diff --git a/.github/workflows/phpunit-feature.yml b/.github/workflows/phpunit-feature.yml
index 177f18693..676bd0319 100644
--- a/.github/workflows/phpunit-feature.yml
+++ b/.github/workflows/phpunit-feature.yml
@@ -5,6 +5,7 @@ on:
     branches:
       - main
   pull_request:
+  merge_group:
   workflow_dispatch:
     inputs:
       corpus_base_ref:
@@ -77,6 +78,9 @@ jobs:
       - name: Require safe PHP image build context
         run: node --test tests/Unit/PhpImageContextTest.mjs
 
+      - name: Run the required checks for merge queue groups
+        run: node --test tests/Unit/MergeGroupTriggersTest.mjs
+
       - name: Validate embedded Workflow package authority
         run: php scripts/ci/test-workflow-package-authority.php
 
@@ -91,7 +95,7 @@ jobs:
 
       - name: Require versioned worker OpenAPI evolution
         env:
-          OPENAPI_BASE_REF: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event_name == 'push' && github.event.before || inputs.corpus_base_ref }}
+          OPENAPI_BASE_REF: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event_name == 'merge_group' && github.event.merge_group.base_sha || github.event_name == 'push' && github.event.before || inputs.corpus_base_ref }}
         run: php scripts/ci/check-worker-openapi-evolution.php "$OPENAPI_BASE_REF"
 
       - name: Audit locked PHP dependencies
@@ -99,7 +103,7 @@ jobs:
 
       - name: Require durable codec evidence
         env:
-          CORPUS_BASE_REF: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event_name == 'push' && github.event.before || inputs.corpus_base_ref }}
+          CORPUS_BASE_REF: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event_name == 'merge_group' && github.event.merge_group.base_sha || github.event_name == 'push' && github.event.before || inputs.corpus_base_ref }}
         run: |
           set -euo pipefail
           if [[ ! "$CORPUS_BASE_REF" =~ ^[0-9a-f]{40}$ ]] || [[ "$CORPUS_BASE_REF" =~ ^0+$ ]]; then
@@ -173,7 +177,7 @@ jobs:
       - name: Run feature, Nexus, and regression corpus suites
         shell: bash
         env:
-          CORPUS_BASE_REF: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event_name == 'push' && github.event.before || inputs.corpus_base_ref }}
+          CORPUS_BASE_REF: ${{ github.event_name == 'pull_request' && github.event.pull_request.base.sha || github.event_name == 'merge_group' && github.event.merge_group.base_sha || github.event_name == 'push' && github.event.before || inputs.corpus_base_ref }}
         run: |
           set -euo pipefail
           if [[ ! "$CORPUS_BASE_REF" =~ ^[0-9a-f]{40}$ ]] || [[ "$CORPUS_BASE_REF" =~ ^0+$ ]]; then
@@ -268,7 +272,7 @@ jobs:
       - name: Select production image qualification for changed build inputs
         id: image_inputs
         run: |
-          if git diff --quiet '${{ github.event.pull_request.base.sha || github.event.before || inputs.corpus_base_ref }}' HEAD -- Dockerfile Dockerfile.dockerignore .dockerignore composer.json composer.lock ':(glob)docker/**'; then
+          if git diff --quiet '${{ github.event.pull_request.base.sha || github.event.merge_group.base_sha || github.event.before || inputs.corpus_base_ref }}' HEAD -- Dockerfile Dockerfile.dockerignore .dockerignore composer.json composer.lock ':(glob)docker/**'; then
             echo 'required=false' >> "$GITHUB_OUTPUT"
           else
             echo 'required=true' >> "$GITHUB_OUTPUT"
diff --git a/.github/workflows/public-boundary.yml b/.github/workflows/public-boundary.yml
index 89bfb4a83..763b55446 100644
--- a/.github/workflows/public-boundary.yml
+++ b/.github/workflows/public-boundary.yml
@@ -2,6 +2,7 @@ name: Public Boundary
 
 on:
   pull_request:
+  merge_group:
   push:
   workflow_dispatch:
 
@@ -28,6 +29,8 @@ jobs:
 
           if [[ "${{ github.event_name }}" == "pull_request" ]]; then
             range="${{ github.event.pull_request.base.sha }}..${{ github.event.pull_request.head.sha }}"
+          elif [[ "${{ github.event_name }}" == "merge_group" ]]; then
+            range="${{ github.event.merge_group.base_sha }}..${{ github.event.merge_group.head_sha }}"
           elif [[ "${{ github.event_name }}" == "workflow_dispatch" ]]; then
             range="-1 ${{ github.sha }}"
           elif [[ "${{ github.event.before }}" =~ ^0+$ ]]; then
diff --git a/.github/workflows/server-parity.yml b/.github/workflows/server-parity.yml
index bdb5bcec3..1416deba5 100644
--- a/.github/workflows/server-parity.yml
+++ b/.github/workflows/server-parity.yml
@@ -114,6 +114,7 @@ on:
       - tests/Support/ServerParityAdmissionObservation.mjs
       - tests/Support/ServerParityVisibilityObservation.mjs
       - rust/**
+  merge_group:
   workflow_dispatch:
 
