regex
Test, match, matchAll, replace
How to use it
regex is exposed by the Calc MCP MCP server. Add the server to your MCP client (Claude Desktop, Cursor, Windsurf and others), and the regex tool becomes available to the model automatically. See the full listing for setup details and every tool this server provides.
Install Calc MCP
claude mcp add -s user calc-mcp -- npx -y @coo-quack/calc-mcp@2.1.0Other tools in Calc MCP (20)
Number base conversion (2–36)
Encode / decode
Unicode code point, block, category
HEX ↔ RGB ↔ HSL (alpha channel supported)
8 categories, 146 unit names: length, weight, temperature, area (tsubo, tatami), volume, speed, data, time
Characters (grapheme-aware), words, lines, bytes
Human-readable cron + next runs (weekday/month names supported)
Diff, add/subtract, weekday, wareki
Current time, timezone conversion, UNIX timestamps
Line diff, Levenshtein distance
URL, HTML entity, Unicode escape
Validate JSON, CSV, XML, YAML
MD5, SHA-1, SHA-256, SHA-512, CRC32, HMAC
IPv4/IPv6 info, CIDR contains check, range calculation
Decode header + payload (no verification)
Validate / generate check digits
Evaluate expressions, statistics
UUID v4/v7, ULID, passwords (readable, custom charset), random number, shuffle
Compare, validate, parse, range satisfaction
Protocol, host, path, params, hash