> For the complete documentation index, see [llms.txt](https://gofast.disasm.dev/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gofast.disasm.dev/readme.md).

# Welcome to go-fAST

**go-fAST** is a high-performance JavaScript parsing and transformation toolkit written in Go. It allows you to parse JavaScript code into Abstract Syntax Trees (ASTs), analyze them, and transform them efficiently.

> Think of it as a fast, lightweight alternative to Babel — with Go speed and simplicity.

GitHub Repository: <https://github.com/T14Raptor/go-fAST>

***

### 🚀 Key Features

* **Ultra-fast JavaScript parsing**
* **AST manipulation support**
* **Code generation from ASTs**
* **Depth-first AST traversal**
* **Visitor pattern implementation**
* Designed for **performance and simplicity**, on par with tools like [SWC](https://swc.rs/)
* Built-in scope tracking (use `resolver.Resolve()` for this). See [resolver](/built-in-visitors/resolver.md)

***

### ⚠️ Important Differences

go-fAST is designed with **performance and minimalism** in mind. It avoids many features and abstractions common in heavyweight JavaScript tooling:

#### ❌ Not Included:

* No parent, sibling, or reference maps on nodes
* No automated mutation helpers

This leads to:

* Faster parse and traversal times
* Easier reasoning about node transformations
* Explicit and transparent AST control


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://gofast.disasm.dev/readme.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.