 # A newer push to the same pull request supersedes the run in progress, so a
diff --git a/tests/Unit/MergeGroupTriggersTest.mjs b/tests/Unit/MergeGroupTriggersTest.mjs
new file mode 100644
index 000000000..e8efba169
--- /dev/null
+++ b/tests/Unit/MergeGroupTriggersTest.mjs
@@ -0,0 +1,49 @@
+// The Actions checks a GitHub merge queue waits for must run on merge_group.
+// Source-only: enabling the queue is a separate repository setting, and its
+// Sonar gate and terminal Shared Server fixtures result are separate
+// prerequisites (Server #725).
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import {readFileSync} from 'node:fs';
+
+const workflow = name => readFileSync(`.github/workflows/${name}`, 'utf8');
+// The top-level `on:` block, up to the next top-level key.
+const triggers = text => {
+  const start = text.indexOf('\non:\n');
+  assert.notEqual(start, -1, 'workflow has an on: block');
+  const rest = text.slice(start + 5);
+  const end = rest.search(/\n[a-z_-]+:/);
+  return end === -1 ? rest : rest.slice(0, end);
+};
+
+for (const name of ['phpunit-feature.yml', 'server-parity.yml', 'public-boundary.yml']) {
+  test(`${name} runs for merge queue groups`, () => {
+    assert.match(triggers(workflow(name)), /^ {2}merge_group:\s*$/m);
+  });
+}
+
+// The Sonar job receives SONAR_TOKEN and its fork guard is always true for a
+// merge group, so candidate source must not reach it through the queue.
+test('SonarQube does not run for merge queue groups', () => {
+  assert.doesNotMatch(triggers(workflow('sonar.yml')), /merge_group/);
+});
+
+test('PHPUnit Feature diffs a queue group against its base', () => {
+  const text = workflow('phpunit-feature.yml');
+  const bases = text.match(/github\.event_name == 'merge_group' && github\.event\.merge_group\.base_sha/g) ?? [];
+  assert.equal(bases.length, 3, 'OpenAPI and both corpus base revisions');
+  assert.match(text, /github\.event\.pull_request\.base\.sha \|\| github\.event\.merge_group\.base_sha \|\| github\.event\.before/);
+});
+
+test('Public Boundary scans a queue group over its exact range and still scans every push', () => {
+  const text = workflow('public-boundary.yml');
+  assert.match(text, /"merge_group" \]\]; then\n\s+range="\$\{\{ github\.event\.merge_group\.base_sha \}\}\.\.\$\{\{ github\.event\.merge_group\.head_sha \}\}"/);
+  assert.match(triggers(text), /^ {2}push:\s*$/m);
+  assert.doesNotMatch(triggers(text), /branches-ignore|branches:|paths/);
+});
+
+test('superseded-run cancellation never cancels a queue group', () => {
+  for (const name of ['phpunit-feature.yml', 'server-parity.yml']) {
+    assert.match(workflow(name), /cancel-in-progress: \$\{\{ github\.event_name == 'pull_request' \}\}/, name);
+  }
+});
diff --git a/tests/Unit/OpenApiDocumentEvolutionTest.php b/tests/Unit/OpenApiDocumentEvolutionTest.php
index 135121125..97499930c 100644
--- a/tests/Unit/OpenApiDocumentEvolutionTest.php
+++ b/tests/Unit/OpenApiDocumentEvolutionTest.php
@@ -55,7 +55,7 @@ public function test_candidate_structure_and_feature_ci_compare_to_the_base_revi
 
         $this->assertCount(1, $preflightStep);
         $this->assertSame(
-            '${{ github.event_name == \'pull_request\' && github.event.pull_request.base.sha || github.event_name == \'push\' && github.event.before || inputs.corpus_base_ref }}',
+            '${{ github.event_name == \'pull_request\' && github.event.pull_request.base.sha || github.event_name == \'merge_group\' && github.event.merge_group.base_sha || github.event_name == \'push\' && github.event.before || inputs.corpus_base_ref }}',
             $preflightStep[0]['env']['OPENAPI_BASE_REF'] ?? null,
         );
         $this->assertSame(
diff --git a/tests/Unit/PhpunitFeatureWorkflowContractTest.php b/tests/Unit/PhpunitFeatureWorkflowContractTest.php
index 14c48570a..b404d7c95 100644
--- a/tests/Unit/PhpunitFeatureWorkflowContractTest.php
+++ b/tests/Unit/PhpunitFeatureWorkflowContractTest.php
@@ -106,7 +106,7 @@ public function test_regression_corpus_validation_uses_git_capable_ci_and_an_exa
         $this->assertSame(0, $checkout['with']['fetch-depth'] ?? null);
         $this->assertFalse($checkout['with']['persist-credentials'] ?? null);
         $this->assertSame(
-            '${{ github.event_name == \'pull_request\' && github.event.pull_request.base.sha || github.event_name == \'push\' && github.event.before || inputs.corpus_base_ref }}',
+            '${{ github.event_name == \'pull_request\' && github.event.pull_request.base.sha || github.event_name == \'merge_group\' && github.event.merge_group.base_sha || github.event_name == \'push\' && github.event.before || inputs.corpus_base_ref }}',
             $execution['env']['CORPUS_BASE_REF'] ?? null,
         );
         $this->assertArrayNotHasKey('if', $execution);