diff --git a/.github/actions/diff-js-api-changes/action.yml b/.github/actions/diff-js-api-changes/action.yml
index 9e186d27cc01..b1055e2ed379 100644
--- a/.github/actions/diff-js-api-changes/action.yml
+++ b/.github/actions/diff-js-api-changes/action.yml
@@ -1,24 +1,31 @@
 name: diff-js-api-changes
 description: Check for breaking changes in the public React Native JS API
+outputs:
+  message:
+    description: "Formatted message for PR comment, empty if no API changes"
+    value: ${{ steps.format.outputs.message }}
 runs:
   using: composite
   steps:
-    - name: Compute merge base with main
+    - name: Fetch PR and main, compute merge base
       id: merge_base
       shell: bash
       run: |
         git fetch origin main
-        git fetch --deepen=500
-        echo "merge_base=$(git merge-base HEAD origin/main)" >> $GITHUB_OUTPUT
+        git fetch origin ${{ github.event.pull_request.head.sha }} --depth=500
+        echo "merge_base=$(git merge-base ${{ github.event.pull_request.head.sha }} origin/main)" >> $GITHUB_OUTPUT
 
-    - name: Output snapshot before state for comparison
+    - name: Extract before and after API snapshots
       shell: bash
       env:
         SCRATCH_DIR: ${{ runner.temp }}/diff-js-api-changes
       run: |
+        rm -rf $SCRATCH_DIR
         mkdir -p $SCRATCH_DIR
         git show ${{ steps.merge_base.outputs.merge_base }}:packages/react-native/ReactNativeApi.d.ts > $SCRATCH_DIR/ReactNativeApi-before.d.ts \
           || echo "" > $SCRATCH_DIR/ReactNativeApi-before.d.ts
+        git show ${{ github.event.pull_request.head.sha }}:packages/react-native/ReactNativeApi.d.ts > $SCRATCH_DIR/ReactNativeApi-after.d.ts \
+          || echo "" > $SCRATCH_DIR/ReactNativeApi-after.d.ts
 
     - name: Run breaking change detection
       shell: bash
@@ -27,5 +34,37 @@ runs:
       run: |
         node ./scripts/js-api/diff-api-snapshot \
           $SCRATCH_DIR/ReactNativeApi-before.d.ts \
-          ./packages/react-native/ReactNativeApi.d.ts \
+          $SCRATCH_DIR/ReactNativeApi-after.d.ts \
           > $SCRATCH_DIR/output.json
+
+    - name: Format output message
+      id: format
+      shell: bash
+      env:
+        SCRATCH_DIR: ${{ runner.temp }}/diff-js-api-changes
+      run: |
+        if [ ! -f "$SCRATCH_DIR/output.json" ]; then
+          echo "message=" >> $GITHUB_OUTPUT
+          exit 0
+        fi
+
+        RESULT=$(cat $SCRATCH_DIR/output.json | jq -r '.result // empty')
+        if [ -z "$RESULT" ]; then
+          echo "message=" >> $GITHUB_OUTPUT
+          exit 0
+        fi
+
+        # Use delimiter for multiline output
+        {
+          echo "message<<EOF"
+          echo "> [!WARNING]"
+          echo "> **JavaScript API change detected**"
+          echo ">"
+          echo "> This PR commits an update to \`ReactNativeApi.d.ts\`, indicating a change to React Native's public JavaScript API."
+          echo ">"
+          echo "> - Please include a **clear changelog message**."
+          echo "> - This change will be subject to additional review."
