Configuration

Oxfmt works out of the box, but most teams commit a configuration file to keep formatting consistent across local runs, editors, and CI.

This page focuses on project configuration: formatting options, ignore patterns, and experimental features.

Create a config file

To generate a starter config in the current directory:

oxfmt --init

Oxfmt automatically looks for .oxfmtrc.json or .oxfmtrc.jsonc starting from the current directory and walking up the tree. You can also pass a config explicitly:

oxfmt -c path/to/yourconfig.json

A minimal configuration looks like this:

.oxfmtrc.json

{
  "$schema": "./node_modules/oxfmt/configuration_schema.json",
  "printWidth": 80
}

Configuration file format

A configuration file is a JSON object. The most common top-level fields are:

• printWidth: Line width limit (default: 100)
• tabWidth: Spaces per indentation level (default: 2)
• useTabs: Use tabs instead of spaces (default: false)
• semi: Add semicolons (default: true)
• singleQuote: Use single quotes (default: false)
• trailingComma: Trailing commas in multi-line structures (default: "all")
• ignorePatterns: Glob patterns to exclude from formatting
• experimentalSortImports: Configure import sorting (disabled by default)
• experimentalSortPackageJson: Configure package.json sorting (enabled by default)
• experimentalTailwindcss: Configure Tailwind class sorting (disabled by default)

For a complete list of fields, see the Config file reference.

JSON schema

Add a $schema field for editor validation and autocomplete:

.oxfmtrc.json

{
  "$schema": "./node_modules/oxfmt/configuration_schema.json"
}

.editorconfig

Oxfmt reads these .editorconfig properties:

• end_of_line → endOfLine
• indent_style → useTabs
• indent_size → tabWidth
• max_line_length → printWidth
• insert_final_newline → insertFinalNewline

Both root section and glob-based overrides are supported.

[*]
indent_size = 4

[*.{js,ts}]
indent_size = 2

Oxfmt uses only the nearest .editorconfig from the current directory:

• root = true is not respected
• Nested .editorconfig files are not merged

Precedence

Options are applied in order (lowest to highest priority):

1. Defaults
2. .oxfmtrc.json(c) root options
3. .oxfmtrc.json(c) overrides options
4. fallback to options supported by .editorconfig for unset fields

Oxfmt-specific options

insertFinalNewline

Controls whether a final newline is added to formatted files. Defaults to true.

This is a frequently requested Prettier feature, as some environments (e.g., Salesforce) strip trailing newlines.

printWidth

Oxfmt defaults to printWidth: 100 (Prettier uses 80). Reasons:

• TypeScript code is longer due to type annotations
• Import statements often have many specifiers
• Modern screens are wider
• Fewer line breaks mean fewer LLM tokens

To match Prettier's default:

.oxfmtrc.json

{
  "printWidth": 80
}

Next steps

• Ignore files: Ignore files and patterns, .gitignore and .prettierignore workflows.
• Inline ignore comments: Inline suppressions for specific code.
• Config file reference: Full schema and field documentation.
• CLI reference: Complete list of flags.