The default I use with new Trellis/Bedrock Wordpres projects

composer.json

{
  "name": "roots/bedrock",
  "type": "project",
  "license": "MIT",
  "description": "WordPress boilerplate with modern development tools, easier configuration, and an improved folder structure",
  "homepage": "https://roots.io/bedrock/",
  "authors": [
    {
      "name": "Scott Walkinshaw",
      "email": "scott.walkinshaw@gmail.com",
      "homepage": "https://github.com/swalkinshaw"
    },
    {
      "name": "Ben Word",
      "email": "ben@benword.com",
      "homepage": "https://github.com/retlehs"
    }
  ],
  "keywords": [
    "bedrock",
    "composer",
    "roots",
    "wordpress",
    "wp",
    "wp-config"
  ],
  "support": {
    "issues": "https://github.com/roots/bedrock/issues",
    "forum": "https://discourse.roots.io/category/bedrock"
  },
  "repositories": [
    {
      "type": "package",
      "package": {
        "name": "magneticmule/wp-publish-webhook",
        "type": "wordpress-plugin",
        "version": "1.0.0",
        "dist": {
          "type": "zip",
          "url": "https://github.com/MagneticMule/wp-publish-webhook/archive/master.zip"
        }
      }
    },
    {
      "type": "package",
      "package": {
        "name": "hrsetyono/wp-sync-db",
        "type": "wordpress-plugin",
        "version": "1.7.0",
        "dist": {
          "type": "zip",
          "url": "https://github.com/hrsetyono/wp-sync-db/archive/1.7.0.zip"
        }
      }
    },
    {
      "type": "package",
      "package": {
        "name": "wp-sync-db/wp-sync-db-media-files",
        "type": "wordpress-plugin",
        "version": "1.7.0",
        "dist": {
          "type": "zip",
          "url": "https://github.com/hrsetyono/wp-sync-db/archive/1.7.0.zip"
        }
      }
    },
    {
      "type": "composer",
      "url": "https://wpackagist.org"
    }
  ],
  "require": {
    "php": ">=7.1",
    "composer/installers": "^1.7",
    "vlucas/phpdotenv": "^3.4.0",
    "oscarotero/env": "^1.2.0",
    "roots/wordpress": "5.2.3",
    "roots/wp-config": "1.0.0",
    "roots/wp-password-bcrypt": "1.0.0",
    "magneticmule/wp-publish-webhook": "*",
    "hrsetyono/wp-sync-db": "*",
    "wpackagist-plugin/advanced-custom-fields": "5.8.7",
    "wpackagist-plugin/acf-to-rest-api": "3.1.0",
    "wpackagist-plugin/wp-rest-api-menus": "dev-trunk",
    "wpackagist-plugin/wp-mail-smtp": "dev-trunk",
    "wpackagist-plugin/unconfirmed": "dev-trunk",
    "wpackagist-plugin/better-wp-security": "dev-trunk"
  },
  "require-dev": {
    "squizlabs/php_codesniffer": "^3.4.2",
    "roave/security-advisories": "dev-master"
  },
  "config": {
    "optimize-autoloader": true,
    "preferred-install": "dist",
    "sort-packages": true
  },
  "minimum-stability": "dev",
  "prefer-stable": true,
  "extra": {
    "installer-paths": {
      "web/app/mu-plugins/{$name}/": [
        "type:wordpress-muplugin"
      ],
      "web/app/plugins/{$name}/": [
        "type:wordpress-plugin"
      ],
      "web/app/themes/{$name}/": [
        "type:wordpress-theme"
      ]
    },
    "wordpress-install-dir": "web/wp"
  },
  "scripts": {
    "post-root-package-install": [
      "php -r \"copy('.env.example', '.env');\""
    ],
    "test": [
      "phpcs"
    ]
  }
}