package.json

The manifest file of a package. It contains all the package’s metadata, including dependencies, title, author, et cetera. This is a standard preserved across all major Node.JS package managers, including pnpm.

engines

You can specify the version of Node and pnpm that your software works on:

  1. {
  2.     "engines": {
  3.         "node": ">=10",
  4.         "pnpm": ">=3"
  5.     }
  6. }

During local development, pnpm will always fail with an error message if its version does not match the one specified in the engines field.

Unless the user has set the engine-strict config flag (see .npmrc), this field is advisory only and will only produce warnings when your package is installed as a dependency.

dependenciesMeta

Additional meta information used for dependencies declared inside dependencies, optionalDependencies, and devDependencies.

dependenciesMeta.*.injected

If this is set to true for a local dependency, the package will be hard linked to the modules directory, not symlinked.

For instance, the following package.json in a workspace will create a symlink to button in the node_modules directory of card:

  1. {
  2.   "name": "card",
  3.   "dependencies": {
  4.     "button": "workspace:1.0.0"
  5.   }
  6. }

But what if button has react in its peer dependencies? If all projects in the monorepo use the same version of react, then no problem. But what if button is required by card that uses react@16 and form with react@17? Without using inject, you’d have to choose a single version of react and install it as dev dependency of button. But using the injected field you can inject button to a package, and button will be installed with the react version of that package.

So this will be the package.json of card:

  1. {
  2.   "name": "card",
  3.   "dependencies": {
  4.     "button": "workspace:1.0.0",
  5.     "react": "16"
  6.   },
  7.   "dependenciesMeta": {
  8.     "button": {
  9.       "injected": true
  10.     }
  11.   }
  12. }

button will be hard linked into the dependencies of card, and react@16 will be symlinked to the dependencies of card/node_modules/button.

And this will be the package.json of form:

  1. {
  2.   "name": "form",
  3.   "dependencies": {
  4.     "button": "workspace:1.0.0",
  5.     "react": "17"
  6.   },
  7.   "dependenciesMeta": {
  8.     "button": {
  9.       "injected": true
  10.     }
  11.   }
  12. }

button will be hard linked into the dependencies of form, and react@17 will be symlinked to the dependencies of form/node_modules/button.

peerDependenciesMeta

This field lists some extra information related to the dependencies listed in the peerDependencies field.

peerDependenciesMeta.*.optional

If this is set to true, the selected peer dependency will be marked as optional by the package manager. Therefore, the consumer omitting it will no longer be reported as an error.

For example:

  1. {
  2.     "peerDependencies": {
  3.         "foo": "1"
  4.     },
  5.     "peerDependenciesMeta": {
  6.         "foo": {
  7.             "optional": true
  8.         },
  9.         "bar": {
  10.             "optional": true
  11.         }
  12.     }
  13. }

Note that even though bar was not specified in peerDependencies, it is marked as optional. pnpm will therefore assume that any version of bar is fine. However, foo is optional, but only to the required version specification.

publishConfig

It is possible to override some fields in the manifest before the package is packed. The following fields may be overridden:

To override a field, add the publish version of the field to publishConfig.

For instance, the following package.json:

  1. {
  2.     "name": "foo",
  3.     "version": "1.0.0",
  4.     "main": "src/index.ts",
  5.     "publishConfig": {
  6.         "main": "lib/index.js",
  7.         "typings": "lib/index.d.ts"
  8.     }
  9. }

Will be published as:

  1. {
  2.     "name": "foo",
  3.     "version": "1.0.0",
  4.     "main": "lib/index.js",
  5.     "typings": "lib/index.d.ts"
  6. }

publishConfig.executableFiles

By default, for portability reasons, no files except those listed in the bin field will be marked as executable in the resulting package archive. The executableFiles field lets you declare additional fields that must have the executable flag (+x) set even if they aren’t directly accessible through the bin field.

  1. {
  2.   "publishConfig": {
  3.     "executableFiles": [
  4.       "./dist/shim.js"
  5.     ]
  6.   }
  7. }

publishConfig.directory

You also can use the field publishConfig.directory to customize the published subdirectory relative to the current package.json.

It is expected to have a modified version of the current package in the specified directory (usually using third party build tools).

In this example the "dist" folder must contain a package.json

  1. {
  2.   "name": "foo",
  3.   "version": "1.0.0",
  4.   "publishConfig": {
  5.     "directory": "dist"
  6.   }
  7. }

publishConfig.linkDirectory

  • Default: true
  • Type: Boolean

When set to true, the project will be symlinked from the publishConfig.directory location during local development.

