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README.md

@@ -40,3 +40,52 @@ const config = envoose.getConfig(configSchema)
 
 module.exports = config
 ```
+
+## Docs
+
+### envoose.getConfig(configSchema)
+
+Validate and load configs object using configSchema
+
+### ConfigSchema
+
+A configSchema is an object that tells envoose which env vars to load and how to load them, in its most basic form, it's just a set of keys to load
+
+```js
+const configSchema = {
+  FIRST_KEY: {},
+  SECOND_KEY: {}
+}
+```
+
+#### Options
+
+##### required
+A required key must be supplied through env vars. If the value is not available in `process.env`, `getConfig` will throw `ConfigValidationError`.
+
+Note that `default` and `required` can't be combined.
+
+##### default
+A value to fallback to if the env var is not set.
+
+##### env
+By default the config is read from env var with the same name as the config name. If `env` is supplied, it will read from that env var instead.
+
+##### type
+Env vars are strings by default, however envoose allows you to cast them to different data types.
+
+###### Supported Types
+- `String` (default)
+- `Number`
+- `Date`
+- `Boolean` ('true', 'yes', '1' evaluate to true, while 'false', 'no', '0' evaluate to false, `CastError` will be thrown otherwise)
+- Custom types by supplying a mapping function (ex: array of numbers `s => s.split(',').map(Number)`)
+
+##### enum
+Built in validator that checks whether the value falls in one of the values in the list. Throws `ConfigValidationError` if not found in enum.
+
+##### match
+Built in validator that checks whether the value matches this regex or not. Throws `ConfigValidationError` if not matched.
+
+##### validator
+Accepts custom validation function that should return true if valid and false otherwise.