# Env Var Overrides

Every [Config Setting](/the-basics/config-items.md) can be overridden by convention by creating environment variables in the shell where you run `box`. This is ideal for Docker containers or CI builds where you want to easily set one-off settings and not require an entire JSON file. You can set these as actual environment variables or [Java system properties of the CLI](https://commandbox.ortusbooks.com/usage/execution#ad-hoc-java-properties-for-the-cli). Env vars are loaded AFTER any `.cfconfig.json` files have been loaded by convention and will override any settings in the JSON. They are not case-sensitive.

The variable must start with the text `cfconfig_` and will be followed by the name of the setting.

```bash
cfconfig_adminPassword=myPass
```

For nested settings inside a struct or array, you can use underscores to represent dots. Note the following will error if there is not already a datasource named `myDSN` in the server.

```bash
cfconfig_datasources_myDSN_password=myPass
```

The overrides are applied using the same mechanism that the `cfconfig set` command uses, which means you can also pass JSON directly for complex values.

```bash
# JSON which will be parsed
cfconfig_mailServers=[{"port":"25","smtp":"localhost2"}]
```

On OS's like Windows which allow for any manner of special characters, you can provide any string which would also be valid for the `config set` command. Ex:

```bash
# dot-delimited keys
cfconfig_datasources.myDSN.password=myPass
# array indexes too
cfconfig_mailServers[1].smtp=mail.server.com
```

When you provide JSON, the `append` flag will be set to true when adding the configuration to what's already in CommandBox.

Overridden env vars will **not** be written to any `.cfconfig.json` file and will be lost when box stops. They will also take precedence and override any explicit settings already set.

## Target a Lucee/Railo specific server/web context

If you want to specify a setting via an env var that targets a web context, you can use the following conventions:

```bash
# Default (server context)
cfconfig_requestTimeout=...

# Force web context.  (On adobe, just loaded normally)
cfconfig_web_requestTimeout=...

# Force server context- same as default. (On adobe, just loaded normally)
cfconfig_server_requestTimeout=...
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://cfconfig.ortusbooks.com/using-the-cli/env-var-overrides.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.