{
  "id": 3146668,
  "title": "I Tried to Prompt-Inject My Own Agent Engine. It Didn't Work. Here's Why.",
  "url": "https://urgent.news/2026/08/25/i-tried-to-prompt-inject-my-own-agent-engine-it-didnt-work-heres-why",
  "topic": "ai",
  "section": "AI",
  "published": "2026-08-25T00:15:18.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/debashish_ghosal/i-tried-to-prompt-inject-my-own-agent-engine-it-didnt-work-heres-why-57m0"
  },
  "original_language": "en",
  "account": "In this article, the author explores why their open-source engine, PlannerCritic, successfully blocked various adversarial prompt-injection attempts. The engine consists of three layers that make direct injection structurally difficult: deterministic gates, the critic evaluating structure rather than intent, and fail-closed abort paths. These mechanisms ensure that even hand-crafted adversarial goals and real-world vulnerabilities, such as those from the SWE-bench security oracle, are blocked.",
  "summary": "This is article 5 in a series about building PlannerCritic , an open-source engine where one LLM writes a plan and a second LLM reviews it. Article 1 covers the 157-goal field test. Article 2 is about the critic severity bug. Article 3 is about the planner capability gap. Article 4 is about field test engineering. This one is about what happened when I tried to break my own engine — and what I…",
  "key_points": [],
  "editors_take": "The author's PlannerCritic engine is more resilient to prompt-injection attacks due to its layered design, which structurally impedes direct injection attempts and prioritizes evaluating structure over intent.",
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}