diff --git a/README.md b/README.md
index 8a191d83..5afe063b 100644
--- a/README.md
+++ b/README.md
@@ -207,8 +207,31 @@ $ node_modules/.bin/babel-node src/scripts/fetchStatsFromGA.js
 
 ### Pulling administrative commands from Google Pub/Sub
 
+#### Setup
+
+Please use the following command to set up the Pub/Sub topic and subscription, with a Google cloud account with sufficient permissions:
+
+```
+# Setup ADMIN_PUBSUB_TOPIC
+# You can change topic to your need.
+export ADMIN_PUBSUB_TOPIC=rumors-api-commands
+
+# Create a Pub/Sub topic
+gcloud pubsub topics create $ADMIN_PUBSUB_TOPIC --schema=${}
+
+# Create a Pub/Sub subscription
+gcloud pubsub subscriptions create ${ADMIN_PUBSUB_TOPIC}-subscription --topic=${ADMIN_PUBSUB_TOPIC}
+```
+
+Remember to update `ADMIN_PUBSUB_TOPIC` in `.env` and in runtime environment.
+
+#### Runtime config
+
 When API server starts up, it will link to Google Pub/Sub topic if and only if env var `ADMIN_PUBSUB_TOPIC` is set, using [Application Default Credentials](https://cloud.google.com/docs/authentication/application-default-credentials).
 
+The service account behind the key in previous step should have the following [minimum roles](https://cloud.google.com/pubsub/docs/access-control#iam_roles):
+  - `Pub/Sub Subscriber` on the GCP project
+
 ### Removing article-reply from database
 -  To set an article-reply to deleted state on production, run:
 ```
diff --git a/src/commandListener.ts b/src/commandListener.ts
index b14894e5..3ab62545 100644
--- a/src/commandListener.ts
+++ b/src/commandListener.ts
@@ -1,3 +1,14 @@
-type T = { foo: number };
+async function main() {
+  if (!process.env.ADMIN_PUBSUB_TOPIC) {
+    console.info(
+      '[command-listener] `ADMIN_PUBSUB_TOPIC` is not set, exiting...'
+    );
+    process.exit(0);
+  }
 
-console.log('commandServer.ts');
+  /**
+   * Subscribe to specified topics
+   */
+}
+
+main().catch(err => console.error('[command-listener]', err));
diff --git a/tsconfig.json b/tsconfig.json
index 3cb046ba..bdab40b0 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -7,6 +7,7 @@
     "noEmit": true,
     "esModuleInterop": true,
     "module": "esnext",
+    "target": "ESNext",
     "moduleResolution": "node",
     "resolveJsonModule": true,
     "isolatedModules": true