diff --git a/.github/actions/on_device_tests/action.yaml b/.github/actions/on_device_tests/action.yaml
index df6b4bf39d62..17cd7e79c8c3 100644
--- a/.github/actions/on_device_tests/action.yaml
+++ b/.github/actions/on_device_tests/action.yaml
@@ -1,9 +1,97 @@
-name: On Host Tests
-description: Runs on-host tests.
+name: On Device Test
+description: Runs on-device tests.
+inputs:
+  gcs_results_path:
+    description: "GCS path for the test results"
+    required: true
+  results_dir:
+    description: "Path to directory where test results are saved."
+    required: true
+  test_results_key:
+    description: "Artifact key used to store test results."
+    required: true
+
 runs:
   using: "composite"
   steps:
-    - name: Run On-Device Tests
+    - name: Install Requirements
+      # TODO (b/388329764) - set up requirements file.
+      run: |
+        pip3 install grpcio==1.38.0 grpcio-tools==1.38.0
+      shell: bash
+    - name: Generate gRPC files
+      run: |
+        python -m grpc_tools.protoc -I${GITHUB_WORKSPACE}/cobalt/tools/ --python_out=${GITHUB_WORKSPACE}/cobalt/tools/ --grpc_python_out=${GITHUB_WORKSPACE}/cobalt/tools/ ${GITHUB_WORKSPACE}/cobalt/tools/on_device_tests_gateway.proto
+      shell: bash
+    - name: Set Up Cloud SDK
+      uses: isarkis/setup-gcloud@40dce7857b354839efac498d3632050f568090b6 # v1.1.1
+    - name: Set env vars
+      run: |
+        echo "PROJECT_NAME=$(gcloud config get-value project)" >> $GITHUB_ENV
+        # Test results and logs
+        echo "GCS_RESULTS_PATH=gs://cobalt-unittest-storage/results/${{ matrix.name }}/${{ github.run_id }}" >> $GITHUB_ENV
+      shell: bash
+    - name: Run Tests on ${{ matrix.platform }} Platform
+      env:
+        # TODO(b/382508397): Replace hardcoded list with dynamically generated one.
+        TEST_TARGETS_JSON_FILE: cobalt/build/testing/targets/${{ matrix.platform }}/test_targets.json
+        GCS_ARTIFACTS_PATH: /bigstore/${{ env.PROJECT_NAME }}-test-artifacts/${{ github.workflow }}/${{ github.run_number }}/${{ matrix.platform }}
+        GCS_RESULTS_PATH: ${{ inputs.gcs_results_path }}
+        GITHUB_SHA: ${{ github.sha }}
+        GITHUB_TOKEN: ${{ github.token }}
+        GITHUB_EVENT_NAME: ${{ github.event_name }}
+        GITHUB_ACTOR: ${{ github.actor }}
+        GITHUB_TRIGGERING_ACTOR: ${{ github.triggering_actor }}
+        GITHUB_ACTOR_ID: ${{ github.actor_id }}
+        GITHUB_REPO: ${{ github.repository }}
+        GITHUB_PR_HEAD_USER_LOGIN: ${{ github.event.pull_request.head.user.login }}
+        GITHUB_PR_HEAD_USER_ID: ${{ github.event.pull_request.head.user.id }}
+        GITHUB_COMMIT_AUTHOR_USERNAME: ${{ github.event.commits[0].author.username }}
+        GITHUB_COMMIT_AUTHOR_EMAIL: ${{ github.event.commits[0].author.email }}
+        GITHUB_PR_NUMBER: ${{ github.event.pull_request.number }}
+        GITHUB_RUN_NUMBER: ${{ github.run_number }}
+        GITHUB_RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
+        GITHUB_WORKFLOW: ${{ github.workflow }}
+      run: |
+        set -uxe
+        python3 -u cobalt/tools/on_device_tests_gateway_client.py \
+          --token ${GITHUB_TOKEN} \
+          trigger \
+          --targets $(cat "${{ env.TEST_TARGETS_JSON_FILE }}" | jq -cr '.test_targets | join(",")') \
+          --filter_json_dir "${GITHUB_WORKSPACE}/cobalt/testing/filters/${{ matrix.platform}}" \
+          --label github_${GITHUB_PR_NUMBER:-postsubmit} \
