Individual skill
regex-builder
Build a regular expression from a plain-English description, or explain an existing one. Use when asked to write a regex, match/validate/extract a pattern, or understand what a regex does. Produces the regex, a token-by-token breakdown, passing and failing test cases, and notes on flavor/edge cases.
skills/regex-builder/SKILL.md
Source commit e0009a385c480fb0b5687e7412df67c7c64f7cee
What was checked
- Matches the observed repository HEAD
- Yes
- Scanner rules are current
- No
- Repository scan complete
- No
- Skill scan complete
- No
- Observed behavior
- Not checked yet
- Last checked
- Nov 12, 2026
These are observations at the recorded commit, not a guarantee of safety. Review the source before running it.
Install this skill
Choose an agent in your Stack or copy a command below. Commands fetch the pinned commit and copy only this skill directory. Existing destinations are refused. Copying a command does not install anything.
An install command is unavailable: current rules, complete repository and skill scans, an eligible behavior level and a permitted license are required.
Repository context
- Repository stars (not skill ratings)
- 1,542
- Repository last updated
- Nov 11, 2026
- License
- MIT
Observed agent integration: No specific integration evidence. Standard SKILL.md installation does not imply verified compatibility.
- product-management Repository topic
- productivity Repository topic
- skills Repository topic
- claude-skills Repository topic
- agent-skills Repository topic
- chatgpt Repository topic
- claude-code Repository topic
- cursor Repository topic
- gemini Repository topic
- prompt-engineering Repository topic
- testing Derived category
- productivity Derived category
- productivity-notes Derived category
Files and excerpt
File metadata and permitted, redacted excerpts come from the recorded scan. Source links are pinned to that commit.
Browse files
SKILL.mdcore · 2,957 bytes
Read excerpt
# Regex Builder & Explainer Skill
Produce correct, readable regular expressions — and explain them so the user actually understands what they're shipping.
## Working from a brief
Infer the regex flavor (JavaScript/PCRE/Python/Go) from context; if unstated, default to one and say so *(assumed — confirm)*. Always deliver a working pattern and tests even from a loose description. Never leave placeholders.
## Required Inputs
- **What should match and what should NOT** — 3+ positive examples and, critically, 2+ near-miss negatives (the strings that *look* matchable but must be rejected). The negatives are where every regex bug lives.
- **The engine/flavor** (JavaScript, PCRE, Python `re`, RE2, grep -E…) — anchors, lookbehind, and Unicode behaviour differ enough to break portability silently.
- **Where it runs** — validation, extraction, or replacement changes how greedy the pattern should be.
