From 27d9db44a0f1abe8a404224c5634ceab45b4279b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christopher=20M=C3=BChl?= <toki@toph.so>
Date: Thu, 9 Apr 2026 21:18:10 +0200
Subject: [PATCH] feat(03-01): add SANDBOX.md generation and CLAUDE.md import
 check

---
 claudebox.sh | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/claudebox.sh b/claudebox.sh
index 9ecd00e..5429ea3 100644
--- a/claudebox.sh
+++ b/claudebox.sh
@@ -101,6 +101,57 @@ CWD=$(pwd)
 # Ensure ~/.claudebox exists
 mkdir -p "$HOME/.claudebox"
 
+# === Sandbox-aware prompting (AWARE-01, AWARE-02) ===
+
+# Write SANDBOX.md -- fully managed, overwritten every launch (D-02)
+cat > "$HOME/.claudebox/SANDBOX.md" << 'SANDBOXEOF'
+# Sandbox Environment
+
+You are running inside a bubblewrap (bwrap) sandbox managed by claudebox.
+Your filesystem is isolated -- only the current working directory and
+essential system paths are mounted.
+
+## Installing Tools
+
+You have two ways to install tools on the fly:
+
+**Comma (preferred for quick one-off commands):**
+`, ripgrep` runs ripgrep without permanent installation. Comma uses
+nix-index to find the right package automatically.
+
+**Nix shell (for persistent access within the session):**
+`nix shell nixpkgs#python3 -c python3 script.py` runs a command with
+a package available. To keep it in your PATH for the session:
+`nix shell nixpkgs#python3` then use `python3` normally.
+
+## Default Restrictions
+
+By default, the following are not mounted into the sandbox:
+- SSH keys (~/.ssh)
+- GPG and age keys (~/.gnupg, age key files)
+- Cloud credentials (~/.aws, ~/.config/gcloud)
+- Tailscale state
+
+If your setup has been customized, some of these may be available.
+
+## Git
+
+Your git identity (name and email) is pre-configured from the host.
+The `safe.directory` setting trusts the mounted working directory.
+For remote operations, prefer HTTPS URLs over SSH since SSH keys
+are not available by default.
+SANDBOXEOF
+
+# Ensure CLAUDE.md has @SANDBOX.md import (D-03, D-08, AWARE-01)
+CLAUDEMD="$HOME/.claudebox/CLAUDE.md"
+if [[ ! -f "$CLAUDEMD" ]]; then
+  printf '%s\n' "@SANDBOX.md" > "$CLAUDEMD"
+elif [[ "$(head -1 "$CLAUDEMD")" != "@SANDBOX.md" ]]; then
+  tmp=$(mktemp)
+  { printf '%s\n' "@SANDBOX.md"; cat "$CLAUDEMD"; } > "$tmp"
+  mv "$tmp" "$CLAUDEMD"
+fi
+
 # Generate minimal .gitconfig (D-05)
 GIT_NAME=$(git config --global user.name 2>/dev/null || echo "Claude User")
 GIT_EMAIL=$(git config --global user.email 2>/dev/null || echo "claude@localhost")