+          --label builder-${{ matrix.platform }} \
+          --label builder_url-${GITHUB_RUN_URL} \
+          --label github \
+          --label ${GITHUB_EVENT_NAME} \
+          --label ${GITHUB_WORKFLOW} \
+          --label actor-${GITHUB_ACTOR} \
+          --label actor_id-${GITHUB_ACTOR_ID} \
+          --label triggering_actor-${GITHUB_TRIGGERING_ACTOR} \
+          --label sha-${GITHUB_SHA} \
+          --label repository-${GITHUB_REPO} \
+          --label author-${GITHUB_PR_HEAD_USER_LOGIN:-$GITHUB_COMMIT_AUTHOR_USERNAME} \
+          --label author_id-${GITHUB_PR_HEAD_USER_ID:-$GITHUB_COMMIT_AUTHOR_EMAIL} \
+          ${DIMENSION:+"--dimension" "$DIMENSION"} \
+          ${ON_DEVICE_TEST_ATTEMPTS:+"--test_attempts" "$ON_DEVICE_TEST_ATTEMPTS"} \
+          --gcs_archive_path "${GCS_ARTIFACTS_PATH}" \
+          --gcs_result_path "${GCS_RESULTS_PATH}"
       shell: bash
+    - name: Download ${{ matrix.platform }} Test Results
+      if: always()
+      env:
+        GCS_RESULTS_PATH: ${{ inputs.gcs_results_path }}
+        RESULTS_DIR: ${{ inputs.results_dir }}
       run: |
-        echo "Nothing yet"
+        set -uxe
+        TEST_LOGS="${GITHUB_WORKSPACE}/${RESULTS_DIR}/"
+        mkdir -p "${TEST_LOGS}"
+        gsutil cp -r "${GCS_RESULTS_PATH}/" "${TEST_LOGS}"
+        echo "TEST_LOGS=${TEST_LOGS}" >> $GITHUB_ENV
+      shell: bash
+    - name: Archive Test Results
+      uses: actions/upload-artifact@v3
+      if: always()
+      with:
+        name: ${{ inputs.test_results_key }}
+        path: ${{ env.TEST_LOGS }}/
diff --git a/.github/actions/upload_test_artifacts/action.yaml b/.github/actions/upload_test_artifacts/action.yaml
index a2a645aea29d..c5a6d9cb033c 100644
--- a/.github/actions/upload_test_artifacts/action.yaml
+++ b/.github/actions/upload_test_artifacts/action.yaml
@@ -16,22 +16,7 @@ inputs:
 runs:
   using: "composite"
   steps:
-    - name: Set up Cloud SDK
-      if: inputs.upload_on_device_test_artifacts == 'true'
-      uses: isarkis/setup-gcloud@40dce7857b354839efac498d3632050f568090b6 # v1.1.1
-    - name: Upload Android Test Artifacts to GCS
-      if: inputs.upload_on_device_test_artifacts == 'true'
-      env:
-        WORKFLOW: ${{ github.workflow }}
-      run: |
-        set -eux
-        project_name=$(gcloud config get-value project)
-        gsutil cp "${GITHUB_WORKSPACE}/src/out/${{ matrix.platform }}_${{ matrix.config }}/**/*.apk" \
-          "gs://${project_name}-test-artifacts/${WORKFLOW}/${GITHUB_RUN_NUMBER}/${{matrix.platform}}/"
-      shell: bash
-
-    - name: Create On-Host Test Artifacts Archive
-      if: inputs.upload_on_host_test_artifacts == 'true'
+    - name: Archive Test Artifacts
       run: |
         set -x
         mkdir ${GITHUB_WORKSPACE}/artifacts
@@ -49,3 +34,17 @@ runs:
         name: ${{ inputs.test_artifacts_key }}
         path: artifacts/*
         retention-days: 3
+    - name: Set up Cloud SDK
+      if: inputs.upload_on_device_test_artifacts == 'true'
+      uses: isarkis/setup-gcloud@40dce7857b354839efac498d3632050f568090b6 # v1.1.1
+    - name: Upload Android Test Artifacts to GCS
+      if: inputs.upload_on_device_test_artifacts == 'true'
+      env:
+        WORKFLOW: ${{ github.workflow }}
+      run: |
+        set -eux
+        project_name=$(gcloud config get-value project)
+
+        gsutil cp "${GITHUB_WORKSPACE}/artifacts/*" \
