Agent skill

Jscodeshift

jscodeshift codemod development best practices from Facebook/Meta.

MITAuto-check passedDevelopment

Install Jscodeshift

skills CLI

$ npx skills add pproenca/dot-skills --skill jscodeshift -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install pproenca/dot-skills jscodeshift --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/.experimental/jscodeshift .claude/skills/jscodeshift && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "jscodeshift" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.experimental/jscodeshift into .claude/skills/jscodeshift/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jscodeshift", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/pproenca/dot-skills/tree/master/skills/.experimental/jscodeshift

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add pproenca/dot-skills --skill jscodeshift -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install pproenca/dot-skills jscodeshift --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/.experimental/jscodeshift .agents/skills/jscodeshift && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "jscodeshift" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.experimental/jscodeshift into .agents/skills/jscodeshift/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jscodeshift", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add pproenca/dot-skills --skill jscodeshift -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install pproenca/dot-skills jscodeshift --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/.experimental/jscodeshift .cursor/skills/jscodeshift && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "jscodeshift" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.experimental/jscodeshift into .cursor/skills/jscodeshift/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jscodeshift", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/pproenca/dot-skills.git --path skills/.experimental/jscodeshift

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add pproenca/dot-skills --skill jscodeshift -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install pproenca/dot-skills jscodeshift --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/.experimental/jscodeshift .gemini/skills/jscodeshift && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "jscodeshift" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.experimental/jscodeshift into .gemini/skills/jscodeshift/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jscodeshift", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install pproenca/dot-skills jscodeshift

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add pproenca/dot-skills --skill jscodeshift -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/.experimental/jscodeshift .github/skills/jscodeshift && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "jscodeshift" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.experimental/jscodeshift into .github/skills/jscodeshift/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jscodeshift", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add pproenca/dot-skills --skill jscodeshift -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install pproenca/dot-skills jscodeshift --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/pproenca/dot-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/.experimental/jscodeshift .opencode/skills/jscodeshift && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "jscodeshift" agent skill from https://github.com/pproenca/dot-skills/tree/master/skills/.experimental/jscodeshift into .opencode/skills/jscodeshift/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "jscodeshift", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: jscodeshift
GitHub stars: 214
Token cost: ~1.8k tokens
SKILL.md length: 513 words
Files: 46 (incl. references, assets)
Skills in repo: 182
Repo updated: Aug 15, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

jscodeshift codemod development best practices from Facebook/Meta.

Works in 8 steps: Parser Configuration (CRITICAL) → AST Traversal Patterns (CRITICAL) → Node Filtering (HIGH) → …
Tasks involving AST transformation
SKILL.md covers When to Apply, Rule Categories by Priority, Quick Reference and How to Use, plus 2 more sections
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

Jscodeshift is an agent skill from pproenca/dot-skills. jscodeshift codemod development best practices from Facebook/Meta. This skill should be used when writing, reviewing, or debugging jscodeshift codemods. Triggers on tasks involving AST transformation, code migration, automated refactoring, or codemod development.

Its SKILL.md is about 1.8k tokens, which your agent loads only when the skill is triggered. The skill folder holds 48 other files, including reference files and assets (for example `AGENTS.md`, `README.md` and `assets/templates/_template.md`).

It sits in Development, covering Code migrations. It works with TypeScript. The repository describes itself as: A collection of AI agent skills following the Agent Skills open format. The licence is MIT.

When your agent uses it

Tasks involving AST transformation
Automated refactoring
Codemod development

Example prompts

“/jscodeshift”

Workflow steps

8 steps, taken from the step headings in SKILL.md.

Parser Configuration (CRITICAL)
AST Traversal Patterns (CRITICAL)
Node Filtering (HIGH)
AST Transformation (HIGH)
Code Generation (MEDIUM)
Testing Strategies (MEDIUM)
Runner Optimization (LOW-MEDIUM)
Advanced Patterns (LOW)

What it can do on your machine

Read from SKILL.md and the folder at commit cf93c57. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Jscodeshift loads about 1.8k tokens when it runs, and up to ~20k if it reads all its reference files. Until then it costs about 69 tokens; SKILL.md has 513 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~69
When it runs · the whole SKILL.md, loaded when a task matches: ~1.8k
With references · SKILL.md plus every file in references/, read only if the agent opens them: ~20k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from pproenca/dot-skills at commit cf93c57, republished under its MIT licence (© pproenca). 513 words, ~1,782 tokens.

