Code Formatting Reference

Nx formats code when you run nx format:write or nx format:check and at the end of most generators and migrations. All of them use the same formatter, which Nx detects from your workspace.

Two formatters are supported: oxfmt and Prettier. Prettier is the default wherever workspace creation asks which one to use, and oxfmt is offered as experimental while it is pre-1.0.

How Nx picks a formatter

Detection runs in this order, and the first match wins:

1. An oxfmt config file exists at the workspace root.
2. A Prettier config file exists at the workspace root, or package.json has a prettier key.
3. package.json declares an oxfmt dependency.
4. package.json declares a prettier dependency.

Steps 3 and 4 read the root package.json only. A formatter that reaches node_modules as a transitive dependency doesn't count.

If nothing matches, nx format:write and nx format:check warn and exit 0, and generators skip formatting.

The oxfmt config files Nx looks for:

• .oxfmtrc.json
• .oxfmtrc.jsonc
• oxfmt.config.ts
• oxfmt.config.mts

When both are configured

oxfmt wins, and Nx warns once so the switch is not silent. Adding an .oxfmtrc.json to a workspace that already has a .prettierrc switches the whole workspace over, including generator formatting. To go back, delete the oxfmt config.

Switch an existing workspace to oxfmt

npm add -D oxfmt

.oxfmtrc.json

{
  "singleQuote": true,
  "printWidth": 80
}

These match an Nx-generated .prettierrc. If you wrote your own, match what it set instead. oxfmt defaults to double quotes and a width of 100.

oxfmt also sorts package.json keys, which Prettier does not. Expect every manifest in the workspace to be reordered on the first run. Set "sortPackageJson": false in .oxfmtrc.json to keep your current order.

Then delete .prettierrc and run nx format:write --all to reformat everything in one commit.

Keep .prettierignore if you have one. oxfmt reads it too, so deleting it starts formatting files you had excluded.

Generator formatting and nx format differ

nx format:write runs the formatter's own CLI. Generators format files that exist only in memory, so Nx applies the configuration itself. With oxfmt, both resolve from each file's own directory upwards: the nearest oxfmt config, its overrides and ignorePatterns, and every .gitignore and .prettierignore along the way. With Prettier, both read the root ignore files only, so a nested .prettierignore has no effect either way.

A nested oxfmt config replaces the one above it rather than merging with it, so any option it leaves out falls back to the oxfmt default and not to the parent's value.

.editorconfig is the exception. oxfmt looks it up once from the directory it runs in rather than from each file upwards. For nx format that directory is the one you run the command from; generators anchor the lookup at the workspace root, so a nested .editorconfig never affects generated files. The lookup walks up until a file sets root = true, so a checkout containing your workspace can contribute settings.

A root .editorconfig that sets indent_size without indent_style also leaves the two disagreeing. Generator formatting applies it and nx format:write ignores it, so your generated files fail your own nx format:check. Set indent_style alongside it.

Skip formatting

Set NX_SKIP_FORMAT=true to stop generators and migrations from formatting. It also covers the files nx init and nx import write, and the formatting pass at the end of create-nx-workspace. TypeScript path sorting is separate and stays off by default. Turn it on with NX_FORMAT_SORT_TSCONFIG_PATHS=true, or per call with formatFiles' sortRootTsconfigPaths option.

NX_SKIP_FORMAT=true nx g @nx/react:app my-app

Choose a formatter at workspace creation

create-nx-workspace asks which formatter you want on every preset that sets one up: a stack (React, Vue, Angular, or Node), web-components, the TypeScript monorepo, and ts-standalone. Whether the workspace uses package manager workspaces makes no difference. The apps and npm presets generate no project, so they set up no formatter unless you pass --formatter, and neither does @nx/workspace:new run directly. Pass --formatter on any path to choose explicitly:

npx create-nx-workspace@latest my-workspace --formatter=prettier

The accepted values are oxfmt, prettier, and none.