AUTO_MEMORY=1	No auto memory files
ENABLE_CLAUDEAI_MCP_SERVERS=false	No built-in Gmail/Calendar MCP

The claude.json is copied from the real one (preserving onboarding state and feature flags) but stripped of project data, skill usage, and marketplace auto-install.

Usage

The script lives in the trousse plugin. Resolve the path:

SCRIPT="${CLAUDE_PLUGIN_ROOT}/scripts/ardoise.sh"
# Fallback if CLAUDE_PLUGIN_ROOT isn't set in the calling context:
[ -x "$SCRIPT" ] || SCRIPT=$(find ~/.claude/plugins/cache -path "*/trousse/*/scripts/ardoise.sh" 2>/dev/null | sort -r | head -1)

The fallback uses sort -r | head -1 to prefer the highest-versioned cached copy when multiple are present.

Interactive mode (default)

"$SCRIPT"                    # TUI in /tmp
"$SCRIPT" ~/some/project     # TUI in a specific directory

Opens Claude's interactive TUI. You type commands yourself — claude plugin install, /doctor, whatever you want to test manually.

Print mode

"$SCRIPT" -p "What is the best way to structure a CLI?"
"$SCRIPT" -p --max-turns 1 "Reply with only: hello"
echo "Design a work tracker" | "$SCRIPT" -p --stdin --max-turns 1

From Claude Code (OuterClaude calling InnerClaude)

# In a Bash tool call:
"$SCRIPT" -p --max-turns 1 "Your prompt here"

The env -i scrub removes CLAUDECODE=1, so the inner Claude doesn't know it's nested. No launch resistance.

What the Ardoise Claude Sees

Layer	Visible?
Global CLAUDE.md	No
Project CLAUDE.md	No
Custom skills (plugin cache)	No
Built-in skills (simplify, loop, claude-api)	Yes — compiled into Claude Code
Hooks	No
MCP servers	No
Plugins	No
Host filesystem	Yes — context isolation, not security sandboxing

Key Discovery: The ~/.claude.json Symlink

Claude Code reads config from $HOME/.claude.json (a symlink in HOME root), not directly from $HOME/.claude/claude.json. Without this symlink in the temp HOME, Claude treats every launch as brand new and shows the onboarding wizard. The script creates this symlink automatically.

Composing with Other Skills

Skill	How they compose
skill-forge	Eval baselines — run prompts without the skill for A/B comparison

Anti-Patterns

Anti-Pattern	Problem	Fix
Use Agent/Task tool for "naive" testing	Subagents inherit full parent context	Use this script via Bash tool
Pass --system-prompt and assume isolation	CLAUDE.md still loads	Use ardoise.sh
Use --allowed-tools "" for tool-free mode	Model burns turns trying tools	Pass --tools ""
Mount the real HOME	Context leaks	Let the script handle HOME
Forget the ~/.claude.json symlink	Onboarding wizard every time	Script handles this automatically