---
phase: 03-sandbox-aware-prompting
verified: 2026-04-09T21:30:00Z
status: passed
score: 4/4
overrides_applied: 0
---

# Phase 3: Sandbox-Aware Prompting Verification Report

**Phase Goal:** Claude inside the sandbox knows it is sandboxed, how to install tools, and what is unavailable
**Verified:** 2026-04-09T21:30:00Z
**Status:** passed
**Re-verification:** No -- initial verification

## Goal Achievement

### Observable Truths

| # | Truth | Status | Evidence |
|---|-------|--------|----------|
| 1 | Claude inside the sandbox sees SANDBOX.md content describing its environment | VERIFIED | SANDBOX.md heredoc in claudebox.sh (lines 107-143) contains all 4 sections: Sandbox Environment, Installing Tools, Default Restrictions, Git. Bind mount at line 345 maps ~/.claudebox to ~/.claude inside sandbox. |
| 2 | CLAUDE.md in ~/.claudebox/ exists after first launch with @SANDBOX.md import on line 1 | VERIFIED | Lines 146-153: creates file with `@SANDBOX.md` if missing, prepends if first line differs. Behavioral test confirmed: first-run creates CLAUDE.md with exactly `@SANDBOX.md`. |
| 3 | SANDBOX.md is overwritten on every launch with current content | VERIFIED | `cat >` (line 107) unconditionally writes the file on every invocation. No conditional guard -- always overwrites. |
| 4 | Existing user content in CLAUDE.md is preserved when import line is prepended | VERIFIED | Lines 150-152: mktemp + printf + cat + mv pattern preserves existing content. Behavioral test confirmed: user content "# My custom stuff" preserved on line 2 after prepend. |

**Score:** 4/4 truths verified

### Required Artifacts

| Artifact | Expected | Status | Details |
|----------|----------|--------|---------|
| `claudebox.sh` | SANDBOX.md generation and CLAUDE.md import check | VERIFIED | Lines 104-153 contain the full implementation with section comment, heredoc, and import management |
| `~/.claudebox/SANDBOX.md` | Sandbox context for Claude Code | VERIFIED | Generated at runtime; confirmed via dry-run. Contains "bubblewrap" (line 110) |
| `~/.claudebox/CLAUDE.md` | User-owned CLAUDE.md with managed import | VERIFIED | Generated at runtime; confirmed via dry-run. Contains "@SANDBOX.md" on line 1 |

### Key Link Verification

| From | To | Via | Status | Details |
|------|----|-----|--------|---------|
| claudebox.sh | ~/.claudebox/SANDBOX.md | heredoc write on every launch | WIRED | `cat > "$HOME/.claudebox/SANDBOX.md" << 'SANDBOXEOF'` at line 107 |
| ~/.claudebox/CLAUDE.md | ~/.claudebox/SANDBOX.md | @SANDBOX.md import on line 1 | WIRED | `printf '%s\n' "@SANDBOX.md"` at lines 148/151 |
| bwrap --bind ~/.claudebox ~/.claude | Claude Code session | bind mount | WIRED | `--bind "$HOME/.claudebox" "$HOME/.claude"` at line 345 (exec) and line 316 (dry-run) |

### Data-Flow Trace (Level 4)

Not applicable -- this phase generates static configuration files, not dynamic data rendering.

### Behavioral Spot-Checks

| Behavior | Command | Result | Status |
|----------|---------|--------|--------|
| First-run creates SANDBOX.md | `rm -f ~/.claudebox/SANDBOX.md && nix run . -- --dry-run --yes; head -1 ~/.claudebox/SANDBOX.md` | `# Sandbox Environment` | PASS |
| First-run creates CLAUDE.md | `rm -f ~/.claudebox/CLAUDE.md && nix run . -- --dry-run --yes; cat ~/.claudebox/CLAUDE.md` | `@SANDBOX.md` | PASS |
| Idempotency (no duplicate import) | `nix run . -- --dry-run --yes; grep -c '@SANDBOX.md' ~/.claudebox/CLAUDE.md` | `1` | PASS |
| Prepend preserves user content | Write user content, run dry-run, check lines 1-2 | line 1: `@SANDBOX.md`, line 2: `# My custom stuff` | PASS |
| SANDBOX.md has 3 H2 sections | `grep -c '^## ' ~/.claudebox/SANDBOX.md` | `3` | PASS |

### Requirements Coverage

| Requirement | Source Plan | Description | Status | Evidence |
|-------------|------------|-------------|--------|----------|
| AWARE-01 | 03-01-PLAN | Default CLAUDE.md created in ~/.claudebox/ on first run if not present | SATISFIED | Lines 146-148: creates file with @SANDBOX.md if not present. Behavioral test confirmed. |
| AWARE-02 | 03-01-PLAN | Injected CLAUDE.md tells Claude about sandbox, comma/nix, and unavailable resources | SATISFIED | SANDBOX.md heredoc (lines 108-142) covers all three topics: bwrap sandbox identity, comma + nix shell installation, SSH/GPG/cloud restriction list. CLAUDE.md imports it via @SANDBOX.md. |

### Anti-Patterns Found

| File | Line | Pattern | Severity | Impact |
|------|------|---------|----------|--------|
| (none) | - | - | - | No TODOs, FIXMEs, placeholders, or stubs found |

### Human Verification Required

No human verification items identified. All behaviors verified programmatically via dry-run execution.

### Gaps Summary

No gaps found. All 4 must-have truths verified, all 3 artifacts confirmed, all 3 key links wired, both requirements (AWARE-01, AWARE-02) satisfied. Behavioral spot-checks all pass.

---

_Verified: 2026-04-09T21:30:00Z_
_Verifier: Claude (gsd-verifier)_