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 agentmods add skills/code-yeongyu/lazycodex/ast-grepnpx skills add code-yeongyu/lazycodex --skill ast-grepgit clone --depth 1 https://github.com/code-yeongyu/lazycodexWhat 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 | $0.00110 | $0.03303 |
| Opus 5 | $0.00055 | $0.01651 |
| Sonnet 5 | $0.00022 | $0.00661 |
| Haiku 4.5 | $0.00011 | $0.00330 |
Grade A, and why
ast-grep 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 2d 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 — 273 lines — stays where its author put it; the contents beside it link to each section on GitHub.
ast-grep
sg (also installed as ast-grep) is an AST-aware search and rewrite tool across 25 languages. It treats your pattern as code, parses it the same way it parses your project, and matches structurally. It is the right tool whenever your question depends on code shape rather than text bytes.
This skill ships a Python wrapper at scripts/ast_grep_helper.py and platform install scripts at install.sh (POSIX) and install.ps1 (Windows). The helper adds offline pattern validation, the two-pass write trick, and binary auto-resolution. Use it as your default entry point.
When to use this skill
Use it whenever the user's question is about code structure, not bytes:
- "Find every function that takes a
Requestparameter." - "Rewrite every
console.log(x)tologger.info(x)." - "Strip every
as anycast." - "Replace
require(...)withimportacross the repo." - "Find empty catch blocks."
- "Migrate
Optional[X]toX | None." - "Apply this codemod across these 200 files."
- "Run our YAML lint rules and surface violations."
Switch to plain grep / rg when the question is text-shaped (string literal contents, comments, license headers, file names, cross-language regex). When in doubt, ask: "does the answer depend on the language's syntax tree, or just on the file's bytes?" If the former, ast-grep. If the latter, grep.
Three things the agent must internalize
1. ast-grep is NOT regex
The wildcards are $VAR (one AST node) and $$$ (zero or more nodes). Regex syntax fails silently:
| You wrote | What ast-grep saw | What you wanted |
|---|---|---|
foo|bar |
bitwise-or of foo and bar |
run two separate searches |
.*foo |
not parseable | $$$ foo (if $$$ is a list of nodes) or use rg |
\w+ |
not parseable | $VAR to capture any identifier |
[a-z] |
character class, not parseable | switch to rg |
The full anti-pattern table is in references/pitfalls.md §1. The helper's validate subcommand catches these mechanically — call it before debugging "no matches" by hand.
What ships with it
16 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.
- agents/openai.yaml 43 B
- install.ps1 7.0 KB runs code
- install.sh 7.4 KB runs code
- LICENSE 1.0 KB
- README.md 7.5 KB
- references/cli.md 7.1 KB
- references/install.md 5.5 KB
- references/patterns.md 5.4 KB
- references/pitfalls.md 8.7 KB
- references/recipes.md 7.7 KB
- references/sgconfig.md 6.3 KB
- references/yaml-rules.md 11 KB
- scripts/ast_grep_helper.py 26 KB runs code
- SOURCE 125 B
- tests/smoke.ps1 5.6 KB runs code
- tests/smoke.sh 7.6 KB runs code
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.
- 2d ago First seen · 273 lines · 110 tokens per session scan A c5512fb49494
ast-grep is a skill published in the GitHub repository code-yeongyu/lazycodex (3,363 stars, last pushed 23d ago), licensed MIT. It adds 110 tokens to every session and 3,303 once invoked, about $0.0006 per session on Opus 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 2026-08-30.
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