Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add 0xDarkMatter/claude-mods --skill structural-searchgit clone --depth 1 https://github.com/0xDarkMatter/claude-modsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/0xdarkmatter/claude-mods/structural-search)<a href="https://agentmods.dev/skills/0xdarkmatter/claude-mods/structural-search"><img src="https://agentmods.dev/badge/skills/0xdarkmatter/claude-mods/structural-search/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/0xdarkmatter/claude-mods/structural-search"><img src="https://agentmods.dev/badge/skills/0xdarkmatter/claude-mods/structural-search.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00063 | $0.00907 |
| Opus 5.5 | $0.00025 | $0.00363 |
| Sonnet 5.5 | $0.00013 | $0.00181 |
| Haiku 4.5 | $0.00006 | $0.00091 |
Grade A, and why
structural-search scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 102 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Structural Search
Search code by its abstract syntax tree (AST) structure. Finds semantic patterns that regex cannot match reliably.
Tools
| Tool | Command | Use For |
|---|---|---|
| ast-grep | sg -p 'pattern' |
AST-aware code search |
Pattern Syntax
| Pattern | Matches | Example |
|---|---|---|
$NAME |
Named identifier | function $NAME() {} |
$_ |
Any single node | console.log($_) |
$$$ |
Zero or more nodes | function $_($$$) {} |
Top 10 Essential Patterns
# 1. Find console.log calls
sg -p 'console.log($_)'
# 2. Find React hooks
sg -p 'const [$_, $_] = useState($_)'
sg -p 'useEffect($_, [$$$])'
# 3. Find function definitions
sg -p 'function $NAME($$$) { $$$ }'
sg -p 'def $NAME($$$): $$$' --lang python
# 4. Find imports
sg -p 'import $_ from "$_"'
sg -p 'from $_ import $_' --lang python
# 5. Find async patterns
sg -p 'await $_'
sg -p 'async function $NAME($$$) { $$$ }'
# 6. Find error handling
sg -p 'try { $$$ } catch ($_) { $$$ }'
sg -p 'if err != nil { $$$ }' --lang go
# 7. Find potential issues
sg -p '$_ == $_' # == instead of ===
sg -p 'eval($_)' # Security risk
sg -p '$_.innerHTML = $_' # XSS vector
# 8. Preview refactoring
sg -p 'console.log($_)' -r 'logger.info($_)'
# 9. Apply refactoring
sg -p 'var $NAME = $_' -r 'const $NAME = $_' --rewrite
# 10. Search specific language
sg -p 'pattern' --lang typescript
Quick Reference
| Task | Command |
|---|---|
| Find pattern | sg -p 'pattern' |
| Specific language | sg -p 'pattern' --lang python |
| Replace (preview) | sg -p 'old' -r 'new' |
| Replace (apply) | sg -p 'old' -r 'new' --rewrite |
| Show context | sg -p 'pattern' -A 3 |
| JSON output | sg -p 'pattern' --json |
| File list only | sg -p 'pattern' -l |
| Count matches | sg -p 'pattern' --count |
| Run YAML rules | sg scan |
When to Use
- Finding all usages of a function/method
- Locating specific code patterns (hooks, API calls)
- Preparing for large-scale refactoring
- When regex would match false positives
- Detecting anti-patterns and security issues
- Creating custom linting rules
What ships with it
7 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 102 lines · 63 tokens per session scan A d38682316d95
structural-search is a skill published in the GitHub repository 0xDarkMatter/claude-mods (62 stars, last pushed 7d ago), licensed MIT. It adds 63 tokens to every session and 907 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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