input:
{
  "tierId": 1
}

output:
{
  "subscriptionId": 1,
  "payUrl": "bitcoin:tb1qufxkm89aybhp600aycm54s5ycdj2pqz9hzxj4l?amount=0.40162157",
  "url": "https://api-demo.forgingblock.io/invoice?id=7hqLE4VN5eS5DyhZLzCVby"
}

optional filter: GET /users/me/subscriptions?active=true

output:
[
  {
    "id": 1,
    "tier": "shared",
    "subtier": "free",
    "price": 12.23,
    "dateended": "2019-11-11T12:59:49+00:00",
    "active": true
  }
]

--- a/doc/nautilus.sql
+++ b/doc/nautilus.sql
@@ -26,6 +26,7 @@ create TABLE tiers_configuration(
     dailyhits integer NOT NULL,
     maxresultsetsize integer NOT NULL,
     startdate timestamp NOT NULL,
+    price money NOT NULL,
     FOREIGN KEY (tier, subtier) REFERENCES tiers (tier, subtier)
 );
 create TABLE users(
@@ -56,6 +57,18 @@ create TABLE api_keys(
       REFERENCES users (userid) MATCH SIMPLE
       ON update NO ACTION ON delete NO ACTION
 );
+create TABLE subscriptions(
+    userid integer NOT NULL,
+    tierid serial NOT NULL,
+    price money NOT NULL,
+    dateended timestamp with time zone,
+    CONSTRAINT userid_fk FOREIGN KEY (userid)
+      REFERENCES users (userid) MATCH SIMPLE
+      ON update NO ACTION ON delete NO ACTION
+    CONSTRAINT tierid_fk FOREIGN KEY (tierid)
+      REFERENCES tiers (tierid) MATCH SIMPLE
+      ON update NO ACTION ON delete NO ACTION
+);
 create TABLE usage_left(
     key text NOT NULL,
     daily integer NOT NULL,