BF Regex Audit
Static ReDoS (Regular Expression Denial of Service) vulnerability scanner and regex quality auditor for codebases. Walks all source files to extract regex literals, detects catastrophic backtracking patterns (nested quantifiers, overlapping alternation, unbounded repetition on complex groups), severity-ranks each finding as CRITICAL/HIGH/MEDIUM, reports file and line number with the dangerous sub-pattern highlighted, identifies high-risk call sites (HTTP request handlers, form validators, URL parsers), and suggests safe rewrites using atomic groups or simplified alternatives. Also detects hardcoded locale assumptions (character classes assuming ASCII), overly permissive patterns, and regexes missing anchors. Supports JS/TS, Python, Go, Java, Ruby, PHP, Rust. Zero external API — pure static analysis. Triggers on "regex security", "ReDoS", "catastrophic backtracking", "regex audit", "slow regex", "regex vulnerability", "/regex-audit".
As a process F 32/100 · Will not run — References files that are not bundled: [^"\']{3,}, [^"\'\/\n]{3,}, [^"`]{3,}
How to improve
- Say in the description WHEN to use the skill ("use when…", example requests): that is the agent's main cue.
- The text references files that are not there: add them or drop the references.
- Your own cases (evals/evals.json, 4–6 real requests with expected answers): the full check would then run those instead of a model-drafted suite.
- A spec.yaml with trigger phrases and assertions — a behaviour contract for CI; `skilltest init` writes a template.
Guard findings · 0
✓ No critical or high findings
Files scanned: 2. Evidence is masked. Grey chips explain why severity was lowered.
Against the Agent Skills spec
- warning
name-formatname should be kebab-case (lowercase letters, digits, hyphens) - warning
description-no-whendescription does not say WHEN to use the skill (no "use when") - warning
missing-refreference to a missing file: [^"\']{3,} - warning
missing-refreference to a missing file: [^"\'\/\n]{3,} - warning
missing-refreference to a missing file: [^"`]{3,} - note
frontmatter-keyunknown frontmatter key "homepage"
Process rating: all ten parameters 32/100
- 0Tools and files. 3 referenced file(s) missing: [^"\']{3,}, [^"\'\/\n]{3,}, [^"`]{3,}
- 0Result and completion. Does not say what the result is
- 0Inputs and preconditions. Does not say what the process needs to start
- 0Failures and branches. Linear process with no failure handling
- 0Progress reporting. Says nothing while it works
- 30Running it twice. 1 mutating operations with no state check
- 40Consistency. Frontmatter name (Regex Audit) differs from the folder (phy-regex-audit)
- 70When it triggers. States when to use, but not when not to
- 70Execution cost. Instruction body is 4834 tokens
- 100Steps. 8 steps
Everything here is measured from the skill text rather than judged by a model, so the numbers are checkable. A parameter weighs more when it is a more common reason for the process to stall.
Quality signals
- +4Description does not say when NOT to use the skill (false activations)
- +3Description length 946: 120–800 characters recommended
- +3Output format is not stated: the model decides each time
- +2Single-language instructions
- +5Description quotes 6 example trigger phrases
- +4Structure: 11 headings
- +3Step-by-step instructions: 8 items
- +4Has examples (17 code blocks)
- +1License stated
Quality base 70; lint remarks subtract, signals add up to 100. Result: 57.