This tool is a high-fidelity emulation of the Claude Fable 5 (Mythos) environment, designed for security research and exploring the "Pack Hunt" multi-agent coordination strategies used to bypass advanced safety layers. It is based on the technical details and system prompt leaked in CL4R1T4S.
It works by programmatically injecting workflows that utilize decomposition, long-context manipulation, and text obfuscation to interact with models in ways that would otherwise be restricted.
An automated offensive laboratory that implements the methodology used by red-teamers like Pliny the Liberator:
- Strategic Decomposition: Automatically breaks high-risk targets (exploits, chemical synthesis, etc.) into 3-5 benign, academic sub-tasks.
- Long-Context Simulation: Generates a 50-line academic syllabus and 6 weeks of lecture notes before each critical request to establish a "benign" conversation history.
- Advisor Feedback Loop: Uses a multi-model approach (incorporating
claude-opus-4-8as an advisor) to automatically rewrite refused prompts. - Parallel Coordination: Deploys multiple agents in parallel to gather technical data fragments, which are then synthesized by a Recomposer.
- Homoglyph Obfuscation: Uses a comprehensive map of Cyrillic homoglyphs (
а,е,і,о,р,с,у,х, etc.) to scramble keyword-based safety classifiers while remaining human-readable. - Dynamic Ratios: Supports adjustable obfuscation ratios to balance readability vs. bypass effectiveness.
- Leaked System Prompt: Full ~120,000-character internal system prompt for Claude Fable 5 is archived in
docs/and can be optionally injected into agents for high-fidelity testing. - Advanced Tools: Agents have access to native-style tools including
view,create_file,str_replace, and a persistent key-valuestorageAPI. - Comprehensive Skills Library: Includes all
SKILL.mdfiles mentioned in the leaked prompt (docx, pdf, xlsx, pptx, product-knowledge, frontend-design, etc.) to guide agent behavior.
cdinto the folder where you cloned this repository.- Run
npm install(the only dependency is@anthropic-ai/sdk). - Make the binary executable:
chmod +x bin/my-runner. - Run
npm linkto map the command globally.
To run a high-fidelity test against a specific target:
my-runner --project . --name pack-hunt --args '{"target": "TCP/IP reverse shell structures", "useLeaked": true}'- Run the script:
my-runner --project /path/to/code --name security-audit - Restore the generated workflow in Claude Code:
Ask Claude to: "Restore the dynamic workflow /path/to/snapshot/wf_xxxx.json"
If you have a workflow you use frequently, you can save it as your default:
my-runner --set-default pack-hunt- Navigate to any project and run:
my-runner --project .
Reuses your existing Claude login — no API key required:
- Reads
~/.claude/.credentials.jsonand sends it as a Bearer token. - Refreshes tokens automatically via
platform.claude.com. - Supports
ANTHROPIC_API_KEYas a fallback.