For example:

  1. {
  2.   "name": "foo",
  3.   "version": "1.0.0",
  4.   "publishConfig": {
  5.     "directory": "dist"
  6.     "linkDirectory": true
  7.   }
  8. }

pnpm.overrides

This field allows you to instruct pnpm to override any dependency in the dependency graph. This is useful to enforce all your packages to use a single version of a dependency, backport a fix, or replace a dependency with a fork.

Note that the overrides field can only be set at the root of the project.

An example of the "pnpm"."overrides" field:

  1. {
  2.   "pnpm": {
  3.     "overrides": {
  4.       "foo": "^1.0.0",
  5.       "quux": "npm:@myorg/quux@^1.0.0",
  6.       "bar@^2.1.0": "3.0.0",
  7.       "qar@1>zoo": "2"
  8.     }
  9.   }
  10. }

You may specify the package the overriden dependency belongs to by separating the package selector from the dependency selector with a “>”, for example qar@1>zoo will only override the zoo dependency of qar@1, not for any other dependencies.

An override may be defined as a reference to a direct dependency’s spec. This is achieved by prefixing the name of the dependency with a $:

  1. {
  2.   "dependencies": {
  3.     "foo": "^1.0.0"
  4.   },
  5.   "pnpm": {
  6.     "overrides": {
  7.       "foo": "$foo"
  8.     }
  9.   }
  10. }

The referenced package does not need to match the overridden one:

  1. {
  2.   "dependencies": {
  3.     "foo": "^1.0.0"
  4.   },
  5.   "pnpm": {
  6.     "overrides": {
  7.       "bar": "$foo"
  8.     }
  9.   }  
  10. }

pnpm.packageExtensions

The packageExtensions fields offer a way to extend the existing package definitions with additional information. For example, if react-redux should have react-dom in its peerDependencies but it has not, it is possible to patch react-redux using packageExtensions:

  1. {
  2.   "pnpm": {
  3.     "packageExtensions": {
  4.       "react-redux": {
  5.         "peerDependencies": {
  6.           "react-dom": "*"
  7.         }
  8.       }
  9.     }
  10.   }
  11. }

The keys in packageExtensions are package names or package names and semver ranges, so it is possible to patch only some versions of a package:

  1. {
  2.   "pnpm": {
  3.     "packageExtensions": {
  4.       "react-redux@1": {
  5.         "peerDependencies": {
  6.           "react-dom": "*"
  7.         }
  8.       }
  9.     }
  10.   }
  11. }

The following fields may be extended using packageExtensions: dependencies, optionalDependencies, peerDependencies, and peerDependenciesMeta.

A bigger example:

  1. {
  2.   "pnpm": {
  3.     "packageExtensions": {
  4.       "express@1": {
  5.         "optionalDependencies": {
  6.           "typescript": "2"
  7.         }
  8.       },
  9.       "fork-ts-checker-webpack-plugin": {
  10.         "dependencies": {
  11.           "@babel/core": "1"
  12.         },
  13.         "peerDependencies": {
  14.           "eslint": ">= 6"
  15.         },
  16.         "peerDependenciesMeta": {
  17.           "eslint": {
  18.             "optional": true
  19.           }
  20.         }
  21.       }
  22.     }
  23.   }
  24. }

package.json - 图1tip

Together with Yarn, we maintain a database of packageExtensions to patch broken packages in the ecosystem. If you use packageExtensions, consider sending a PR upstream and contributing your extension to the @yarnpkg/extensions database.

pnpm.peerDependencyRules

pnpm.peerDependencyRules.ignoreMissing

pnpm will not print warnings about missing peer dependencies from this list.

For instance, with the following configuration, pnpm will not print warnings if a dependency needs react but react is not installed:

  1. {
  2.   "pnpm": {
  3.     "peerDependencyRules": {
  4.       "ignoreMissing": ["react"]
  5.     }
  6.   }
  7. }

Package name patterns may also be used:

  1. {
  2.   "pnpm": {
  3.     "peerDependencyRules": {
  4.       "ignoreMissing": ["@babel/*", "@eslint/*"]
  5.     }
  6.   }
  7. }

pnpm.peerDependencyRules.allowedVersions

Unmet peer dependency warnings will not be printed for peer dependencies of the specified range.