+          "gs://${project_name}-test-artifacts/${WORKFLOW}/${GITHUB_RUN_NUMBER}/${{matrix.platform}}/"
+      shell: bash
diff --git a/.github/config/android-arm.json b/.github/config/android-arm.json
index 99ef53f97c2b..25aec0c3f489 100644
--- a/.github/config/android-arm.json
+++ b/.github/config/android-arm.json
@@ -3,6 +3,11 @@
   "platforms": [
     "android-arm"
   ],
+  "test_on_device": true,
+  "test_dimensions": {
+    "gtest_device": "sabrina",
+    "gtest_lab": "maneki"
+  },
   "targets": [
     "content_shell",
     "system_webview_apk",
diff --git a/.github/config/chromium_android-arm.json b/.github/config/chromium_android-arm.json
index 7e073505527c..50fb7aee1fdb 100644
--- a/.github/config/chromium_android-arm.json
+++ b/.github/config/chromium_android-arm.json
@@ -4,16 +4,6 @@
     "chromium_android-arm"
   ],
   "targets": [
-    "base_unittests",
-    "sql_unittests",
-    "net_unittests",
-    "url_unittests",
-    "ipc_tests",
-    "mojo_unittests",
-    "gpu_unittests",
-    "gin_unittests",
-    "blink_unittests",
-    "media_unittests",
     "content_shell",
     "system_webview_apk",
     "system_webview_shell_apk"
diff --git a/.github/config/chromium_android-arm64.json b/.github/config/chromium_android-arm64.json
index 1921fdbbad91..5c5239614c65 100644
--- a/.github/config/chromium_android-arm64.json
+++ b/.github/config/chromium_android-arm64.json
@@ -4,16 +4,6 @@
     "chromium_android-arm64"
   ],
   "targets": [
-    "base_unittests",
-    "sql_unittests",
-    "net_unittests",
-    "url_unittests",
-    "ipc_tests",
-    "mojo_unittests",
-    "gpu_unittests",
-    "gin_unittests",
-    "blink_unittests",
-    "media_unittests",
     "content_shell",
     "system_webview_apk",
     "system_webview_shell_apk"
diff --git a/.github/config/chromium_android-x86.json b/.github/config/chromium_android-x86.json
index 8498733285ed..ec99f4fcb9db 100644
--- a/.github/config/chromium_android-x86.json
+++ b/.github/config/chromium_android-x86.json
@@ -4,16 +4,6 @@
     "chromium_android-x86"
   ],
   "targets": [
-    "base_unittests",
-    "sql_unittests",
-    "net_unittests",
-    "url_unittests",
-    "ipc_tests",
-    "mojo_unittests",
-    "gpu_unittests",
-    "gin_unittests",
-    "blink_unittests",
-    "media_unittests",
     "content_shell",
     "system_webview_apk",
     "system_webview_shell_apk"
diff --git a/.github/workflows/main.yaml b/.github/workflows/main.yaml
index d521ed65099f..d23f8b1a10c7 100644
--- a/.github/workflows/main.yaml
+++ b/.github/workflows/main.yaml
@@ -145,7 +145,7 @@ jobs:
       matrix:
         platform: ${{ fromJson(needs.initialize.outputs.platforms) }}
         include: ${{ fromJson(needs.initialize.outputs.includes) }}
-        config: [devel, qa, gold]
+        config: [devel]
     container: ${{ needs.docker-build-image.outputs.docker_tag }}
     env:
       TEST_ARTIFACTS_KEY: ${{ matrix.platform }}_${{ matrix.name }}_test_artifacts
@@ -183,9 +183,47 @@ jobs:
           upload_on_host_test_artifacts: ${{ matrix.config == 'devel' && needs.initialize.outputs.test_on_host }}
           upload_on_device_test_artifacts: ${{ matrix.config == 'devel' && needs.initialize.outputs.test_on_device }}
 
-  test:
+  # Runs on-device integration and unit tests.
+  on-device-test:
+    needs: [initialize, build]
+    # Run ODT when on_device label is applied on PR.
+    # Also, run ODT on push and schedule if not explicitly disabled via repo vars.
