# Dump Ast > Parse JS code through OXC and display ESTree JSON AST. Use proactively when implementing codegen, transforms, or debugging to understand how OXC represents a specific JS/TS construct in its AST. MUST use this skill before writing any new AST node construction in builder.rs, before implementing a new codegen visitor, or when unsure how OXC represents a JS pattern (destructuring, spread, optional chaining, etc.). Also use when debugging AST mismatch issues or when porting a new Svelte feature that involves JS expression handling. Use when this capability is needed. - Skill: `tomevault-io/dump-ast` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/dump-ast` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/dump-ast/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Web & Frontend - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/dump-ast --- # Dump OXC AST: $ARGUMENTS Parses JavaScript through OXC and displays ESTree-compatible JSON AST. ## Step 1: Parse ``` just dump-ast '$ARGUMENTS' ``` ## Step 2: Display Show the JSON output. If parsing fails: - Wrap in parentheses if OXC expects a statement: `($ARGUMENTS)` - Try as module-level code if it's a declaration ## When to use proactively Use this skill whenever you need to understand how OXC represents a specific JS construct — for example when implementing codegen, writing transforms, or debugging parser output mismatches. --- > Source: [MrWaip/svelte-rs-2](https://github.com/MrWaip/svelte-rs-2) — distributed by [TomeVault](https://tomevault.io).