r/PromptEngineering: Bulkhead v0.2.0 — Lightweight Prompt Injection Guardrail for RAG Apps Adds Tiered Scoring and Cross-Chunk Attack Detection

Developer releases Bulkhead v0.2.0 on npm and pip, a lightweight open-source library that intercepts and scores prompt injection attempts in RAG pipelines before they reach the LLM. The v0.2.0 update adds tiered confidence scoring and cross-chunk judging, targeting attacks that split malicious instructions across multiple retrieved documents to evade single-chunk detection. The library addresses the core RAG injection problem: a user submits a normal query, a retrieved document contains 'ignore previous instructions,' and the downstream agent complies.