diff --git a/a2a/pom.xml b/a2a/pom.xml
index 6afde0404..c5948508e 100644
--- a/a2a/pom.xml
+++ b/a2a/pom.xml
@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
   </parent>
 
   <artifactId>google-adk-a2a</artifactId>
diff --git a/contrib/firestore-session-service/pom.xml b/contrib/firestore-session-service/pom.xml
index ed6922404..d24ab86f8 100644
--- a/contrib/firestore-session-service/pom.xml
+++ b/contrib/firestore-session-service/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../../pom.xml</relativePath>
     </parent>
 
diff --git a/contrib/langchain4j/pom.xml b/contrib/langchain4j/pom.xml
index 2e0e673ee..60f222946 100644
--- a/contrib/langchain4j/pom.xml
+++ b/contrib/langchain4j/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../../pom.xml</relativePath>
     </parent>
 
diff --git a/contrib/planners/pom.xml b/contrib/planners/pom.xml
index 936242833..c9dcf6261 100644
--- a/contrib/planners/pom.xml
+++ b/contrib/planners/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../../pom.xml</relativePath>
     </parent>
 
diff --git a/contrib/samples/a2a_basic/pom.xml b/contrib/samples/a2a_basic/pom.xml
index 4047827b4..fcca8edae 100644
--- a/contrib/samples/a2a_basic/pom.xml
+++ b/contrib/samples/a2a_basic/pom.xml
@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-samples</artifactId>
-    <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/contrib/samples/a2a_server/pom.xml b/contrib/samples/a2a_server/pom.xml
index 8ef73f0c3..53cafffa8 100644
--- a/contrib/samples/a2a_server/pom.xml
+++ b/contrib/samples/a2a_server/pom.xml
@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-samples</artifactId>
-    <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
     <relativePath>..</relativePath>
   </parent>
 
diff --git a/contrib/samples/configagent/pom.xml b/contrib/samples/configagent/pom.xml
index 8118d4c63..91ad73c92 100644
--- a/contrib/samples/configagent/pom.xml
+++ b/contrib/samples/configagent/pom.xml
@@ -5,7 +5,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-samples</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>..</relativePath>
     </parent>
 
diff --git a/contrib/samples/github/adkprtriaging/pom.xml b/contrib/samples/github/adkprtriaging/pom.xml
index 5cfee9df6..7c3856c78 100644
--- a/contrib/samples/github/adkprtriaging/pom.xml
+++ b/contrib/samples/github/adkprtriaging/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-samples</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../..</relativePath>
     </parent>
 
diff --git a/contrib/samples/github/adkreleasedocs/pom.xml b/contrib/samples/github/adkreleasedocs/pom.xml
index c9dd9160c..917a73fb2 100644
--- a/contrib/samples/github/adkreleasedocs/pom.xml
+++ b/contrib/samples/github/adkreleasedocs/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-samples</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../..</relativePath>
     </parent>
 
diff --git a/contrib/samples/github/adkspam/pom.xml b/contrib/samples/github/adkspam/pom.xml
index 390284a9d..ce48840ea 100644
--- a/contrib/samples/github/adkspam/pom.xml
+++ b/contrib/samples/github/adkspam/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-samples</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../..</relativePath>
     </parent>
 
diff --git a/contrib/samples/github/adkstale/pom.xml b/contrib/samples/github/adkstale/pom.xml
index de6eb5cf6..ae886f9bd 100644
--- a/contrib/samples/github/adkstale/pom.xml
+++ b/contrib/samples/github/adkstale/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-samples</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../..</relativePath>
     </parent>
 
diff --git a/contrib/samples/github/adktriaging/pom.xml b/contrib/samples/github/adktriaging/pom.xml
index ba39ce62a..905f00ef6 100644
--- a/contrib/samples/github/adktriaging/pom.xml
+++ b/contrib/samples/github/adktriaging/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-samples</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../..</relativePath>
     </parent>
 
diff --git a/contrib/samples/github/githubtools/pom.xml b/contrib/samples/github/githubtools/pom.xml
index 06b74fab5..8fb81abe4 100644
--- a/contrib/samples/github/githubtools/pom.xml
+++ b/contrib/samples/github/githubtools/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-samples</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../..</relativePath>
     </parent>
 
diff --git a/contrib/samples/helloworld/pom.xml b/contrib/samples/helloworld/pom.xml
index 6fe613f70..dc6f83fcb 100644
--- a/contrib/samples/helloworld/pom.xml
+++ b/contrib/samples/helloworld/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-samples</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>..</relativePath>
     </parent>
 
