{"slug":"ast-grep","title":"ast-grep","summary":"Use ast-grep (sg) for AST-aware code search and rewrite across 25 languages. Trigger for structural code matching or deterministic codemods: find every function/call/class/import shaped like X, rewrite console.log to logger.info, strip `as any`, migrate require() to import, find ","platform":"Claude","tags":[],"authorName":"LLM Mart","authorSlug":"llm-mart","score":0,"source":"github","price":null,"verified":false,"createdAt":"2026-08-23T08:58:16.221168Z","repo":{"url":"https://github.com/code-yeongyu/oh-my-openagent","stars":69391,"forks":5715,"license":null,"updatedAt":"2026-09-24T23:30:44Z"},"bodyHtml":"

ast-grep-skill

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LLM-neutral skill for AST-aware search and rewrite across 25 languages. Wraps the ast-grep (sg) CLI with offline pattern validation, the two-pass write trick, binary auto-resolution, and a per-OS installer.

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Same shape as web-fetch and web-search, packaged as a standalone skill that any Bash-capable agent (Claude Code, OpenCode, pi, hermes, openclaw) can load.

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Install

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git clone https://github.com/code-yeongyu/ast-grep-skill ~/.agents/skills/ast-grep\nbash ~/.agents/skills/ast-grep/install.sh        # installs the ast-grep binary\n
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That is it. The wrapper script is single-file Python 3 stdlib; no pip install needed. The installer tries brew → npm → cargo → pip → nix → mise → GitHub release in priority order, picks the first that works, and falls back to a cached binary at <skill>/bin/sg.

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Symlink for active development

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ln -s /path/to/your/clone ~/.agents/skills/ast-grep\n
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Other agents

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Usage

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# Search by AST pattern (the helper validates patterns offline first)\npython3 scripts/ast_grep_helper.py search 'console.log($MSG)' --lang ts src/\n\n# Rewrite (dry-run preview by default)\npython3 scripts/ast_grep_helper.py replace 'console.log($MSG)' 'logger.info($MSG)' --lang ts src/\n\n# Apply the rewrite (two-pass: preview JSON + then --update-all)\npython3 scripts/ast_grep_helper.py replace 'console.log($MSG)' 'logger.info($MSG)' --lang ts src/ --apply\n\n# Run YAML lint rules from sgconfig.yml\npython3 scripts/ast_grep_helper.py scan src/\n\n# Validate a pattern OFFLINE (no sg call, no filesystem)\npython3 scripts/ast_grep_helper.py validate '\\w+' --lang ts\n# → exit 2: regex \\w not supported. Use $VAR for identifiers.\n\n# Doctor: check ast-grep binary availability\npython3 scripts/ast_grep_helper.py doctor\n\n# List 25 supported languages\npython3 scripts/ast_grep_helper.py langs\n\n# Install / re-install the ast-grep binary\npython3 scripts/ast_grep_helper.py install\n
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See SKILL.md for full agent-facing usage and the references/ directory for deep dives.

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Project layout

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ast-grep-skill/\n├── SKILL.md                       agent-facing skill (loaded by Claude Code, OpenCode, pi, etc.)\n├── README.md                      this file\n├── LICENSE                        MIT\n├── install.sh                     POSIX installer (macOS / Linux / WSL / Git Bash)\n├── install.ps1                    Windows PowerShell installer\n├── scripts/\n│   └── ast_grep_helper.py         single-file Python 3 stdlib wrapper\n├── references/\n│   ├── install.md                 per-OS install methods + manual fallback\n│   ├── patterns.md                meta-variables ($VAR, $$$) and pattern syntax\n│   ├── pitfalls.md                regex anti-patterns + language-specific traps\n│   ├── recipes.md                 copy-paste patterns by language (TS/JS/Py/Go/Rust/...)\n│   ├── cli.md                     sg run / scan / test / new / lsp reference\n│   ├── yaml-rules.md              YAML rule schema (atomic / relational / composite / transform / fix)\n│   └── sgconfig.md                project configuration (ruleDirs, testConfigs, utilDirs)\n├── tests/\n│   ├── smoke.sh                   POSIX self-test\n│   └── smoke.ps1                  PowerShell self-test (Windows CI)\n└── .github/workflows/ci.yml       matrix CI: macos / ubuntu / windows × py 3.9-3.13\n
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What it does

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  1. Wraps sg with a single Python 3 stdlib script that works the same on macOS, Linux, Windows, WSL, Git Bash.
    2. \n
  2. Validates patterns offline before calling sg — catches the regex-misuse class of mistakes (\\w, .*, |, [a-z]) plus language-specific traps (Python trailing colons, JS/Go/Rust missing function bodies).
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  3. Resolves the binary through 6 candidate paths: cached → PATH (with Linux setgroups collision detection) → Homebrew. Falls through to a clear install hint with copy-paste commands.
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  4. Runs the two-pass write trick when applying rewrites — sg run silently ignores --update-all when --json is set, so replace --apply runs two invocations: pass 1 collects JSON matches, pass 2 mutates files.
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  5. Ships per-OS installers that try every reasonable package manager and fall back to a GitHub release tarball.
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  6. Documents the failure modes the model will hit (regex misuse, incomplete patterns, --update-all + --json trap, scope/type questions ast-grep can't answer) in references/pitfalls.md.
    7. \n
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What it does NOT do

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Limits

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Requirements

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For older systems and Windows-specific setup, see references/install.md.

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Testing

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bash tests/smoke.sh        # POSIX (macOS / Linux / WSL / Git Bash)\npwsh tests/smoke.ps1       # Windows (PowerShell 5.1+ or 7+)\n
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CI runs the matrix on every push: {macos-latest, ubuntu-latest, ubuntu-22.04, windows-latest} × {Python 3.9, 3.10, 3.11, 3.12, 3.13} plus a syntax-floor check on Python 3.9 and 3.10.

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License

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MIT.

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Acknowledgments

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