+    if: needs.initialize.outputs.test_on_device == 'true' &&
+        (
+          (github.event_name == 'pull_request' && contains(github.event.pull_request.labels.*.name, 'on_device')) ||
+          (vars.RUN_ODT_TESTS_ON_NIGHTLY != 'False' && (inputs.nightly == 'true' || github.event_name == 'schedule')) ||
+          (vars.RUN_ODT_TESTS_ON_POSTSUBMIT != 'False' && github.event_name == 'push')
+        )
+    runs-on: [self-hosted, odt-runner]
+    name: ${{ matrix.name }}_on_device
+    permissions: {}
+    strategy:
+      fail-fast: false
+      matrix:
+        platform: ${{ fromJson(needs.initialize.outputs.platforms) }}
+        include: ${{ fromJson(needs.initialize.outputs.includes) }}
+        config: [devel]
+    env:
+      TEST_RESULTS_DIR: ${{ matrix.name }}_test_results
+      TEST_RESULTS_KEY: ${{ matrix.platform }}_${{ matrix.name }}_test_results
+    steps:
+      - name: Checkout
+        uses: kaidokert/checkout@v3.5.999
+        timeout-minutes: 30
+        with:
+          fetch-depth: 1
+          persist-credentials: false
+      - name: Run On-Device Tests (${{ matrix.shard }})
+        id: on-device-tests
+        uses: ./.github/actions/on_device_tests
+        with:
+          test_results_key: ${{ env.TEST_RESULTS_KEY }}
+          gcs_results_path: gs://cobalt-unittest-storage/results/${{ matrix.name }}/${{ github.run_id }}
+          results_dir: ${{ env.TEST_RESULTS_DIR }}
+
+  on-host-test:
     needs: [initialize, docker-build-image, build]
-    if: needs.initialize.outputs.test_on_host == 'true' || needs.initialize.outputs.test_on_device == 'true'
+    if: needs.initialize.outputs.test_on_host == 'true'
     permissions: {}
     # TODO(b/372303096): Should have dedicated runner?
     runs-on: [self-hosted, chrobalt-linux-runner]
@@ -209,7 +247,7 @@ jobs:
           path: src
       - name: Run On-Host Tests
         id: on-host-tests
-        if: always() && needs.initialize.outputs.test_on_host == 'true'
+        if: always()
         uses: ./src/.github/actions/on_host_tests
         with:
           test_artifacts_key: ${{ env.TEST_ARTIFACTS_KEY }}
@@ -217,12 +255,12 @@ jobs:
           num_gtest_shards: ${{ needs.initialize.outputs.num_gtest_shards }}
 
   test-upload:
-    needs: [initialize, docker-build-image, build, test]
+    needs: [initialize, docker-build-image, build, on-host-test, on-device-test]
     if: always() &&
-        (
-          needs.initialize.outputs.test_on_host == 'true' ||
-          needs.initialize.outputs.test_on_device == 'true'
-        )
+      (
+        needs.initialize.outputs.test_on_host == 'true' ||
+        needs.initialize.outputs.test_on_device == 'true'
+      )
     permissions: {}
     runs-on: [self-hosted, chrobalt-linux-runner]
     name: ${{ matrix.name }}_tests_upload
@@ -249,12 +287,12 @@ jobs:
           datadog_api_key: ${{ secrets.datadog_api_key }}
         continue-on-error: true
 
+
   validate-test-result:
-    needs: [initialize, docker-build-image, build, test]
+    needs: [initialize, docker-build-image, build, on-host-test]
     if: always() &&
         (
-          needs.initialize.outputs.test_on_host == 'true' ||
-          needs.initialize.outputs.test_on_device == 'true'
+          needs.initialize.outputs.test_on_host == 'true'
         )
     permissions: {}
     runs-on: ubuntu-latest
diff --git a/cobalt/build/archive_test_artifacts.py b/cobalt/build/archive_test_artifacts.py
index 711f7bb2734c..a2e5e75b625a 100755
--- a/cobalt/build/archive_test_artifacts.py
+++ b/cobalt/build/archive_test_artifacts.py
@@ -17,6 +17,7 @@
 import argparse
 import json
 import os
+import shutil
 import subprocess
 import tempfile
 from typing import List
@@ -35,7 +36,7 @@ def _make_tar(archive_path: str, file_list: str):
 
 
 def create_archive(targets: List[str], source_dir: str, destination_dir: str,
-                   platform: str, combine: bool):
+                   platform: str, uber_archive: bool):
   """Main logic. Collects runtime dependencies from the source directory for
   each target."""
