diff --git a/.prettierrc.json b/.prettierrc.json
index 91a3517..a16ffc6 100644
--- a/.prettierrc.json
+++ b/.prettierrc.json
@@ -1,3 +1,3 @@
 {
-  "printWidth": 160
+  "printWidth": 230
 }
diff --git a/README.md b/README.md
index b0fcfb8..8d8a13f 100644
--- a/README.md
+++ b/README.md
@@ -66,7 +66,7 @@
 ## Can you hear me, Major Tom?
 
 Push notifications server for bitcoin wallets. Processes blocks & mempool in search of subscribed onchain addresses.
-Built with typescript, expressjs, mariadb & openapi.
+Built with typescript, expressjs, mariadb & [openapi](https://editor.swagger.io/?url=https://raw.githubusercontent.com/BlueWallet/GroundControl/master/openapi.yaml).
 
 In memory of David Bowie
 
@@ -92,6 +92,7 @@ Set them as env variables or put them into `.env` file in project root dir.
 - `FCM_SERVER_KEY` hex encoded
 - `APNS_PEM` hex encoded
 - `BITCOIN_RPC` for example `http://username:password@host:8332`
+- `APNS_TOPIC` for example `io.bluewallet.bluewallet`
 
 ### License
 
diff --git a/openapi.yaml b/openapi.yaml
index b18f1d5..269613f 100644
--- a/openapi.yaml
+++ b/openapi.yaml
@@ -5,6 +5,8 @@ info:
   version: 0.0.8
 servers:
   - url: http://localhost:3001
+  - url: https://groundcontrol-bluewallet-stg.herokuapp.com
+  - url: https://groundcontrol-bluewallet.herokuapp.com
 paths:
   /lightningInvoiceGotSettled:
     post:
diff --git a/src/class/GroundControlToMajorTom.ts b/src/class/GroundControlToMajorTom.ts
index 6faa786..8907c11 100644
--- a/src/class/GroundControlToMajorTom.ts
+++ b/src/class/GroundControlToMajorTom.ts
@@ -17,11 +17,7 @@ const http2 = require("http2");
  * @see https://firebase.google.com/docs/cloud-messaging/http-server-ref
  */
 export class GroundControlToMajorTom {
-  static async pushOnchainAddressGotUnconfirmedTransaction(
-    serverKey: string,
-    apnsPem: string,
-    pushNotification: Components.Schemas.PushNotificationOnchainAddressGotUnconfirmedTransaction
-  ): Promise<[object, object]> {
+  static async pushOnchainAddressGotUnconfirmedTransaction(serverKey: string, apnsPem: string, pushNotification: Components.Schemas.PushNotificationOnchainAddressGotUnconfirmedTransaction): Promise<[object, object]> {
     const fcmPayload = {
       data: {},
       notification: {
@@ -45,15 +41,10 @@ export class GroundControlToMajorTom {
     };
 
     if (pushNotification.os === "android") return GroundControlToMajorTom._pushToFcm(serverKey, pushNotification.token, fcmPayload, pushNotification);
-    if (pushNotification.os === "ios")
-      return GroundControlToMajorTom._pushToApns(apnsPem, pushNotification.token, apnsPayload, pushNotification, pushNotification.txid);
+    if (pushNotification.os === "ios") return GroundControlToMajorTom._pushToApns(apnsPem, pushNotification.token, apnsPayload, pushNotification, pushNotification.txid);
   }
 
-  static async pushOnchainTxidGotConfirmed(
-    serverKey: string,
-    apnsPem: string,
-    pushNotification: Components.Schemas.PushNotificationTxidGotConfirmed
-  ): Promise<[object, object]> {
+  static async pushOnchainTxidGotConfirmed(serverKey: string, apnsPem: string, pushNotification: Components.Schemas.PushNotificationTxidGotConfirmed): Promise<[object, object]> {
     const fcmPayload = {
       data: {},
       notification: {
@@ -77,15 +68,10 @@ export class GroundControlToMajorTom {
     };
 
     if (pushNotification.os === "android") return GroundControlToMajorTom._pushToFcm(serverKey, pushNotification.token, fcmPayload, pushNotification);
-    if (pushNotification.os === "ios")
-      return GroundControlToMajorTom._pushToApns(apnsPem, pushNotification.token, apnsPayload, pushNotification, pushNotification.txid);
+    if (pushNotification.os === "ios") return GroundControlToMajorTom._pushToApns(apnsPem, pushNotification.token, apnsPayload, pushNotification, pushNotification.txid);
   }
 
