diff --git a/VERSION b/VERSION
index 0af471c5..82f85cb4 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.20.0
+5.20.0-dev.1
diff --git a/package.json b/package.json
index 985a41be..bc37a5d8 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@kaitranntt/ccs",
-  "version": "5.20.0",
+  "version": "5.20.0-dev.1",
   "description": "Claude Code Switch - Instant profile switching between Claude Sonnet 4.5 and GLM 4.6",
   "keywords": [
     "cli",