diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 8495648..5bd0f17 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -3,34 +3,51 @@ name: build
 on:
   pull_request:
     branches: [ "main" ]
-  merge_group:
-    types: [ checks_requested ]
+  push:
+    branches: [ "main" ]
 
-jobs:
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
 
+jobs:
   changed-files:
     name: changed-files
     runs-on: ubuntu-latest
     outputs:
-      src: ${{ steps.changed-files-yaml.outputs.src_any_changed }}
-      lightweight: ${{ steps.changed-files-yaml.outputs.lightweight_any_changed }}
-      miri: ${{ steps.changed-files-yaml.outputs.miri_any_changed }}
+      simulator: ${{ steps.changed-files-yaml.outputs.simulator_any_changed }}
+      soem: ${{ steps.changed-files-yaml.outputs.soem_any_changed }}
+      twincat: ${{ steps.changed-files-yaml.outputs.twincat_any_changed }}
+      main: ${{ steps.changed-files-yaml.outputs.main_any_changed }}
     steps:
       - uses: actions/checkout@v4
       - id: changed-files-yaml
         uses: tj-actions/changed-files@v44
         with:
           files_yaml: |
-            src:
-              - '**/*.rs'
-              - '**/Cargo.toml'
+            simulator:
+              - 'simulator/**/*.rs'
+              - 'simulator/Cargo.toml'
+            soem:
+              - 'SOEMAUTDServer/**/*.rs'
+              - 'SOEMAUTDServer/Cargo.toml'
+            twincat:
+              - 'TwinCATAUTDServerLightweight/**/*.rs'
+              - 'TwinCATAUTDServerLightweight/Cargo.toml'
+            main:
+              - 'src-tauri/**/*.rs'
+              - 'src-tauri/Cargo.toml'
+              - 'src/**/*.svelte'
               - '**/*.ts'
-              - '**/*.svelte'
+              - '**/*.js'
+              - '**/*.html'
               - 'package.json'
+              - 'tsconfig.json'
+              - 'tsconfig.node.json'
 
-  test:
+  test-simulator:
     needs: changed-files
-    name: test-on-${{ matrix.os }}
+    name: test-simulator-on-${{ matrix.os }}
     runs-on: ${{ matrix.os }}
     strategy:
       fail-fast: false
@@ -38,18 +55,95 @@ jobs:
         os: [macos-latest, ubuntu-latest, windows-latest]
     steps:
       - uses: actions/checkout@v4
-        if: ${{ needs.changed-files.outputs.src == 'true' }}
+        if: ${{ needs.changed-files.outputs.simulator == 'true' }}
       - uses: ./.github/actions/setup-build
         with:
           os: ${{ matrix.os }}
-        if: ${{ needs.changed-files.outputs.src == 'true' }}
+        if: ${{ needs.changed-files.outputs.simulator == 'true' }}
+      - run: |
+          python3 build.py build --simulator
+          python3 build.py lint --simulator
+        if: ${{ needs.changed-files.outputs.simulator == 'true' }}
+
+  test-soem:
+    needs: changed-files
+    name: test-soem-on-${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos-latest, ubuntu-latest, windows-latest]
+    steps:
+      - uses: actions/checkout@v4
+        if: ${{ needs.changed-files.outputs.soem == 'true' }}
+      - uses: ./.github/actions/setup-build
+        with:
+          os: ${{ matrix.os }}
+        if: ${{ needs.changed-files.outputs.soem == 'true' }}
+      - run: |
+          python3 build.py build --soem
+          python3 build.py lint --soem
+        if: ${{ needs.changed-files.outputs.soem == 'true' }}
+
+  test-twincat:
+    needs: changed-files
+    name: test-twincat-on-${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos-latest, ubuntu-latest, windows-latest]
+    steps:
+      - uses: actions/checkout@v4
+        if: ${{ needs.changed-files.outputs.twincat == 'true' }}
+      - uses: ./.github/actions/setup-build
+        with:
+          os: ${{ matrix.os }}
+        if: ${{ needs.changed-files.outputs.twincat == 'true' }}
+      - run: |
+          python3 build.py build --twincat
+          python3 build.py lint --twincat
+        if: ${{ needs.changed-files.outputs.twincat == 'true' }}
+
+  test-main:
+    needs: changed-files
+    name: test-main-on-${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos-latest, ubuntu-latest, windows-latest]
+    steps:
+      - uses: actions/checkout@v4
+        if: ${{ needs.changed-files.outputs.main == 'true' }}
+      - uses: ./.github/actions/setup-build
+        with:
+          os: ${{ matrix.os }}
+        if: ${{ needs.changed-files.outputs.main == 'true' }}
       - uses: actions/setup-node@v4
         with:
           node-version: 'lts/*'
           cache: 'npm'
           cache-dependency-path: package-lock.json
-        if: ${{ needs.changed-files.outputs.src == 'true' }}
+        if: ${{ needs.changed-files.outputs.main == 'true' }}
       - run: |
-          python3 build.py build
-          python3 build.py lint
-        if: ${{ needs.changed-files.outputs.src == 'true' }}
+          python3 build.py build --main
+          python3 build.py lint --main
+        if: ${{ needs.changed-files.outputs.main == 'true' }}
+
+  auto-merge:
+    needs:
+      - test-simulator
+      - test-soem
+      - test-twincat
+      - test-main
+    permissions:
+      pull-requests: write
+      contents: write
+    runs-on: ubuntu-latest
+    if: ${{ always() && !cancelled() && !failure() && github.actor == 'dependabot[bot]' }}
+    steps:
+      - run: gh pr merge --rebase --auto "$PR_URL"
+        env:
+          PR_URL: ${{github.event.pull_request.html_url}}
+          GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
diff --git a/build.py b/build.py
index eebf4c6..2301f97 100644
--- a/build.py
+++ b/build.py
@@ -135,50 +135,93 @@ def server_build(args):
 