Download SKILL.mdSave it as .claude/skills/jscodeshift/SKILL.md (or your agent's skills folder). This skill also uses 45 other files; get the full folder from GitHub.

name: jscodeshift
description: jscodeshift codemod development best practices from Facebook/Meta. This skill should be used when writing, reviewing, or debugging jscodeshift codemods. Triggers on tasks involving AST transformation, code migration, automated refactoring, or codemod development.

Facebook/Meta jscodeshift Best Practices

Comprehensive best practices guide for jscodeshift codemod development, designed for AI agents and LLMs. Contains 40 rules across 8 categories, prioritized by impact from critical (parser configuration, AST traversal) to incremental (advanced patterns). Each rule includes detailed explanations, real-world examples, and specific impact metrics.

When to Apply

Reference these guidelines when:

Writing new jscodeshift codemods for code migrations
Debugging transform failures or unexpected behavior
Optimizing codemod performance on large codebases
Reviewing codemod code for correctness
Testing codemods for edge cases and regressions

Rule Categories by Priority

Priority	Category	Impact	Prefix
1	Parser Configuration	CRITICAL	`parser-`
2	AST Traversal Patterns	CRITICAL	`traverse-`
3	Node Filtering	HIGH	`filter-`
4	AST Transformation	HIGH	`transform-`
5	Code Generation	MEDIUM	`codegen-`
6	Testing Strategies	MEDIUM	`test-`
7	Runner Optimization	LOW-MEDIUM	`runner-`
8	Advanced Patterns	LOW	`advanced-`

Quick Reference

1. Parser Configuration (CRITICAL)

parser-typescript-config - Use correct parser for TypeScript files
parser-flow-annotation - Use Flow parser for Flow-typed code
parser-babel5-compat - Avoid default babel5compat for modern syntax
parser-export-declaration - Export parser from transform module
parser-astexplorer-match - Match AST Explorer parser to jscodeshift parser

2. AST Traversal Patterns (CRITICAL)

traverse-find-specific-type - Use specific node types in find() calls
traverse-two-pass-pattern - Use two-pass pattern for complex transforms
traverse-early-return - Return early when no transformation needed
traverse-find-filter-pattern - Use find() with filter object over filter() chain
traverse-closest-scope - Use closestScope() for scope-aware transforms
traverse-avoid-repeated-find - Avoid repeated find() calls for same node type

3. Node Filtering (HIGH)

filter-path-parent-check - Check parent path before transformation
filter-import-binding - Track import bindings for accurate usage detection
filter-nullish-checks - Add nullish checks before property access
filter-jsx-context - Distinguish JSX context from regular JavaScript
filter-computed-properties - Handle computed property keys in filters

4. AST Transformation (HIGH)

transform-builder-api - Use builder API for creating AST nodes
transform-replacewith-callback - Use replaceWith callback for context-aware transforms
transform-insert-import - Insert imports at correct position
transform-preserve-comments - Preserve comments when replacing nodes
transform-renameto - Use renameTo for variable renaming
transform-remove-unused-imports - Remove unused imports after transformation

Show full SKILL.md (204 more words)Show less

5. Code Generation (MEDIUM)

codegen-tosource-options - Configure toSource() for consistent formatting
codegen-preserve-style - Preserve original code style with recast
codegen-template-literals - Use template literals for complex node creation
codegen-print-width - Set appropriate print width for long lines

6. Testing Strategies (MEDIUM)

test-inline-snapshots - Use defineInlineTest for input/output verification
test-negative-cases - Write negative test cases first
test-dry-run-exploration - Use dry run mode for codebase exploration
test-fixture-files - Use fixture files for complex test cases
test-parse-errors - Test for parse error handling

7. Runner Optimization (LOW-MEDIUM)

runner-parallel-workers - Configure worker count for optimal parallelization
runner-ignore-patterns - Use ignore patterns to skip non-source files
runner-extensions-filter - Filter files by extension
runner-batch-processing - Process large codebases in batches
runner-verbose-output - Use verbose output for debugging transforms

8. Advanced Patterns (LOW)

advanced-compose-transforms - Compose multiple transforms into pipelines
advanced-scope-analysis - Use scope analysis for safe variable transforms
advanced-multi-file-state - Share state across files with options
advanced-custom-collections - Create custom collection methods

How to Use

Read individual reference files for detailed explanations and code examples:

Section definitions - Category structure and impact levels
Rule template - Template for adding new rules

Full Compiled Document

For a single comprehensive document containing all rules, see AGENTS.md.

Reference Files

File	Description
AGENTS.md	Complete compiled guide with all rules
references/_sections.md	Category definitions and ordering
assets/templates/_template.md	Template for new rules
metadata.json	Version and reference information

Files

SKILL.md and 45 other files (references, assets) in skills/.experimental/jscodeshift of pproenca/dot-skills.

SKILL.md
AGENTS.md
README.md
assets/templates/_template.md
metadata.json
references/_sections.md
references/advanced-compose-transforms.md
references/advanced-custom-collections.md
references/advanced-multi-file-state.md
references/advanced-scope-analysis.md
references/codegen-preserve-style.md
references/codegen-print-width.md
references/codegen-template-literals.md
references/codegen-tosource-options.md
references/filter-computed-properties.md
references/filter-import-binding.md
references/filter-jsx-context.md
references/filter-nullish-checks.md
… and 28 more

Open the folder on GitHubat commit cf93c57

Compare with similar skills

Jscodeshift next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Jscodeshift compared with similar skills
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jscpd Code Migration Trackerkucherenko/jscpd	6.3k	—	~5k	Automated safety check: Pass	MIT	yesterday
ast-grep Codemod Referencewarp-drive-data/warp-drive	3.2k	—	~2.6k	Automated safety check: Pass	MIT	yesterday
Codemodpmndrs/glyph	392	—	~1.2k	Automated safety check: Pass	MIT	today
Code Migrationanthropics/code-migration-kit-with-claude-code	742	—	~983	Automated safety check: Pass	Custom licence	3 mo ago

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Questions about Jscodeshift

What does Jscodeshift do?

jscodeshift codemod development best practices from Facebook/Meta. Jscodeshift is an agent skill from pproenca/dot-skills. jscodeshift codemod development best practices from Facebook/Meta.

When should I use Jscodeshift?

Jscodeshift fits situations like: tasks involving AST transformation; automated refactoring; codemod development.

How do I install Jscodeshift in Claude Code?

Run `npx skills add pproenca/dot-skills --skill jscodeshift -a claude-code`. Or copy the skill folder (skills/.experimental/jscodeshift in pproenca/dot-skills) into .claude/skills/jscodeshift in your project. Claude Code loads it when a task matches its description.

How do I install Jscodeshift in Codex?

Run `npx skills add pproenca/dot-skills --skill jscodeshift -a codex`. Or copy the skill folder (skills/.experimental/jscodeshift in pproenca/dot-skills) into .agents/skills/jscodeshift in your project. Codex loads it when a task matches its description.

Can I use Jscodeshift in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add pproenca/dot-skills --skill jscodeshift -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/jscodeshift, .gemini/skills/jscodeshift, .github/skills/jscodeshift and .opencode/skills/jscodeshift in your project.

What does Jscodeshift need to run?

SKILL.md names no scripts, command-line tools or credentials: Jscodeshift is instructions for the agent only.

Does Jscodeshift access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Jscodeshift safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Jscodeshift use?

Jscodeshift is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Jscodeshift use?

About 1.8k tokens (SKILL.md is roughly 7.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 19k tokens, read only when the agent opens those files.

What are the alternatives to Jscodeshift?

Skills that share tags, products or a category with Jscodeshift: Convert Internal Package to TypeScript (TryGhost/Ghost, 55k stars), jscpd Code Migration Tracker (kucherenko/jscpd, 6.3k stars), ast-grep Codemod Reference (warp-drive-data/warp-drive, 3.2k stars) and Codemod (pmndrs/glyph, 392 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Jscodeshift?

pproenca (a GitHub user) maintains it in pproenca/dot-skills, which has 214 GitHub stars. The repository holds 182 skills in this directory. The repository was last updated on August 15, 2026.

Source: pproenca/dot-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Jscodeshift

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Facebook/Meta jscodeshift Best Practices

When to Apply

Rule Categories by Priority

Quick Reference

1. Parser Configuration (CRITICAL)

2. AST Traversal Patterns (CRITICAL)

3. Node Filtering (HIGH)

4. AST Transformation (HIGH)

5. Code Generation (MEDIUM)

6. Testing Strategies (MEDIUM)

7. Runner Optimization (LOW-MEDIUM)

8. Advanced Patterns (LOW)

How to Use

Full Compiled Document

Reference Files

Files

Compare with similar skills

Similar skills

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Related

Questions about Jscodeshift