For instance, if you have some dependencies that need react@16 but you know that they work fine with react@17, then you may use the following configuration:

  1. {
  2.   "pnpm": {
  3.     "peerDependencyRules": {
  4.       "allowedVersions": {
  5.         "react": "17"
  6.       }
  7.     }
  8.   }
  9. }

This will tell pnpm that any dependency that has react in its peer dependencies should allow react v17 to be installed.

It is also possible to suppress the warnings only for peer dependencies of specific packages. For instance, with the following configuration react v17 will be only allowed when it is in the peer dependencies of the button v2 package or in the dependencies of any card package:

  1. {
  2.   "pnpm": {
  3.     "peerDependencyRules": {
  4.       "allowedVersions": {
  5.         "button@2>react": "17",
  6.         "card>react": "17"
  7.       }
  8.     }
  9.   }
  10. }

pnpm.peerDependencyRules.allowAny

allowAny is an array of package name patterns, any peer dependency matching the pattern will be resolved from any version, regardless of the range specified in peerDependencies. For instance:

  1. {
  2.   "pnpm": {
  3.     "peerDependencyRules": {
  4.       "allowAny": ["@babel/*", "eslint"]
  5.     }
  6.   }
  7. }

The above setting will mute any warnings about peer dependency version mismatches related to @babel/ packages or eslint.

pnpm.neverBuiltDependencies

This field allows to ignore the builds of specific dependencies. The “preinstall”, “install”, and “postinstall” scripts of the listed packages will not be executed during installation.

An example of the "pnpm"."neverBuiltDependencies" field:

  1. {
  2.   "pnpm": {
  3.     "neverBuiltDependencies": ["fsevents", "level"]
  4.   }
  5. }

pnpm.onlyBuiltDependencies

A list of package names that are allowed to be executed during installation. If this field exists, only the listed packages will be able to run install scripts.

Example:

  1. {
  2.   "pnpm": {
  3.     "onlyBuiltDependencies": ["fsevents"]
  4.   }
  5. }

pnpm.allowedDeprecatedVersions

This setting allows muting deprecation warnings of specific packages.

Example:

  1. {
  2.   "pnpm": {
  3.     "allowedDeprecatedVersions": {
  4.       "express": "1",
  5.       "request": "*"
  6.     }
  7.   }
  8. }

With the above configuration pnpm will not print deprecation warnings about any version of request and about v1 of express.

pnpm.patchedDependencies

This field is added/updated automatically when you run pnpm patch-commit. It is a dictionary where the key should be the package name and exact version. The value should be a relative path to a patch file.

Example:

  1. {
  2.   "pnpm": {
  3.     "patchedDependencies": {
  4.       "express@4.18.1": "patches/express@4.18.1.patch"
  5.     }
  6.   }
  7. }

pnpm.allowNonAppliedPatches

When true, installation won’t fail if some of the patches from the patchedDependencies field were not applied.

  1. {
  2.   "pnpm": {
  3.     "patchedDependencies": {
  4.       "express@4.18.1": "patches/express@4.18.1.patch"
  5.     }
  6.     "allowNonAppliedPatches": true
  7. }

pnpm.updateConfig

pnpm.updateConfig.ignoreDependencies

Sometimes you can’t update a dependency. For instance, the latest version of the dependency started to use ESM but your project is not yet in ESM. Annoyingly, such a package will be always printed out by the pnpm outdated command and updated, when running pnpm update --latest. However, you may list packages that you don’t want to upgrade in the ignoreDependencies field:

  1. {
  2.   "pnpm": {
  3.     "updateConfig": {
  4.       "ignoreDependencies": ["load-json-file"]
  5.     }
  6.   }
  7. }

Patterns are also supported, so you may ignore any packages from a scope: @babel/*.

pnpm.auditConfig

pnpm.auditConfig.ignoreCves

A list of CVE IDs that will be ignored by the pnpm audit command.

  1. {
  2.   "pnpm": {
  3.     "auditConfig": {
  4.       "ignoreCves": [
  5.         "CVE-2022-36313"
  6.       ]
  7.     }
  8.   }
  9. }

pnpm.requiredScripts

Scripts listed in this array will be required in each project of the workspace. Otherwise, pnpm -r run <script name> will fail.

  1. {
  2.   "pnpm": {
  3.     "requiredScripts": ["build"]
  4.   }
  5. }

resolutions

Same as pnpm.overrides. We read it for easier migration from Yarn.