+          echo ">"
+          echo "> This change was flagged as: \`${RESULT}\`"
+          echo "EOF"
+        } >> $GITHUB_OUTPUT
diff --git a/.github/workflow-scripts/__tests__/postPRComment-test.js b/.github/workflow-scripts/__tests__/postPRComment-test.js
new file mode 100644
index 000000000000..a62bf478f1fb
--- /dev/null
+++ b/.github/workflow-scripts/__tests__/postPRComment-test.js
@@ -0,0 +1,128 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+const postPRComment = require('../postPRComment');
+const {_COMMENT_MARKER} = postPRComment;
+
+describe('postPRComment', () => {
+  beforeEach(() => {
+    jest.clearAllMocks();
+    jest.spyOn(console, 'log').mockImplementation(() => {});
+  });
+
+  const mockGithub = {
+    rest: {
+      issues: {
+        listComments: jest.fn(),
+        createComment: jest.fn(),
+        updateComment: jest.fn(),
+        deleteComment: jest.fn(),
+      },
+    },
+  };
+
+  const mockContext = {
+    repo: {owner: 'facebook', repo: 'react-native'},
+    payload: {pull_request: {number: 123}},
+  };
+
+  beforeEach(() => {
+    mockGithub.rest.issues.listComments.mockResolvedValue({data: []});
+    mockGithub.rest.issues.createComment.mockResolvedValue({});
+    mockGithub.rest.issues.updateComment.mockResolvedValue({});
+    mockGithub.rest.issues.deleteComment.mockResolvedValue({});
+  });
+
+  it('does nothing when no messages and no existing comment', async () => {
+    await postPRComment(mockGithub, mockContext, {messages: []});
+
+    expect(mockGithub.rest.issues.createComment).not.toHaveBeenCalled();
+    expect(mockGithub.rest.issues.deleteComment).not.toHaveBeenCalled();
+  });
+
+  it('filters out empty and null messages', async () => {
+    await postPRComment(mockGithub, mockContext, {
+      messages: ['', null, '   ', undefined],
+    });
+
+    expect(mockGithub.rest.issues.createComment).not.toHaveBeenCalled();
+  });
+
+  it('deletes existing comment when no messages to report', async () => {
+    const existingComment = {
+      id: 456,
+      body: `${_COMMENT_MARKER}\nOld content`,
+    };
+    mockGithub.rest.issues.listComments.mockResolvedValue({
+      data: [existingComment],
+    });
+
+    await postPRComment(mockGithub, mockContext, {messages: []});
+
+    expect(mockGithub.rest.issues.deleteComment).toHaveBeenCalledWith({
+      owner: 'facebook',
+      repo: 'react-native',
+      comment_id: 456,
+    });
+  });
+
+  it('creates new comment when there are messages', async () => {
+    await postPRComment(mockGithub, mockContext, {
+      messages: ['### Test Message\n\nSome content'],
+    });
+
+    expect(mockGithub.rest.issues.createComment).toHaveBeenCalledWith({
+      owner: 'facebook',
+      repo: 'react-native',
+      issue_number: 123,
+      body: expect.stringContaining(_COMMENT_MARKER),
+    });
+    expect(mockGithub.rest.issues.createComment).toHaveBeenCalledWith({
+      owner: 'facebook',
+      repo: 'react-native',
+      issue_number: 123,
+      body: expect.stringContaining('Test Message'),
+    });
+  });
+
+  it('updates existing comment when there are messages', async () => {
+    const existingComment = {
+      id: 789,
+      body: `${_COMMENT_MARKER}\nOld content`,
+    };
+    mockGithub.rest.issues.listComments.mockResolvedValue({
+      data: [existingComment],
+    });
+
+    await postPRComment(mockGithub, mockContext, {
+      messages: ['### Updated Message'],
+    });
+
+    expect(mockGithub.rest.issues.updateComment).toHaveBeenCalledWith({
+      owner: 'facebook',
+      repo: 'react-native',
+      comment_id: 789,
+      body: expect.stringContaining(_COMMENT_MARKER),
+    });
+    expect(mockGithub.rest.issues.createComment).not.toHaveBeenCalled();
+  });
+
+  it('combines multiple messages with double newlines', async () => {
+    await postPRComment(mockGithub, mockContext, {
+      messages: ['Message 1', 'Message 2'],
+    });
+
+    expect(mockGithub.rest.issues.createComment).toHaveBeenCalledWith({
+      owner: 'facebook',
+      repo: 'react-native',
+      issue_number: 123,
+      body: expect.stringContaining('Message 1\n\nMessage 2'),
+    });
+  });
+});
diff --git a/.github/workflow-scripts/postPRComment.js b/.github/workflow-scripts/postPRComment.js
new file mode 100644
index 000000000000..ec49f6bead72
--- /dev/null
+++ b/.github/workflow-scripts/postPRComment.js
@@ -0,0 +1,77 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @format
+ */
+
+const COMMENT_MARKER = '<!-- react-native-bot -->';
+
+/**
+ * Posts a PR validation comment, updates an existing one, or deletes it if there's nothing to report.