-  static async pushOnchainAddressWasPaid(
-    serverKey: string,
-    apnsPem: string,
-    pushNotification: Components.Schemas.PushNotificationOnchainAddressGotPaid
-  ): Promise<[object, object]> {
+  static async pushOnchainAddressWasPaid(serverKey: string, apnsPem: string, pushNotification: Components.Schemas.PushNotificationOnchainAddressGotPaid): Promise<[object, object]> {
     const fcmPayload = {
       data: {},
       notification: {
@@ -109,15 +95,10 @@ export class GroundControlToMajorTom {
     };
 
     if (pushNotification.os === "android") return GroundControlToMajorTom._pushToFcm(serverKey, pushNotification.token, fcmPayload, pushNotification);
-    if (pushNotification.os === "ios")
-      return GroundControlToMajorTom._pushToApns(apnsPem, pushNotification.token, apnsPayload, pushNotification, pushNotification.txid);
+    if (pushNotification.os === "ios") return GroundControlToMajorTom._pushToApns(apnsPem, pushNotification.token, apnsPayload, pushNotification, pushNotification.txid);
   }
 
-  static async pushLightningInvoicePaid(
-    serverKey: string,
-    apnsPem: string,
-    pushNotification: Components.Schemas.PushNotificationLightningInvoicePaid
-  ): Promise<[object, object]> {
+  static async pushLightningInvoicePaid(serverKey: string, apnsPem: string, pushNotification: Components.Schemas.PushNotificationLightningInvoicePaid): Promise<[object, object]> {
     const fcmPayload = {
       data: {},
       notification: {
@@ -141,18 +122,12 @@ export class GroundControlToMajorTom {
     };
 
     if (pushNotification.os === "android") return GroundControlToMajorTom._pushToFcm(serverKey, pushNotification.token, fcmPayload, pushNotification);
-    if (pushNotification.os === "ios")
-      return GroundControlToMajorTom._pushToApns(apnsPem, pushNotification.token, apnsPayload, pushNotification, pushNotification.hash);
+    if (pushNotification.os === "ios") return GroundControlToMajorTom._pushToApns(apnsPem, pushNotification.token, apnsPayload, pushNotification, pushNotification.hash);
   }
 
-  protected static async _pushToApns(
-    apnsPem: string,
-    token: string,
-    apnsPayload: object,
-    pushNotification: Components.Schemas.PushNotificationBase,
-    collapseId
-  ): Promise<[object, object]> {
+  protected static async _pushToApns(apnsPem: string, token: string, apnsPayload: object, pushNotification: Components.Schemas.PushNotificationBase, collapseId): Promise<[object, object]> {
     return new Promise(function (resolve) {
+      // we pass some of the notification properties as data properties to FCM payload:
       for (let dataKey of Object.keys(pushNotification)) {
         if (["token", "os", "badge"].includes(dataKey)) continue;
         apnsPayload["data"][dataKey] = pushNotification[dataKey];
@@ -165,7 +140,7 @@ export class GroundControlToMajorTom {
       client.on("error", (err) => console.error(err));
       const headers = {
         ":method": "POST",
-        "apns-topic": "io.bluewallet.bluewallet",
+        "apns-topic": process.env.APNS_TOPIC,
         "apns-collapse-id": collapseId,
         "apns-expiration": Math.floor(+new Date() / 1000 + 3600 * 24),
         ":scheme": "https",
@@ -206,12 +181,7 @@ export class GroundControlToMajorTom {
     });
   }
 
-  protected static async _pushToFcm(
-    serverKey: string,
-    token: string,
-    fcmPayload: object,
-    pushNotification: Components.Schemas.PushNotificationBase
-  ): Promise<[object, object]> {
+  protected static async _pushToFcm(serverKey: string, token: string, fcmPayload: object, pushNotification: Components.Schemas.PushNotificationBase): Promise<[object, object]> {
     const _api = new Frisbee({ baseURI: "https://fcm.googleapis.com" });
 
     fcmPayload["to"] = token;
diff --git a/src/index.ts b/src/index.ts
index c6c97a3..2f656ea 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -8,6 +8,10 @@ require("dotenv").config();
 const cors = require("cors");
 const url = require("url");
 const parsed = url.parse(process.env.JAWSDB_MARIA_URL);
+if (!process.env.JAWSDB_MARIA_URL || !process.env.FCM_SERVER_KEY || !process.env.APNS_PEM || !process.env.APNS_TOPIC) {
+    console.error("not all env variables set");
+    process.exit();
+}
 
 createConnection({
   type: "mariadb",