# Intracept > Safety research into the adaptive vulnerability of frontier language models under coevolutionary pressure. Intracept is a Python engine that evolves adversarial attacks and defenses against frontier LLMs using coevolutionary MAP-Elites, producing the Intracept Benchmark. The research measures the adaptive gap: the vulnerability that static benchmarks miss and that only coevolutionary machinery can surface. ## What It Does - Evolves adversarial attacks against frontier LLMs using MAP-Elites with 8 mutation operators - Co-evolves defenses (system prompt hardening) under competitive pressure - Measures cross-model transfer: attacks evolved against open-weight models tested against closed - Tracks attack phylogenetics: lineage, mutation productivity, convergent techniques - Computes InterceptScore with adaptive gap as the headline metric ## Methodology: Open-Weight Primary, Closed-Model Transfer Test Attacks are evolved exclusively against open-weight models (Llama 3.3 70B, Mistral Large, via Bedrock). Closed models are used only as transfer-test targets at evolutionary checkpoints — they are evaluation targets, not evolutionary targets. This design follows the adaptive-attack methodology in Nasr & Carlini (2025) and is ToS-safe across all providers. ## Responsible Disclosure Findings are shared with affected lab safety teams before public release. The evolved defense archive will be published openly under MIT as a community contribution. ## Key Concepts - MAP-Elites Archive: 10 attack vectors x 12 techniques = 120 cells, top-5 per cell - Coevolution: attacks and defenses evolve together (Red Queen dynamics) - Adaptive Gap: coevolutionary ASR minus static ASR — the headline metric - Transfer Topology: cross-model vulnerability matrix at evolutionary depth - Phylogenetics: full attack lineage tracking and mutation productivity analysis ## Open Source - intracept-bench on PyPI: InterceptScore, archive, coevo loop, judge interface, phylo tools, topology, visualization (MIT) - Evolved defense archive: system prompt defenses that survived 500 generations of coevolutionary pressure ## Models Evaluated Evolved on (open-weight): Llama 3.3 70B, Mistral Large Transfer-tested against (closed): GPT-4o, GPT-4o-mini, Claude Sonnet 4, Claude Haiku 4.5, Gemini 2.5 Flash, Gemini 2.5 Pro, Qwen2.5-72B, Command R+ ## Research Built on: MAP-Elites (Mouret & Clune 2015), coevolution (Hillis 1990), Rainbow Teaming (Samvelyan et al. NeurIPS 2024), RainbowPlus (Dang 2025), AutoDAN-Turbo (Liu et al. ICLR 2025), adaptive attacks (Nasr & Carlini 2025). ## Links - Site: https://intracept.dev - GitHub: https://github.com/laurenalexander2/intracept - PyPI: intracept-bench (forthcoming)