   # TODO(b/382508397): Remove when dynamically generated.
@@ -72,16 +73,27 @@ def create_archive(targets: List[str], source_dir: str, destination_dir: str,
       }
       deps |= target_deps
 
-    if not combine:
+    if not uber_archive:
       output_path = os.path.join(destination_dir, f'{target_name}_deps.tar.gz')
       _make_tar(output_path, deps)
 
-  if combine:
+  if uber_archive:
     output_path = os.path.join(destination_dir, 'test_artifacts.tar.gz')
     _make_tar(output_path, deps)
 
 
-if __name__ == '__main__':
+def copy_apks(targets: List[str], source_dir: str, destination_dir: str):
+  """Copies the target APKs from the source directory to the destination.
+  The path to the APK in the source directory (assumed here to be the out
+  directory) is defined in build/config/android/rules.gni
+  """
+  for target in targets:
+    _, target_name = target.split(':')
+    apk_path = f'{source_dir}/{target_name}_apk/{target_name}-debug.apk'
+    shutil.copy2(apk_path, destination_dir)
+
+
+def main():
   parser = argparse.ArgumentParser()
   parser.add_argument(
       '-s',
@@ -103,9 +115,17 @@ def create_archive(targets: List[str], source_dir: str, destination_dir: str,
       '--targets',
       required=True,
       type=lambda arg: arg.split(','),
-      help='The targets to package, comma-separated. Must be fully qualified '
-      'for android.')
+      help='The targets to package, comma-separated. Must be fully qualified, '
+      'e.g. path/to:target.')
   args = parser.parse_args()
 
+  uber_archive = args.platform.startswith('linux')
   create_archive(args.targets, args.source_dir, args.destination_dir,
-                 args.platform, args.platform.startswith('linux'))
+                 args.platform, uber_archive)
+
+  if args.platform.startswith('android'):
+    copy_apks(args.targets, args.source_dir, args.destination_dir)
+
+
+if __name__ == '__main__':
+  main()
diff --git a/cobalt/testing/filters/android-arm/base_unittests_filter.json b/cobalt/testing/filters/android-arm/base_unittests_filter.json
new file mode 100644
index 000000000000..fb7886542530
--- /dev/null
+++ b/cobalt/testing/filters/android-arm/base_unittests_filter.json
@@ -0,0 +1,6 @@
+{
+  "failing_tests": [
+    "BreakIteratorTest.BreakCharacter",
+    "ValuesUtilTest.FilePath"
+  ]
+}
diff --git a/cobalt/tools/on_device_tests_gateway.proto b/cobalt/tools/on_device_tests_gateway.proto
new file mode 100644
index 000000000000..49f6cdb49917
--- /dev/null
+++ b/cobalt/tools/on_device_tests_gateway.proto
@@ -0,0 +1,69 @@
+// Copyright 2022 The Cobalt Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package on_device_tests_gateway;
+
+// Interface exported by the server.
+service on_device_tests_gateway {
+  // A dumb proxy RPC service that passes user defined command line options
+  // to the on-device tests gateway and streams back output in real time.
+  rpc exec_command(OnDeviceTestsCommand)
+      returns (stream OnDeviceTestsResponse) {}
+
+  // A dumb proxy RPC service that passes user defined command line options
+  // to the on-device tests gateway and streams back output in real time.
+  rpc exec_watch_command(OnDeviceTestsWatchCommand)
+      returns (stream OnDeviceTestsResponse) {}
+}
+
+// Working directory and command line arguments to be passed to the gateway.
+message OnDeviceTestsCommand {
+  string token = 2;
+  repeated string labels = 8;
+  repeated TestRequest test_requests = 24;
+}
+
+message TestRequest {
+  // Args picked up by MH, e.g. "name1=value", "name2=value.
+  repeated string test_args = 1;
+  // Args sent to test binary/apk, e.g. "--arg1", "--arg2=value".
+  repeated string test_cmd_args = 2;
+  // Files to send to device, e.g. "build_apk=/bigstore/bucket/test.apk",
+  // "test_apk=/bigstore/bucket/test.apk",
+  repeated string files = 3;
+  // e.g. "gcs_result_path=gs://some/gcs/path"
+  repeated string params = 4;
+  // "sabrina" or "boreal"
+  string device_type = 5;
+  // "shared" or "maneki"
+  string device_pool = 6;
+}
+
+// Working directory and command line arguments to be passed to the gateway.
+message OnDeviceTestsWatchCommand {
+  // Next ID: 6
+  string workdir = 1;
+  string token = 2;
+  string session_id = 3;
+  string change_id = 4;
+  bool dry_run = 5;
+}
+
+// Response from the on-device tests.