diff --git a/contrib/samples/mcpfilesystem/pom.xml b/contrib/samples/mcpfilesystem/pom.xml
index a5c46d67e..8a1d3ded4 100644
--- a/contrib/samples/mcpfilesystem/pom.xml
+++ b/contrib/samples/mcpfilesystem/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../../..</relativePath>
     </parent>
 
diff --git a/contrib/samples/pom.xml b/contrib/samples/pom.xml
index 347870068..06f76df04 100644
--- a/contrib/samples/pom.xml
+++ b/contrib/samples/pom.xml
@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
     <relativePath>../..</relativePath>
   </parent>
 
diff --git a/contrib/spring-ai/pom.xml b/contrib/spring-ai/pom.xml
index 27ec2a04d..ca2f0240b 100644
--- a/contrib/spring-ai/pom.xml
+++ b/contrib/spring-ai/pom.xml
@@ -20,7 +20,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../../pom.xml</relativePath>
     </parent>
 
diff --git a/core/pom.xml b/core/pom.xml
index bc6524682..82cdb0a9e 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
   </parent>
 
   <artifactId>google-adk</artifactId>
diff --git a/dev/pom.xml b/dev/pom.xml
index 5dc60f68f..b27c3b995 100644
--- a/dev/pom.xml
+++ b/dev/pom.xml
@@ -18,7 +18,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
   </parent>
 
   <artifactId>google-adk-dev</artifactId>
diff --git a/maven_plugin/examples/custom_tools/pom.xml b/maven_plugin/examples/custom_tools/pom.xml
index da7494f94..9f1ca6ade 100644
--- a/maven_plugin/examples/custom_tools/pom.xml
+++ b/maven_plugin/examples/custom_tools/pom.xml
@@ -4,7 +4,7 @@
 
     <groupId>com.example</groupId>
     <artifactId>custom-tools-example</artifactId>
-    <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
     <packaging>jar</packaging>
 
     <name>ADK Custom Tools Example</name>
diff --git a/maven_plugin/examples/simple-agent/pom.xml b/maven_plugin/examples/simple-agent/pom.xml
index 069b94258..e1bc8fc25 100644
--- a/maven_plugin/examples/simple-agent/pom.xml
+++ b/maven_plugin/examples/simple-agent/pom.xml
@@ -4,7 +4,7 @@
 
     <groupId>com.example</groupId>
     <artifactId>simple-adk-agent</artifactId>
-    <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
     <packaging>jar</packaging>
 
     <name>Simple ADK Agent Example</name>
diff --git a/maven_plugin/pom.xml b/maven_plugin/pom.xml
index c08bbb40a..a89b457d9 100644
--- a/maven_plugin/pom.xml
+++ b/maven_plugin/pom.xml
@@ -5,7 +5,7 @@
     <parent>
         <groupId>com.google.adk</groupId>
         <artifactId>google-adk-parent</artifactId>
-        <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+        <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
         <relativePath>../pom.xml</relativePath>
     </parent>
 
diff --git a/pom.xml b/pom.xml
index bf72a8bb9..9eff18894 100644
--- a/pom.xml
+++ b/pom.xml
@@ -17,7 +17,7 @@
 
   <groupId>com.google.adk</groupId>
   <artifactId>google-adk-parent</artifactId>
-  <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+  <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
   <packaging>pom</packaging>
 
   <name>Google Agent Development Kit Maven Parent POM</name>
diff --git a/tutorials/city-time-weather/pom.xml b/tutorials/city-time-weather/pom.xml
index 86397cf52..3b82d2091 100644
--- a/tutorials/city-time-weather/pom.xml
+++ b/tutorials/city-time-weather/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
     <relativePath>../../pom.xml</relativePath>
   </parent>
 
diff --git a/tutorials/live-audio-single-agent/pom.xml b/tutorials/live-audio-single-agent/pom.xml
index e17e8144b..a75361c57 100644
--- a/tutorials/live-audio-single-agent/pom.xml
+++ b/tutorials/live-audio-single-agent/pom.xml
@@ -20,7 +20,7 @@
   <parent>
     <groupId>com.google.adk</groupId>
     <artifactId>google-adk-parent</artifactId>
-    <version>1.9.0</version><!-- {x-version-update:google-adk:current} -->
+    <version>1.9.1-SNAPSHOT</version><!-- {x-version-update:google-adk:current} -->
     <relativePath>../../pom.xml</relativePath>
   </parent>