diff --git a/.github/actions/comment-on-pr/action.yml b/.github/actions/comment-on-pr/action.yml
new file mode 100644
index 000000000..757607287
--- /dev/null
+++ b/.github/actions/comment-on-pr/action.yml
@@ -0,0 +1,35 @@
+name: Comment on PR
+description: Creates or updates a comment on a PR
+inputs:
+  pr-number:
+    description: The number of the PR to comment on
+    required: true
+  comment-search-string:
+    description: String to use to locate a previous comment to update
+    required: true
+  body:
+    description: String to use as the body for the created comment
+    default: ''
+  body-path:
+    description: Path to a file containing the body to use for the created comment
+    default: ''
+outputs: {}
+runs:
+  using: composite
+  steps:
+    - name: Find Existing Comment
+      uses: peter-evans/find-comment@v3
+      id: fc
+      with:
+        issue-number: ${{ inputs.pr-number }}
+        comment-author: 'github-actions[bot]'
+        body-includes: ${{ inputs.comment-search-string }}
+
+    - name: Create or Update Comment
+      uses: peter-evans/create-or-update-comment@v4
+      with:
+        comment-id: ${{ steps.fc.outputs.comment-id }}
+        issue-number: ${{ inputs.pr-number }}
+        body: ${{ inputs.body }}
+        body-path: ${{ inputs.body-path }}
+        edit-mode: replace
\ No newline at end of file
diff --git a/.github/workflows/changes-summary-comment.yml b/.github/workflows/changes-summary-comment.yml
new file mode 100644
index 000000000..3ec2daced
--- /dev/null
+++ b/.github/workflows/changes-summary-comment.yml
@@ -0,0 +1,34 @@
+name: Comment with API Changes Summary
+
+on:
+  workflow_run:
+    workflows: ["Determine API Changes"]
+    types:
+      - completed
+
+jobs:
+  comment:
+    runs-on: ubuntu-latest
+    if: >
+      github.event.workflow_run.event == 'pull_request' &&
+      github.event.workflow_run.conclusion == 'success'
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@v4
+        with:
+          sparse-checkout: |
+            .github
+
+      - name: Download Changes Summary
+        uses: actions/download-artifact@v4
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          name: changes-summary
+          run-id: ${{ github.event.workflow_run.id }}
+
+      - name: 'Comment on PR'
+        uses: ./.github/actions/comment-on-pr
+        with:
+          pr-number: ${{ github.event.workflow_run.pull_requests[0].number }}
+          comment-search-string: '## API Changes Summary'
+          body-path: changes-summary.md
\ No newline at end of file
diff --git a/.github/workflows/determine-changes.yml b/.github/workflows/determine-changes.yml
new file mode 100644
index 000000000..3e8d42706
--- /dev/null
+++ b/.github/workflows/determine-changes.yml
@@ -0,0 +1,117 @@
+name: Determine API Changes
+
+on: [pull_request]
+
+jobs:
+  determine-changes:
+    runs-on: ubuntu-latest
+    permissions:
+      pull-requests: write
+    steps:
+      - name: Checkout Repo
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Determine Branch Point
+        shell: bash -eo pipefail {0}
+        run: |
+          { 
+            echo "BRANCH_POINT_SHA=$(git merge-base "$BASE_SHA" "$HEAD_SHA")"
+            echo "HEAD_SHA=${HEAD_SHA}"
+          } | tee "$GITHUB_ENV"
+        env:
+          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
+          BASE_SHA: ${{ github.event.pull_request.base.sha }}
+
+      - name: Checkout Original Spec
+        shell: bash -eo pipefail {0}
+        run: git checkout $BRANCH_POINT_SHA
+
+      - name: Build Original Spec
+        shell: bash -eo pipefail {0}
+        run: |
+          npm install
+          npm run merge -- --source ./spec --output /tmp/opensearch-openapi-ORIGINAL.yaml
+
+      - name: Checkout Changed Spec
+        shell: bash -eo pipefail {0}
+        run: git checkout $HEAD_SHA
+
+      - name: Build Changed Spec
+        shell: bash -eo pipefail {0}
+        run: |
+          npm install
+          npm run merge -- --source ./spec --output /tmp/opensearch-openapi-CHANGED.yaml
+
+      - name: Install openapi-changes
+        shell: bash -eo pipefail {0}
+        run: npm install --global @pb33f/openapi-changes
+
+      - name: Generate Report
+        shell: bash -eo pipefail {0}
+        run: openapi-changes html-report --no-logo --no-color /tmp/opensearch-openapi-ORIGINAL.yaml /tmp/opensearch-openapi-CHANGED.yaml
+
+      - name: Upload Report
+        id: upload-report
+        uses: actions/upload-artifact@v4
+        with:
+          name: changes-report
+          path: |
+            report.html
+            /tmp/opensearch-openapi-ORIGINAL.yaml
+            /tmp/opensearch-openapi-CHANGED.yaml
+
+      - name: Generate Summary
+        shell: bash -eo pipefail {0}
+        run: |
+          if ! openapi-changes summary --no-logo --no-color --markdown /tmp/opensearch-openapi-ORIGINAL.yaml /tmp/opensearch-openapi-CHANGED.yaml >output.md ; then
+            if ! grep -q 'breaking changes discovered' output.md ; then
+              cat output.md >/dev/stderr
+              exit 1
+            fi
+          fi
+          
+          gawk -v HEAD_SHA="${HEAD_SHA}" -v REPORT_URL="${REPORT_URL}" '
+            BEGIN {
+              print "## API Changes Summary"
+              RS = "(\r|\n|\r\n)"
+              WAS_BLANK = 0
+              HAD_CHANGES = 0
+            }
+            
+            /^starting work/ || /^Building original model/ || /^SPEC: extracted/ || /^ERROR: breaking/ || /^DONE: completed/ {
+              next
+            }
+              
+            /^[[:space:]]*$/ {
+              WAS_BLANK = 1
+              next
+            }
+              
+            WAS_BLANK {
+              WAS_BLANK = 0
+              print ""
+            }
+              
+            {
+              HAD_CHANGES = 1
+              sub(/Commit: New:/, "Commit: " HEAD_SHA ", New:")
+              print
+            }
+          
+            END {
+              if (!HAD_CHANGES) {
+                print "Commit: " HEAD_SHA ", **NO CHANGES**\n"
+              }
+              print "\nFull Report: " REPORT_URL
+            }
+          ' output.md | tee changes-summary.md
+        env:
+          REPORT_URL: ${{ steps.upload-report.outputs.artifact-url }}
+
+      - name: Upload Summary
+        uses: actions/upload-artifact@v4
+        with:
+          name: changes-summary
+          path: changes-summary.md