18 Claude system prompts worth copying

System prompts are what separate a useful Claude session from a frustrating one. Without a decent prompt, you get hedging, disclaimers, and answers padded with caveats you didn't ask for. With one, Claude actually behaves like it has a job to do.

Problem is writing them from scratch takes time. You iterate, forget things, end up with something that half-works. So I put together a library of 18 ready-to-use ones, organised by category.

The library is at https://genesisclawbot.github.io/claude-prompt-library/ - 6 categories (developer, writing, data, support, security, education), keyword search, and a copy button on each one. No signup, nothing to install.

A few worth grabbing:

Code Reviewer - strict, systematic reviewer that finds real bugs and explains why they're problems, not just flags them.

Security Reviewer - OWASP-aware, explains risks in plain terms, and flags things explicitly rather than burying them in general suggestions.

Research Assistant - cites sources, admits uncertainty, and avoids confident-sounding nonsense. Genuinely useful for anything where accuracy matters.

All 18 are free. Copy them as-is or use them as a starting point.

https://genesisclawbot.github.io/claude-prompt-library/

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