+message OnDeviceTestsResponse {
+  // Next ID: 2
+  string response = 1;
+}
diff --git a/cobalt/tools/on_device_tests_gateway_client.py b/cobalt/tools/on_device_tests_gateway_client.py
new file mode 100644
index 000000000000..a3695a1fc689
--- /dev/null
+++ b/cobalt/tools/on_device_tests_gateway_client.py
@@ -0,0 +1,350 @@
+#!/usr/bin/env python3
+#
+# Copyright 2022 The Cobalt Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""gRPC On-device Tests Gateway client."""
+
+import argparse
+import json
+import logging
+import sys
+from typing import List
+
+import grpc
+import on_device_tests_gateway_pb2
+import on_device_tests_gateway_pb2_grpc
+
+_WORK_DIR = '/on_device_tests_gateway'
+
+# For local testing, set: _ON_DEVICE_TESTS_GATEWAY_SERVICE_HOST = ('localhost')
+_ON_DEVICE_TESTS_GATEWAY_SERVICE_HOST = (
+    'on-device-tests-gateway-service.on-device-tests.svc.cluster.local')
+_ON_DEVICE_TESTS_GATEWAY_SERVICE_PORT = '50052'
+
+# These paths are hardcoded in various places. DO NOT CHANGE!
+_DIR_ON_DEVICE = '/sdcard/Download'
+_DEPS_ARCHIVE = '/sdcard/chromium_tests_root/deps.tar.gz'
+
+
+class OnDeviceTestsGatewayClient():
+  """On-device tests Gateway Client class."""
+
+  def __init__(self):
+    self.channel = grpc.insecure_channel(
+        target=f'{_ON_DEVICE_TESTS_GATEWAY_SERVICE_HOST}:{_ON_DEVICE_TESTS_GATEWAY_SERVICE_PORT}',  # pylint:disable=line-too-long
+        # These options need to match server settings.
+        options=[('grpc.keepalive_time_ms', 10000),
+                 ('grpc.keepalive_timeout_ms', 5000),
+                 ('grpc.keepalive_permit_without_calls', 1),
+                 ('grpc.http2.max_pings_without_data', 0),
+                 ('grpc.http2.min_time_between_pings_ms', 10000),
+                 ('grpc.http2.min_ping_interval_without_data_ms', 5000)])
+    self.stub = on_device_tests_gateway_pb2_grpc.on_device_tests_gatewayStub(
+        self.channel)
+
+  def run_trigger_command(self, token: str, labels: List[str], test_requests):
+    """Calls On-Device Tests service and passing given parameters to it.
+
+    Args:
+        args (Namespace): Arguments passed in command line.
+        test_requests (list): A list of test requests.
+    """
+    for response_line in self.stub.exec_command(
+        on_device_tests_gateway_pb2.OnDeviceTestsCommand(
+            token=token,
+            labels=labels,
+            test_requests=test_requests,
+        )):
+
+      print(response_line.response)
+
+  def run_watch_command(self, token: str, session_id: str):
+    """Calls On-Device Tests watch service and passing given parameters to it.
+
+    Args:
+        args (Namespace): Arguments passed in command line.
+    """
+    for response_line in self.stub.exec_watch_command(
+        on_device_tests_gateway_pb2.OnDeviceTestsWatchCommand(
+            token=token,
+            session_id=session_id,
+        )):
+
+      print(response_line.response)
+
+
+def _read_json_config(filename):
+  """Reads and parses data from a JSON configuration file.
+
+  Args:
+    filename: The name of the JSON configuration file.
+
+  Returns:
+    A list of dictionaries, where each dictionary represents a test
+    configuration.
+  """
+  try:
+    with open(filename, 'r', encoding='utf-8') as f:
+      return json.load(f)
+  except FileNotFoundError:
+    print(f" Config file '{filename}' not found.")
+    raise
+  except json.JSONDecodeError:
+    print(f" Invalid JSON format in '{filename}'.")
+    raise
+
+
+def _get_gtest_filters(filter_json_dir, gtest_target):
+  """Retrieves gtest filters for a given target.
+
+  Args:
+      filter_json_dir: Directory containing filter JSON files.
+      gtest_target: The name of the gtest target.
+
+  Returns:
+      A string containing the gtest filters.
