diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 2e8dcf7..6f06ce5 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -14,4 +14,5 @@ jobs:
           distribution: temurin
           java-version: '25'
       - uses: gradle/actions/setup-gradle@v6
+      - run: chmod +x gradlew
       - run: ./gradlew clean build
diff --git a/.github/workflows/compatibility.yml b/.github/workflows/compatibility.yml
new file mode 100644
index 0000000..f32d68f
--- /dev/null
+++ b/.github/workflows/compatibility.yml
@@ -0,0 +1,34 @@
+name: Compatibility matrix
+
+on:
+  push:
+  pull_request:
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    name: ${{ matrix.name }}
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - name: Paper 26.2 baseline
+            api: 26.2.build.123-stable
+            java: '25'
+          - name: Paper 26.3
+            api: 26.3.build.157-beta
+            java: '25'
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: ${{ matrix.java }}
+      - uses: gradle/actions/setup-gradle@v4
+      - shell: bash
+        run: chmod +x gradlew
+      - run: ./gradlew clean build --no-daemon -PpaperApiVersion=${{ matrix.api }}
diff --git a/README.md b/README.md
index f511195..46fd8e0 100644
--- a/README.md
+++ b/README.md
@@ -14,3 +14,8 @@ may remain in the configuration for explicit policy and documentation.
 - `/ellanitemmerge status`
 
 Permission: `ellanitemmerge.admin`
+
+## Compatibility
+
+- Paper API compile target: `26.3.build.157-beta`.
+- The plugin descriptor keeps `api-version: 1.21`; live server acceptance remains required.
diff --git a/build.gradle b/build.gradle
index 710e604..0cb0496 100644
--- a/build.gradle
+++ b/build.gradle
@@ -17,7 +17,9 @@ repositories {
 }
 
 dependencies {
-    compileOnly 'io.papermc.paper:paper-api:26.2.build.123-stable'
+    def paperApiVersion = providers.gradleProperty('paperApiVersion').orElse('26.3.build.157-beta').get()
+
+    compileOnly "io.papermc.paper:paper-api:${paperApiVersion}"
 }
 
 tasks.withType(JavaCompile).configureEach {
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index dbc3ce4..a351597 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-9.4.0-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.6.1-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME