diff --git a/scripts/start.sh b/scripts/start.sh
index 354f528..07a0df8 100755
--- a/scripts/start.sh
+++ b/scripts/start.sh
@@ -59,10 +59,12 @@ $LUA_COMMAND -e "require('socket')" 2>/dev/null || {
     exit 1
 }
 
-$LUA_COMMAND -e "require('cjson')" 2>/dev/null || {
-    echo -e "${RED}Error: lua-cjson not found${NC}"
+# JSON library check (cjson preferred, dkjson fallback)
+if ! ($LUA_COMMAND -e "require('cjson')" 2>/dev/null || $LUA_COMMAND -e "require('dkjson')" 2>/dev/null); then
+    echo -e "${RED}Error: No JSON library found${NC}"
+    echo "Install lua-cjson or lua-dkjson"
     exit 1
-}
+fi
 
 cd "$PROJECT_DIR"
 
diff --git a/src/main.lua b/src/main.lua
index 8ee7281..5773714 100644
--- a/src/main.lua
+++ b/src/main.lua
@@ -3,7 +3,10 @@
 -- Dragons@Work Digital Sovereignty Project
 
 local socket = require("socket")
-local cjson = require("cjson")
+local found_cjson, cjson = pcall(require, 'cjson')
+if not found_cjson then
+    cjson = require('dkjson')
+end
 
 -- Load modules
 local Auth = require("src.auth")
diff --git a/src/routes/mail.lua b/src/routes/mail.lua
index d7cd93f..8e59b03 100644
--- a/src/routes/mail.lua
+++ b/src/routes/mail.lua
@@ -3,7 +3,10 @@
 -- API-Key determines mail configuration and recipient
 -- Dragons@Work Digital Sovereignty Project
 
-local cjson = require("cjson")
+local found_cjson, cjson = pcall(require, 'cjson')
+if not found_cjson then
+    cjson = require('dkjson')
+end
 
 local MailRoute = {}