+ *
+ * @param {Object} github - The octokit client from actions/github-script
+ * @param {Object} context - The GitHub Actions context
+ * @param {Object} options - Options for the comment
+ * @param {string[]} [options.messages] - Array of message strings to include in the comment
+ */
+async function postPRComment(github, context, options) {
+  const {owner, repo} = context.repo;
+  const prNumber = context.payload.pull_request.number;
+
+  const sections = (options.messages || []).filter(
+    msg => msg != null && msg.trim() !== '',
+  );
+
+  const {data: comments} = await github.rest.issues.listComments({
+    owner,
+    repo,
+    issue_number: prNumber,
+  });
+
+  const existingComment = comments.find(comment =>
+    comment.body.includes(COMMENT_MARKER),
+  );
+
+  if (sections.length === 0) {
+    console.log('No issues to report');
+    if (existingComment) {
+      console.log(`Deleting existing comment ${existingComment.id}`);
+      await github.rest.issues.deleteComment({
+        owner,
+        repo,
+        comment_id: existingComment.id,
+      });
+    }
+    return;
+  }
+
+  const commentBody = `${COMMENT_MARKER}
+## PR Validation
+
+${sections.join('\n\n')}`;
+
+  if (existingComment) {
+    console.log(`Updating existing comment ${existingComment.id}`);
+    await github.rest.issues.updateComment({
+      owner,
+      repo,
+      comment_id: existingComment.id,
+      body: commentBody,
+    });
+  } else {
+    console.log('Creating new comment');
+    await github.rest.issues.createComment({
+      owner,
+      repo,
+      issue_number: prNumber,
+      body: commentBody,
+    });
+  }
+}
+
+module.exports = postPRComment;
+// Exported for testing purposes
+module.exports._COMMENT_MARKER = COMMENT_MARKER;
diff --git a/.github/workflows/annotate-pr.yml b/.github/workflows/annotate-pr.yml
new file mode 100644
index 000000000000..d1743c897182
--- /dev/null
+++ b/.github/workflows/annotate-pr.yml
@@ -0,0 +1,41 @@
+name: Annotate PR
+
+on:
+  pull_request_target:
+    types: [opened, edited, reopened, synchronize]
+
+permissions:
+  pull-requests: write
+
+jobs:
+  annotate-pr:
+    runs-on: ubuntu-latest
+    # if: github.repository == 'facebook/react-native' temp
+    steps:
+      - name: Check out main branch
+        uses: actions/checkout@v6
+      - name: Setup Node.js
+        uses: ./.github/actions/setup-node
+      - name: Run yarn install
+        uses: ./.github/actions/yarn-install
+      - name: Run diff-js-api-changes
+        id: diff-js-api
+        uses: ./.github/actions/diff-js-api-changes
+      # - name: Check PR body
+        # todo
+        # uses: ./.github/actions/check-pr-body
+      # - name: Branch Targetting
+        # todo
+        # uses: ./.github/actions/check-branch-target
+      - name: Post PR comment
+        uses: actions/github-script@v8
+        env:
+          API_CHANGES_MESSAGE: ${{ steps.diff-js-api.outputs.message }}
+        with:
+          script: |
+            const postPRComment = require('./.github/workflow-scripts/postPRComment.js');
+            await postPRComment(github, context, {
+              messages: [
+                process.env.API_CHANGES_MESSAGE,
+              ],
+            });
diff --git a/.github/workflows/danger-pr.yml b/.github/workflows/danger-pr.yml
index ce41f6f602cd..f56daaffa826 100644
--- a/.github/workflows/danger-pr.yml
+++ b/.github/workflows/danger-pr.yml
@@ -15,7 +15,7 @@ permissions:
 jobs:
   danger:
     runs-on: ubuntu-latest
-    if: github.repository == 'facebook/react-native'
+    # if: github.repository == 'facebook/react-native'
     steps:
       - name: Check out PR branch
         uses: actions/checkout@v6
@@ -25,8 +25,11 @@ jobs:
         uses: ./.github/actions/yarn-install
       - name: Run diff-js-api-changes
         uses: ./.github/actions/diff-js-api-changes
-      - name: Danger
-        run: yarn danger ci --use-github-checks --failOnErrors
-        working-directory: private/react-native-bots
-        env:
-          DANGER_GITHUB_API_TOKEN: ${{ secrets.REACT_NATIVE_BOT_GITHUB_TOKEN }}
+      - name: Debug - Show API diff output
+        run: cat ${{ runner.temp }}/diff-js-api-changes/output.json
+      # Danger step removed for fork testing
+      # - name: Danger
+      #   run: yarn danger ci --use-github-checks --failOnErrors
+      #   working-directory: private/react-native-bots
+      #   env:
+      #     DANGER_GITHUB_API_TOKEN: ${{ secrets.REACT_NATIVE_BOT_GITHUB_TOKEN }}