diff --git a/addons/api/addon/adapters/application.js b/addons/api/addon/adapters/application.js
index a64f443bc..3fb95fda9 100644
--- a/addons/api/addon/adapters/application.js
+++ b/addons/api/addon/adapters/application.js
@@ -5,6 +5,13 @@ import { get } from '@ember/object';
 export default class ApplicationAdapter extends RESTAdapter {
   // =attributes
 
+  /**
+   * Sets host to the `api.host` string in the application's config,
+   * if set.
+   * @type {string}
+   */
+  host = get(config, 'api.host');
+
   /**
    * Sets namespace to the `api.namespace` string in the application's config,
    * if set.
diff --git a/addons/api/tests/dummy/config/environment.js b/addons/api/tests/dummy/config/environment.js
index b073014e3..914dad3be 100644
--- a/addons/api/tests/dummy/config/environment.js
+++ b/addons/api/tests/dummy/config/environment.js
@@ -23,7 +23,8 @@ module.exports = function (environment) {
     },
 
     api: {
-      namespace: '/api/addon/v1',
+      host: '',
+      namespace: 'v1',
     },
   };
 
diff --git a/ui/core/README.md b/ui/core/README.md
index 84d20145c..5bfdb86b4 100644
--- a/ui/core/README.md
+++ b/ui/core/README.md
@@ -72,6 +72,7 @@ These environment variables may be used to customized the build.
 | Variable | Default Value | Description |
 | -------- | ------------- | ----------- |
 | `APP_NAME` | Application Name | The user-facing name of the application, appearing in titles, etc. |
+| `API_HOST` | | The host of the API, if different than UI (e.g. https://example.net:1234). |
 
 ### Running Tests
 
diff --git a/ui/core/config/environment.js b/ui/core/config/environment.js
index 1f58b0d53..865c26a02 100644
--- a/ui/core/config/environment.js
+++ b/ui/core/config/environment.js
@@ -1,6 +1,7 @@
 'use strict';
 
 const APP_NAME = process.env.APP_NAME || 'Application Name';
+const API_HOST = process.env.API_HOST || 'http://localhost:9200';
 
 module.exports = function (environment) {
   let ENV = {
@@ -26,6 +27,7 @@ module.exports = function (environment) {
     },
 
     api: {
+      host: API_HOST,
       namespace: 'v1',
     },
 
@@ -71,6 +73,11 @@ module.exports = function (environment) {
     };
 
     enableUnsafeCSP();
+    // TODO: should provide an env var to explicitly add a host to CSP
+    // at build time for any environment (not just development),
+    // rather than automatically include API_HOST.  Changes to CSP should
+    // be explicit.
+    if (API_HOST) ENV.contentSecurityPolicy['connect-src'].push(API_HOST);
   }
 
   if (environment === 'test') {
diff --git a/ui/core/mirage/config.js b/ui/core/mirage/config.js
index 7fae775bc..323eca350 100644
--- a/ui/core/mirage/config.js
+++ b/ui/core/mirage/config.js
@@ -21,5 +21,8 @@ export default function() {
     https://www.ember-cli-mirage.com/docs/route-handlers/shorthands
   */
 
+  if (config.api.host) this.passthrough(`${config.api.host}/**`);
+  this.passthrough();
+
   this.get('/orgs/:org_id/projects');
 }