diff --git a/teachings.json b/teachings.json
index 3727d97..ba52d47 100644
--- a/teachings.json
+++ b/teachings.json
@@ -900,7 +900,7 @@
   {
     "name": "Computer Vision",
     "url": "computer-vision",
-    "chat": "",
+    "chat": "https://t.me/+9wTytT_D4Lg1MjFk",
     "website": "479049",
     "professors": [
       "giuseppe.lisanti"
@@ -909,7 +909,7 @@
   {
     "name": "Artificial Intelligence, Blockchain e criptovalute nello sviluppo software",
     "url": "artificial-intelligence-blockchain-e-criptovalute-nello-sviluppo-software",
-    "chat": "",
+    "chat": "@AIBC_unibo",
     "website": "495981",
     "professors": [
       "giancarlo.succi"
@@ -918,7 +918,7 @@
   {
     "name": "Cryptography",
     "url": "cryptography",
-    "chat": "",
+    "chat": "https://t.me/+h0CF62a0rNRiNDQ0",
     "website": "479060",
     "professors": [
       "ugo.dallago"
@@ -927,7 +927,7 @@
   {
     "name": "Scalable and Cloud Programming",
     "url": "scalable-and-cloud-programming",
-    "chat": "",
+    "chat": "https://t.me/+-7R_uvQAWGhiODZk",
     "website": "479058",
     "professors": [
       "gianluigi.zavattaro"