# babel-traverse > babel-traverse maintains the overall tree state, and is responsible for replacing, removing, and adding nodes. ## Install ```sh $ npm install --save babel-traverse ``` ## Usage We can use it alongside Babylon to traverse and update nodes: ```js import * as babylon from "babylon"; import traverse from "babel-traverse"; const code = `function square(n) { return n * n; }`; const ast = babylon.parse(code); traverse(ast, { enter(path) { if (path.isIdentifier({ name: "n" })) { path.node.name = "x"; } } }); ``` [:book: **Read the full docs here**](https://github.com/thejameskyle/babel-handbook/blob/master/translations/en/plugin-handbook.md#babel-traverse)