# Environment Variables Environment variables defined on the Keycloak server can be transferred to the theme. This allows for a degree of theme customization without necessitating a rebuild. This approach is particularly useful if multiple parties are reusing your theme. As an example, you can distribute a single .jar file to multiple customers, enabling them to modify certain aspect of the login page by defining specific environment variables. Concretely the ide is to be able, if you start your Keycloak server like this:

docker run \
    -e KEYCLOAK_ADMIN=admin \
    -e KEYCLOAK_ADMIN_PASSWORD=admin \
    --env MY_ENV_VARIABLE='Value of my env variable' \
    -p 8080:8080 \
    docker-keycloak-with-theme

To be able to access MY\_ENV\_VARIABLE value in your theme. (This is assuming you're using docker but for for Helm for example see [this](/keycloakify/v9/importing-your-theme-in-keycloak.md#using-helm)). To implement this you need to use [the extraThemeProperties build option](/keycloakify/v9/build-options.md#extrathemeproperties) like so: {% tabs %} {% tab title="Vite" %}

import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'
import { keycloakify } from "keycloakify/vite-plugin";

export default defineConfig({
  plugins: [
    react(), 
    keycloakify({
      extraThemeProperties: [ 
        "MY_ENV_VARIABLE=${env.MY_ENV_VARIABLE:default}"
      ]
    })
  ],
})

{% endtab %} {% tab title="Webpack" %}

{
    "keycloakify": {
        "extraThemeProperties": [ 
            "MY_ENV_VARIABLE=${env.MY_ENV_VARIABLE:default}"
        ]
    }
}

{% endtab %} {% endtabs %} Then you will be able to access the value of MY\_ENV\_VARIABLE with kcContext.properties.MY\_ENV\_VARIABLE. Example: {% code title="login/Template.tsx" %} ```tsx import { useEffect } from "react"; import { type TemplateProps } from "keycloakify/login/TemplateProps"; import type { KcContext } from "./kcContext"; import type { I18n } from "./i18n"; export default function Template(props: TemplateProps) { const { kcContext } = props; useEffect(() => { console.log(kcContext.properties.MY_ENV_VARIABLE); }, []); //... } ``` {% endcode %} You also probably want to provide mock values the variables for when you're developing your theme in Storybook:

import { createGetKcContext } from "keycloakify/login";

export const { getKcContext } = createGetKcContext({
  mockData: [ /* ... */],
  mockProperties: {
    MY_ENV_VARIABLE: "Mocked value"
  }
});

export const { kcContext } = getKcContext({
  // Uncomment to test the login page for development.
  //mockPageId: "login.ftl",
});

export type KcContext = NonNullable<ReturnType<typeof getKcContext>["kcContext"]>;

--- # 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://docs.keycloakify.dev/keycloakify/v9/environment-variables.md?ask= ``` 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.