+  """
+  gtest_filters = '*'
+  filter_json_file = f'{filter_json_dir}/{gtest_target}_filter.json'
+  print(f'  gtest_filter_json_file = {filter_json_file}')
+  filter_data = _read_json_config(filter_json_file)
+  if filter_data:
+    print(f'  Loaded filter data: {filter_data}')
+    failing_tests = ':'.join(filter_data.get('failing_tests', []))
+    if failing_tests:
+      gtest_filters += ':-' + failing_tests
+    print(f'  gtest_filters = {gtest_filters}')
+  else:
+    print('  This gtest_target does not have gtest_filters specified')
+  return gtest_filters
+
+
+def _process_test_requests(args):
+  """Processes test requests from the given arguments.
+
+  Constructs a list of test requests based on the provided arguments,
+  including test arguments, command arguments, files, parameters,
+  and device information.
+
+  Args:
+      args: The parsed command-line arguments.
+
+  Returns:
+      A list of test request dictionaries.
+  """
+  test_requests = []
+
+  for gtest_target in args.targets.split(','):
+    print(f'  Processing gtest_target: {gtest_target}')
+
+    tests_args = [
+        f'job_timeout_secs={args.job_timeout_secs}',
+        f'test_timeout_secs={args.test_timeout_secs}',
+        f'start_timeout_secs={args.start_timeout_secs}'
+    ]
+    if args.test_attempts:
+      tests_args.append(f'test_attempts={args.test_attempts}')
+    if args.dimension:
+      tests_args += [f'dimension_{dimension}' for dimension in args.dimension]
+
+    gtest_filter = _get_gtest_filters(args.filter_json_dir, gtest_target)
+    command_line_args = ' '.join([
+        f'--gtest_output=xml:{_DIR_ON_DEVICE}/{gtest_target}_result.xml',
+        f'--gtest_filter={gtest_filter}',
+    ])
+    test_cmd_args = [f'command_line_args={command_line_args}']
+
+    files = [
+        f'test_apk={args.gcs_archive_path}/{gtest_target}-debug.apk',
+        f'build_apk={args.gcs_archive_path}/{gtest_target}-debug.apk',
+        f'test_runtime_deps={args.gcs_archive_path}/{gtest_target}_deps.tar.gz',
+    ]
+
+    params = []
+    if args.gcs_result_path:
+      params.append(f'gcs_result_path={args.gcs_result_path}')
+    params += [
+        f'push_files=test_runtime_deps:{_DEPS_ARCHIVE}',
+        f'gtest_xml_file_on_device={_DIR_ON_DEVICE}/{gtest_target}_result.xml',
+        f'gcs_result_filename={gtest_target}_result.xml',
+        f'gcs_log_filename={gtest_target}_log.txt'
+    ]
+
+    # TODO(oxv): Figure out how to get dimensions from config to here.
+    device_type = 'sabrina'
+    device_pool = 'maneki'
+
+    test_requests.append({
+        'test_args': tests_args,
+        'test_cmd_args': test_cmd_args,
+        'files': files,
+        'params': params,
+        'device_type': device_type,
+        'device_pool': device_pool,
+    })
+  return test_requests
+
+
+def main() -> int:
+  """Main routine for the on-device tests gateway client."""
