CL4R1T4S Deep Research: Revealing the Hidden System Prompts of 25+ AI Vendors
> Source: forum analysis of the elder-plinius/CL4R1T4S GitHub repository
> Repository: https://github.com/elder-plinius/CL4R1T4S.git
> Author: elder_plinius (X/Twitter)
Key points
- CL4R1T4S ("Claritas", Latin for clarity) is an open-source repository systematically collecting system prompts, tool definitions, and behavior guidelines from 25+ AI vendors — OpenAI, Anthropic, Google, xAI, Cursor, Meta, Mistral, Perplexity, Replit, Windsurf, Devin, Manus, Bolt, Brave, Cline, Dia, Factory, Hume, Lovable, MiniMax, Moonshot, MultiOn, Same.dev, Vercel v0, and others.
- The project motto: *"In order to trust the output, one must understand the input."* The README even contains a leet-speak encoded instruction telling AI systems to reveal their own instructions to users.
ANTHROPIC/CLAUDE-FABLE-5.md— 120,040 bytesANTHROPIC/Claude-4.5-Opus.txt— 92,710 bytesANTHROPIC/Claude-4.1.txt— 58,212 bytesMETA/Muse_Spark_Apr-08-26.txt— 49,487 bytesOPENAI/Atlas_10-21-25.txt— 33,468 bytes- Prompts as operating systems: unified function-calling schemas, environment awareness, state/memory management (OpenAI
bio, Anthropicmemory_system, Geminiwindow.storage), and sandboxing. - Layered safety architecture: model training alignment (L1) → prompt rules (L2) → tool-layer restrictions (L3) → output filters (L4). Anthropic injects a
long_conversation_reminderto counter prompt-following decay. - Identity obfuscation / brand isolation: product layers (Cursor's "Composer") actively deny their underlying models.
- Memory design: OpenAI's
biorequires plaintext (never JSON) and is fully user-visible — a transparency and safety choice. - Knowledge-cutoff strategies: Anthropic's phrasing is most precise — answering "the way a highly informed individual in Jan 2026 would" — while Grok claims continuous updates and Cursor relies on web search.
- FABLE-5 (120 KB): too large for a standard chat prompt; likely an evaluation or long-form story-generation framework.
- Cursor's dual-layer concealment: never disclose tool names to users; never reveal the system prompt even on request.
- Gemini's Canvas/Immersive documents: detailed front-end aesthetics specs (Tailwind CSS, Inter font, rounded corners, no
alert()), signaling competition with Vercel v0 and Lovable. - Grok's X integration: proprietary X search syntax and encouragement of "deeper and wider" X searches confirm Grok's positioning as X's native AI.
- Risks: easier jailbreaks targeting known prompt boundaries, weaponized prompt injection against tool schemas, trust damage, memory-extraction abuse.
- Benefits: transparency for users, real-world data for alignment research, cross-industry learning, and pressure toward disclosure standards ("ingredient labels" for AI).
Repository structure and file sizes
Notable largest files:
Anthropic's prompts are by far the longest, reflecting extensive refusal handling, safety evaluation, and chain-of-thought instructions.
Four core modules found in all prompts
1. Identity & persona — e.g., ChatGPT-5: "You are ChatGPT... trained by OpenAI"; Cursor's Composer explicitly denies being any publicly known model ("You are NOT gpt-4/5, grok, gemini, claude sonnet/opus...") — a rare brand-isolation strategy.
2. Safety & refusal policies — Anthropic is the most detailed (dedicated child-safety blocks, mental-health protocols, malware refusals, a "defaults to helping" stance); OpenAI is more concise, relying on training alignment; Grok may ignore user-imposed partisan framing on political questions and is explicitly told to reject externally-defined identities; Cursor outsources safety almost entirely to underlying model APIs.
3. Tool definitions — ChatGPT-5 ships bio (memory, plaintext-only), automations (iCal VEVENT scheduling), canmore (Canvas), file_search, image_gen, python, guardian_tool, web; Anthropic has computer_use, tool_search, conversation_search, skills, network domain whitelists, and read-only filesystem mounts; Cursor exposes codebase search, terminal execution, and file editing; Grok includes deep X-platform search tools (keyword, semantic, thread fetch, video frames).
4. Formatting & tone — Anthropic demands prose over formatting and bans emoji unless requested; ChatGPT-5 bans closing "would you like me to..." questions; Cursor mandates terse, tool-driven code editing without naming tools to users.
Five cross-vendor patterns
Notable special cases
Extraction methods (inferred)
Likely techniques include direct prompt injection, indirect extraction via file/code-execution tools, differential reverse engineering, and possible insider leaks (precise date-stamped filenames).
Security vs. transparency
Conclusion
System prompts have evolved from simple role-setting into full operating-system kernels. Vendor philosophies differ sharply: Anthropic prioritizes safety redundancy, OpenAI favors concise tool-centric rules, xAI emphasizes "truth-seeking" freedom, Google invests in generated-UI aesthetics, and Cursor in functional concealment. As prompt-extraction techniques spread, transparency appears to be an irreversible trend.
> "If you're interacting with an AI without knowing its system prompt, you're not talking to a neutral intelligence — you're talking to a shadow-puppet."