Using Vale | Fern Documentation

Vale is an open-source linting tool that helps maintain consistent writing style and catch common errors in documentation.

Use Vale with your Fern docs to automatically check for style issues and enforce writing guidelines. Vale runs locally or in CI/CD to catch issues before they’re published.

Setup

Install Vale

Install Vale on your local machine.

Create a `.vale.ini` file in your repository root

Create a .vale.ini file and add the following to it so Vale parses MDX files as Markdown:

vale.ini

[formats]
mdx = md

Add style rules

Import existing Vale style packages or create your own style rules.

Check your docs

Check your entire documentation set, all pages in a directory, or a specific page:

$ vale fern/
> vale fern/pages/payments/
> vale fern/pages/payments/overview.mdx

Disable Vale for certain kinds of content

To disable Vale in specific sections of your Fern docs, use Vale comments wrapped in MDX syntax. This is particularly useful for code blocks, where Vale might flag variable names or code syntax as style violations.

Example Vale Usage

1 Vale will check this text.
2 
3 {/* <!-- vale off --> */}
4 
5 Vale won't check this text
6 
7 <CodeBlock>
8 ```typescript
9 import { PlantClient } from "@plantstore/sdk";
10 
11 const client = new PlantClient({ apiKey: "YOUR_API_KEY" });
12 const plant = await client.createPlant({
13   name: "Monstera",
14   species: "Monstera deliciosa"
15 });
16 ```
17 </CodeBlock>
18 
19 {/* <!-- vale on --> */}
20 
21 Vale will start checking this text again.

Automate Vale (optional)

Consider integrating Vale into your workflow so it runs automatically for all contributors:

GitHub Actions: Use the Vale Action to run Vale on pull requests and add inline comments on style issues
Pre-commit hooks: Use Vale’s pre-commit integration to check files before they’re committed

This helps enforce consistent style standards across your documentation team without requiring manual Vale runs.