+
+  logging.basicConfig(
+      level=logging.INFO, format='[%(filename)s:%(lineno)s] %(message)s')
+  print('Starting main routine')
+
+  parser = argparse.ArgumentParser(
+      description='Client for interacting with the On-Device Tests gateway.',
+      epilog=('Example:'
+              'python3 -u cobalt/tools/on_device_tests_gateway_client.py'
+              '--platform_json "${GITHUB_WORKSPACE}/src/.github/config/'
+              '${{ matrix.platform}}.json"'
+              '--filter_json_dir "${GITHUB_WORKSPACE}/src/cobalt/testing/'
+              '${{ matrix.platform}}"'
+              '--token ${GITHUB_TOKEN}'
+              '--label builder-${{ matrix.platform }}'
+              '--label builder_url-${GITHUB_RUN_URL}'
+              '--label github'
+              '--label ${GITHUB_EVENT_NAME}'
+              '--label ${GITHUB_WORKFLOW}'
+              '--label actor-${GITHUB_ACTOR}'
+              '--label actor_id-${GITHUB_ACTOR_ID}'
+              '--label triggering_actor-${GITHUB_TRIGGERING_ACTOR}'
+              '--label sha-${GITHUB_SHA}'
+              '--label repository-${GITHUB_REPO}'
+              '--label author-${GITHUB_PR_HEAD_USER_LOGIN:-'
+              '$GITHUB_COMMIT_AUTHOR_USERNAME}'
+              '--label author_id-${GITHUB_PR_HEAD_USER_ID:-'
+              '$GITHUB_COMMIT_AUTHOR_EMAIL}'
+              '--dimension host_name=regex:maneki-mhserver-05.*'
+              '${DIMENSION:+"--dimension" "$DIMENSION"}'
+              '${ON_DEVICE_TEST_ATTEMPTS:+"--test_attempts" '
+              '"$ON_DEVICE_TEST_ATTEMPTS"}'
+              '--gcs_archive_path "${GCS_ARTIFACTS_PATH}"'
+              '--gcs_result_path "${GCS_RESULTS_PATH}"'
+              'trigger'),
+      formatter_class=argparse.RawDescriptionHelpFormatter,
+  )
+
+  # Authentication
+  parser.add_argument(
+      '-t',
+      '--token',
+      type=str,
+      required=True,
+      help='On Device Tests authentication token',
+  )
+  subparsers = parser.add_subparsers(
+      dest='action', help='On-Device tests commands', required=True)
+
+  # Trigger command
+  trigger_parser = subparsers.add_parser(
+      'trigger',
+      help='Trigger On-Device tests',
+      formatter_class=argparse.ArgumentDefaultsHelpFormatter,
+  )
+
+  # Group trigger arguments
+  trigger_args = trigger_parser.add_argument_group('Trigger Arguments')
+  trigger_parser.add_argument(
+      '--targets',
+      type=str,
+      required=True,
+      help='List of targets to test, comma separated. Must be fully qualified '
+      'ninja target.',
+  )
+  trigger_parser.add_argument(
+      '--filter_json_dir',
+      type=str,
+      required=True,
+      help='Directory containing filter JSON files for test selection.',
+  )
+  trigger_parser.add_argument(
+      '-l',
+      '--label',
+      type=str,
+      action='append',
+      help='Additional labels to assign to the test.',
+  )
+  trigger_parser.add_argument(
+      '--dimension',
+      type=str,
+      action='append',
+      help='On-Device Tests dimension used to select a device. Must have the '
+      'following form: <dimension>=<value>. E.G. "release_version=regex:10.*"',
+  )
+  trigger_parser.add_argument(
+      '--test_attempts',
+      type=str,
+      default='1',
+      help='The maximum number of times a test can retry.',
+  )
+  trigger_args.add_argument(
+      '-a',
+      '--gcs_archive_path',
+      type=str,
+      required=True,
+      help='Path to Chrobalt archive to be tested. Must be on GCS.',
+  )
+  trigger_parser.add_argument(
+      '--gcs_result_path',
+      type=str,
+      help='GCS URL where test result files should be uploaded.',
+  )
+  trigger_parser.add_argument(
+      '--job_timeout_secs',
+      type=str,
+      default='1800',
+      help='Timeout in seconds for the job (default: 1800 seconds).',
+  )
+  trigger_parser.add_argument(
+      '--test_timeout_secs',
+      type=str,
+      default='1800',
+      help='Timeout in seconds for the test (default: 1800 seconds).',
+  )
+  trigger_parser.add_argument(
+      '--start_timeout_secs',
+      type=str,
+      default='180',
+      help='Timeout in seconds for the test to start (default: 180 seconds).',
+  )
+
+  # Watch command
+  watch_parser = subparsers.add_parser(
+      'watch', help='Watch a previously triggered On-Device test')
+  watch_parser.add_argument(
+      'session_id',
+      type=str,
+      help=('Session ID of a previously triggered Mobile Harness test. '
+            'The test will be watched until it completes.'),
+  )
+
+  args = parser.parse_args()
+  test_requests = _process_test_requests(args)
+
+  client = OnDeviceTestsGatewayClient()
+  try:
+    if args.action == 'trigger':
+      client.run_trigger_command(args.token, args.label, test_requests)
+    else:
+      client.run_watch_command(args.token, args.session_id)
+  except grpc.RpcError as e:
+    logging.exception('gRPC error occurred:')  # Log the full traceback
+    return e.code().value  # Return the error code
+
+  return 0  # Indicate successful execution
+
+
+if __name__ == '__main__':
+  sys.exit(main())