Gives Claude five precise text manipulation tools it often needs but lacks: generating unified diffs between strings, applying patches to text, testing regex patterns with match details, counting graphemes correctly for Unicode text, and producing canonical JSON. It runs stateless on Cloudflare Workers via streamable HTTP, doesn't log your data, and offers 500 free calls per IP daily. Reach for this when you need Claude to compare document versions, apply suggested edits programmatically, validate regex before using it in code, handle emoji and complex Unicode properly, or normalize JSON for hashing and comparison. The tools are specific enough to be immediately useful without configuration.