     shell = True if config.is_windows() else False
 
-    with working_dir("simulator"):
-        subprocess.run(
-            [
-                "cargo",
-                "build",
-                "--release",
-                "--features",
-                "unity",
-            ]
-        ).check_returncode()
-    if config.is_windows():
-        shutil.copy(
-            "target/release/simulator.exe",
-            "target/release/simulator-unity.exe",
-        )
-    else:
-        shutil.copy(
-            "target/release/simulator",
-            "target/release/simulator-unity",
-        )
+    if args.simulator:
+        with working_dir("simulator"):
+            subprocess.run(
+                [
+                    "cargo",
+                    "build",
+                    "--release",
+                    "--features",
+                    "unity",
+                ]
+            ).check_returncode()
+        if config.is_windows():
+            shutil.copy(
+                "target/release/simulator.exe",
+                "target/release/simulator-unity.exe",
+            )
+        else:
+            shutil.copy(
+                "target/release/simulator",
+                "target/release/simulator-unity",
+            )
+
+        with working_dir("simulator"):
+            subprocess.run(["cargo", "build", "--release"]).check_returncode()
+
+    if args.soem:
+        with working_dir("SOEMAUTDServer"):
+            subprocess.run(["cargo", "build", "--release"]).check_returncode()
+
+    if args.twincat:
+        with working_dir("TwinCATAUTDServerLightweight"):
+            subprocess.run(["cargo", "build", "--release"]).check_returncode()
 
-    with working_dir("simulator"):
-        subprocess.run(["cargo", "build", "--release"]).check_returncode()
+    if args.main:
+        subprocess.run(["npm", "install"], shell=shell).check_returncode()
 
-    with working_dir("SOEMAUTDServer"):
-        subprocess.run(["cargo", "build", "--release"]).check_returncode()
+        def create_dummy_if_not_exists(file):
+            if config.is_windows():
+                file += ".exe"
+            if not os.path.exists(file):
+                with open(file, "w") as f:
+                    f.write("")
 
-    with working_dir("TwinCATAUTDServerLightweight"):
-        subprocess.run(["cargo", "build", "--release"]).check_returncode()
+        create_dummy_if_not_exists("target/release/simulator-unity")
+        create_dummy_if_not_exists("target/release/simulator")
+        create_dummy_if_not_exists("target/release/SOEMAUTDServer")
+        create_dummy_if_not_exists("target/release/TwinCATAUTDServerLightweight")
 
-    subprocess.run(["npm", "install"], shell=shell).check_returncode()
-    if not args.external_only:
         subprocess.run(["npm", "run", "tauri", "build"], shell=shell).check_returncode()
 
 
 def server_lint(args):
-    with working_dir("."):
-        command = ["cargo", "clippy"]
-        command.append("--tests")
-        command.append("--workspace")
-        command.append("--")
-        command.append("-D")
-        command.append("warnings")
-        subprocess.run(command).check_returncode()
+    if args.simulator:
+        with working_dir("simulator"):
+            command = ["cargo", "clippy"]
+            command.append("--tests")
+            command.append("--")
+            command.append("-D")
+            command.append("warnings")
+            subprocess.run(command).check_returncode()
+
+    if args.soem:
+        with working_dir("SOEMAUTDServer"):
+            command = ["cargo", "clippy"]
+            command.append("--tests")
+            command.append("--")
+            command.append("-D")
+            command.append("warnings")
+            subprocess.run(command).check_returncode()
+
+    if args.twincat:
+        with working_dir("TwinCATAUTDServerLightweight"):
+            command = ["cargo", "clippy"]
+            command.append("--tests")
+            command.append("--")
+            command.append("-D")
+            command.append("warnings")
+            subprocess.run(command).check_returncode()
+
+    if args.main:
+        with working_dir("src-tauri"):
+            command = ["cargo", "clippy"]
+            command.append("--tests")
+            command.append("--")
+            command.append("-D")
+            command.append("warnings")
+            subprocess.run(command).check_returncode()
 
 
 def server_clear(args):
@@ -321,14 +364,33 @@ def command_help(args):
         # build
         parser_server_build = subparsers.add_parser("build", help="see `build -h`")
         parser_server_build.add_argument(
-            "--external-only",
-            action="store_true",
-            help="build external dependencies only",
+            "--simulator", action="store_true", help="build simulator"
+        )
+        parser_server_build.add_argument(
+            "--soem", action="store_true", help="build SOEM Server"
+        )
+        parser_server_build.add_argument(
+            "--twincat", action="store_true", help="build TwinCAT Server"
+        )
+        parser_server_build.add_argument(
+            "--main", action="store_true", help="build main app"
         )
         parser_server_build.set_defaults(handler=server_build)
 
         # lint
         parser_server_lint = subparsers.add_parser("lint", help="see `lint -h`")
+        parser_server_lint.add_argument(
+            "--simulator", action="store_true", help="build simulator"
+        )
+        parser_server_lint.add_argument(
+            "--soem", action="store_true", help="build SOEM Server"
+        )
+        parser_server_lint.add_argument(
+            "--twincat", action="store_true", help="build TwinCAT Server"
+        )
+        parser_server_lint.add_argument(
+            "--main", action="store_true", help="build main app"
+        )
         parser_server_lint.set_defaults(handler=server_lint)
 
         # server clear