diff --git a/.github/workflows/agents-release.yml b/.github/workflows/agents-release.yml
index a4fbe7eb0..90ed5cf2d 100644
--- a/.github/workflows/agents-release.yml
+++ b/.github/workflows/agents-release.yml
@@ -76,9 +76,7 @@ jobs:
       - uses: actions/setup-java@v4
         with:
           distribution: temurin
-          java-version: |
-            8
-            21
+          java-version: "21"
       - uses: gradle/actions/setup-gradle@v4
       - run: ./gradlew shadowJar --parallel
         working-directory: agents
diff --git a/agents/build.gradle b/agents/build.gradle
index 39ef46f48..3699aff09 100644
--- a/agents/build.gradle
+++ b/agents/build.gradle
@@ -2,7 +2,6 @@ plugins {
     id 'com.gradleup.shadow' version '9.0.0-beta12' apply false
 }
 
-def java8Projects = ['common', 'test-support'] as Set
 def infrastructureProjects = ['common', 'test-support'] as Set
 def legacyStandaloneProjects = ['mongodb', 'kafka', 'rocketmq', 'rabbitmq'] as Set
 def agentProjects = subprojects.findAll { !infrastructureProjects.contains(it.name) }
@@ -23,7 +22,7 @@ subprojects {
 
     java {
         toolchain {
-            languageVersion = JavaLanguageVersion.of(java8Projects.contains(name) ? 8 : 21)
+            languageVersion = JavaLanguageVersion.of(21)
         }
     }
 
diff --git a/agents/docs/agent-authoring.md b/agents/docs/agent-authoring.md
index 5aecf95be..b531361d9 100644
--- a/agents/docs/agent-authoring.md
+++ b/agents/docs/agent-authoring.md
@@ -182,18 +182,16 @@ The root `build.gradle` convention derives the archive name from the module name
 Default to:
 
 ```groovy
-def java8Projects = ['common', 'test-support'] as Set
-
 subprojects {
     java {
         toolchain {
-            languageVersion = JavaLanguageVersion.of(java8Projects.contains(name) ? 8 : 21)
+            languageVersion = JavaLanguageVersion.of(21)
         }
     }
 }
 ```
 
-Most agents use JRE 21. If an agent needs a special runtime, update the root Gradle convention, the release workflow JRE detection logic, and document the reason in the module.
+All Java agent modules and shared infrastructure modules use Java 21. If an agent needs a special runtime, update the root Gradle convention, the release workflow JRE detection logic, and document the reason in the module.
 
 ## Tests
 
diff --git a/agents/docs/agent-authoring.zh-CN.md b/agents/docs/agent-authoring.zh-CN.md
index a2f55d97d..a3ba69fd9 100644
--- a/agents/docs/agent-authoring.zh-CN.md
+++ b/agents/docs/agent-authoring.zh-CN.md
@@ -182,18 +182,16 @@ tasks.named('shadowJar') {
 默认配置如下：
 
 ```groovy
-def java8Projects = ['common', 'test-support'] as Set
-
 subprojects {
     java {
         toolchain {
-            languageVersion = JavaLanguageVersion.of(java8Projects.contains(name) ? 8 : 21)
+            languageVersion = JavaLanguageVersion.of(21)
         }
     }
 }
 ```
 
-大多数 Agent 使用 JRE 21。如果某个 Agent 需要特殊的运行时，请更新根 Gradle 约定、发布工作流的 JRE 检测逻辑，并在该模块中记录原因。
+所有 Java Agent 和共享基础设施模块均使用 Java 21。如果某个 Agent 需要特殊的运行时，请更新根 Gradle 约定、发布工作流的 JRE 检测逻辑，并在该模块中记录原因。
 
 ## 测试
 
@@ -315,4 +313,4 @@ class ExampleAgentTest extends JdbcFakeExecutionBehaviorTest {
 - `settings.gradle`、`versions.json`、README 同步更新。
 - 至少有一个执行路径回归测试。
 - `python3 scripts/validate_agents.py` 通过。
-- `./gradlew test shadowJar --continue` 通过。
\ No newline at end of file
+- `./gradlew test shadowJar --continue` 通过。
diff --git a/agents/docs/examples/jdbc-agent-template/build.gradle b/agents/docs/examples/jdbc-agent-template/build.gradle
index 45bec3ac2..3443ed7e2 100644
--- a/agents/docs/examples/jdbc-agent-template/build.gradle
+++ b/agents/docs/examples/jdbc-agent-template/build.gradle
@@ -12,7 +12,7 @@ configure([project(':common'), project(':test-support')]) {
 
     java {
         toolchain {
-            languageVersion = JavaLanguageVersion.of(8)
+            languageVersion = JavaLanguageVersion.of(21)
         }
     }