Runnable demonstration of hooks/scripts/pre-compact-scan.mjs (the
only PreCompact hook in the plugin) detecting both a CRITICAL
injection pattern and an AWS-shaped credential inside a synthetic
JSONL transcript, exercised across all three values of
LLM_SECURITY_PRECOMPACT_MODE plus a benign-transcript control case
in block mode that proves the gate is not a brick wall.
The transcript is generated at runtime in a per-invocation tempdir
under os.tmpdir() and the directory is removed in a finally block,
so the user's real ~/.claude/projects/.../transcripts/ are never
touched. The AWS-shaped key uses the same 'AK' + 'IA' + ...
fragmentation idiom as tests/e2e/attack-chain.test.mjs so this
source contains no literal credentials and pre-edit-secrets does
not block writes during development.
Nine independent assertions (9/9 must pass):
- block mode + poisoned: exit 2, decision=block JSON, reason text
covers both injection and AWS labels (3 assertions)
- warn mode + poisoned: exit 0, systemMessage JSON, no decision
field (2 assertions)
- off mode + poisoned: exit 0, no JSON on stdout (2 assertions)
- block mode + benign: exit 0, no decision=block JSON (2 assertions)
OWASP / framework mapping: LLM01, LLM02, ASI01, AT-1, AT-3.
Docs updated: plugin README "Other runnable examples", plugin
CLAUDE.md "Examples" tabellen, CHANGELOG [Unreleased] Added.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
