npm command-line interface

# npm-patch @12.0.0

Apply local patches to installed dependencies

## Table of contents

- See Also

### Synopsis

    npm patch <pkg>[@<version>]
    npm patch add <pkg>[@<version>] [--edit-dir <path>] [--ignore-existing]
    npm patch commit <edit-dir> [--patches-dir <dir>] [--keep-edit-dir]
    npm patch update <pkg>[@<old-version>] [--to <new-version>] [--patches-dir <dir>]
    npm patch ls
    npm patch rm <pkg>[@<version>]

Note: This command is unaware of workspaces.

### Description

`npm patch` lets you apply small, local modifications to an installed dependency and have them re-applied automatically on every install. Patches are declared in the `patchedDependencies` field of your root `package.json`, stored as plain unified diffs under the `patches/` directory, and recorded with a content hash in `package-lock.json`.

Because patches are applied during the install itself, they work regardless of `install-strategy`, apply to transitive dependencies, and are not disabled by `--ignore-scripts`.

The bare form `npm patch <pkg>` is shorthand for `npm patch add <pkg>`. A package literally named like a subcommand must use the explicit form, e.g. `npm patch add add`.

- `npm patch add <pkg>[@<version>]`

  Prepares a package for editing. npm extracts a clean copy of the resolved package tarball into a temporary directory outside `node_modules` and prints its path. Edit the files there, then run `npm patch commit`.

  If more than one version of `<pkg>` is installed, re-run with an exact selector such as `npm patch add lodash@4.17.21`.

- `npm patch commit <edit-dir>`

  Diffs the edited directory against a clean copy of the original tarball, writes the unified diff to `<patches-dir>/<name>@<version>.patch`, adds the entry to `patchedDependencies`, and updates `package-lock.json`.

- `npm patch ls`

  Lists registered patches and how many installed nodes each one matches.

- `npm patch rm <pkg>[@<version>]`

  Removes the matching entries from `patchedDependencies`, deletes the patch file when no other entry references it, and updates `package-lock.json`. If `<version>` is omitted, all entries for `<pkg>` are removed.

### Failure modes

By default any patch problem is a hard error that aborts the install: a patch that fails to apply, a registered patch that matches no installed package, a missing patch file, or a patch whose hash does not match the lockfile.

Two CLI-only flags relax this for one-off cases: `--allow-unused-patches` and `--ignore-patch-failures`.

### Configuration

#### `patches-dir`

- Default: "patches"
- Type: String

The directory, relative to the project root, where `npm patch commit` writes patch files for `patchedDependencies`.

#### `allow-unused-patches`

- Default: false
- Type: Boolean

Install even when a registered patch in `patchedDependencies` matches no installed package. Does not silence patch apply failures.

This flag is only honored when passed on the command line; it is ignored in `.npmrc` and environment variables, and rejected by `npm ci`.

#### `ignore-patch-failures`

- Default: false
- Type: Boolean

Install even when a registered patch fails to apply, with a warning per failure. Intended for incident response only.

This flag is only honored when passed on the command line; it is ignored in `.npmrc` and environment variables, and rejected by `npm ci`.

#### `edit-dir`

- Default: null
- Type: null or Path

Override the temporary directory used by `npm patch add` to prepare a package for editing.

#### `ignore-existing`

- Default: false
- Type: Boolean

With `npm patch add`, discard a previous unfinished edit directory and start fresh.

#### `keep-edit-dir`

- Default: false
- Type: Boolean

With `npm patch commit`, do not remove the edit directory after committing the patch.

#### `to`

- Default: null
- Type: null or String

Used by `npm patch update` to set the version to rebase a patch onto when it cannot be read from `package-lock.json` — for example an exact-version selector, or a version that has not been installed yet.

#### `registry`

- Default: "https://registry.npmjs.org/"
- Type: URL

The base URL of the npm registry.

## See Also

- npm install
- npm ci
- package-lock.json
- config