# Configuration Options > Environment variables are used for all configuration within a Directus project. These variables can be defined in a > number of ways, which we cover below. ## Configuration Files By default, Directus will read the `.env` file located next to your project's `package.json` (typically in the root folder of your project) for its configuration. You can change this path and filename by setting the `CONFIG_PATH` environment variable before starting Directus. For example: ```bash CONFIG_PATH="/path/to/config.js" npx directus start ``` In case you prefer using a configuration file instead of environment variables, you can also use the `CONFIG_PATH` environment variable to instruct Directus to use a local configuration file instead of environment variables. The config file can be one of the following formats: - [.env](#env) - [config.json](#configjson) - [config.yaml](#configyaml) - [config.js](#configjs) ### .env If the config path has no file extension, or a file extension that's not one of the other supported formats, Directus will try reading the file config path as environment variables. This has the following structure: ```text HOST="0.0.0.0" PORT=8055 DB_CLIENT="pg" DB_HOST="localhost" DB_PORT=5432 etc ``` ### config.json If you prefer a single JSON file for your configuration, create a JSON file with the environment variables as keys, for example: ```text CONFIG_PATH="/path/to/config.json" ``` ```json { "HOST": "0.0.0.0", "PORT": 8055, "DB_CLIENT": "pg", "DB_HOST": "localhost", "DB_PORT": 5432 // etc } ``` ### config.yaml Similar to JSON, you can use a `.yaml` (or `.yml`) file for your config: ```text CONFIG_PATH="/path/to/config.yaml" ``` ```yaml HOST: 0.0.0.0 PORT: 8055 DB_CLIENT: pg DB_HOST: localhost DB_PORT: 5432 # # etc ``` ### config.js Using a JavaScript file for your config allows you to dynamically generate the configuration of the project during startup. By default, the file is expected to be a ESM, while CommonJS is supported too by using `.cjs` as the file extension. The JavaScript configuration supports two different formats, either an **Object Structure** where the key is the environment variable name: ```js [config.js] export default { HOST: "0.0.0.0", PORT: 8055, DB_CLIENT: "pg", DB_HOST: "localhost", DB_PORT: 5432, // etc }; ``` ```js [config.cjs] module.exports = { HOST: "0.0.0.0", PORT: 8055, DB_CLIENT: "pg", DB_HOST: "localhost", DB_PORT: 5432, // etc }; ``` Or a **Function Structure** that *returns* the same object format as above. The function gets `process.env` as its parameter. ```js [config.js] export default function (env) { return { HOST: "0.0.0.0", PORT: 8055, DB_CLIENT: "pg", DB_HOST: "localhost", DB_PORT: 5432, // etc }; } ``` ```js [config.cjs] module.exports = function (env) { return { HOST: "0.0.0.0", PORT: 8055, DB_CLIENT: "pg", DB_HOST: "localhost", DB_PORT: 5432, // etc }; }; ``` ## Environment Variable Files Any of the environment variable values can be imported from a file, by appending `_FILE` to a [Directus environment variable name](https://github.com/directus/directus/blob/main/packages/env/src/constants/directus-variables.ts). This is especially useful when used in conjunction with Docker Secrets, so you can keep sensitive data out of your compose files. For example: ```text DB_PASSWORD_FILE="/run/secrets/db_password" ``` ## Type Casting and Nesting Environment variables are automatically type cast based on the structure of the variable, for example: ```text PUBLIC_URL="https://example.com" // "https://example.com" DB_HOST="3306" // 3306 CORS_ENABLED="false" // false STORAGE_LOCATIONS="s3,local,example" // ["s3", "local", "example"] ``` In cases where the environment variables are converted to a configuration object for third party library use, like in `DB_*` or `REDIS_*`, the environment variable will be converted to camelCase. You can use a double underscore (`__`) for nested objects: ```text DB_CLIENT="pg" DB_CONNECTION_STRING="postgresql://postgres:example@127.0.0.1" DB_SSL__REJECT_UNAUTHORIZED="false" { client: "pg", connectionString: "postgresql://postgres:example@127.0.0.1", ssl: { rejectUnauthorized: false } } ``` ## Environment Syntax Prefix Directus will attempt to [automatically type cast environment variables](#type-casting-and-nesting) based on context clues. If you have a specific need for a given type, you can tell Directus what type to use for the given value by prefixing the value with `{type}:`. The following types are available:
Syntax Prefix Example Output
string string:value "value"
number number:3306 3306
regex regex:\.example\.com$ /\.example\.com$/
array array:https://example.com,https://example2.com
array:string:https://example.com,regex:\.example3\.com$ 		["https://example.com", "https://example2.com"]
["https://example.com", /\.example3\.com$/]
json json:{"items": ["example1", "example2"]} {"items": ["example1", "example2"]}
Explicit casting is also available when reading from a file with the `_FILE` suffix. ## Environment Object Syntax Environment variables that end on a `*` in our docs allow you to configure internal objects with the following notation. For the variable `MY_ENV_*`: - `MY_ENV_SIZE=1` will be turned into `{ size: 1 }` - `MY_ENV_MAX_LENGTH=1` will be turned into `{ maxLength: 1 }` - `MY_ENV_BRAND__COLOR=red` will be turned into `{ brand: {color: 'red'} }` - `MY_ENV_BRAND__FONT_SIZE=18px` and `MY_ENV_BRAND__FONT=arial` will be turned into `{ brand: { fontSize: '18px', font: 'arial' } }`