diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index 8ae0563..faab0cd 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -49,7 +49,6 @@ jobs:
           - geos-trame
           - geos-utils
           - geos-xml-tools
-          - geos-xml-viewer
           - hdf5-wrapper
           - pygeos-tools
         include:
@@ -98,4 +97,241 @@ jobs:
       run:
       # python -m pytest ./${{ matrix.package-name }} --doctest-modules --junitxml=junit/test-results.xml --cov-report=xml --cov-report=html |
       # wrap pytest to avoid error when no tests in the package
-        sh -c 'python -m pytest ./${{ matrix.package-name }}; ret=$?; [ $ret = 5 ] && exit 0 || exit $ret'
\ No newline at end of file
+        sh -c 'python -m pytest ./${{ matrix.package-name }}; ret=$?; [ $ret = 5 ] && exit 0 || exit $ret'
+
+  # Step 1: Validate that all standard CI tests pass BEFORE checking GEOS integration
+  validate_standard_ci:
+    runs-on: ubuntu-latest
+    needs: [semantic_pull_request, build]
+    steps:
+    - name: Check standard CI results
+      run: |
+        echo "Checking standard CI results..."
+        echo "Semantic PR check: ${{ needs.semantic_pull_request.result }}"
+        echo "Build and test: ${{ needs.build.result }}"
+        
+        # All standard tests must pass before proceeding
+        if [[ "${{ needs.semantic_pull_request.result }}" != "success" ]]; then
+          echo "❌ Semantic PR check failed - fix PR title before proceeding"
+          exit 1
+        fi
+        
+        if [[ "${{ needs.build.result }}" != "success" ]]; then
+          echo "❌ Build and test failed - fix code issues before proceeding"
+          exit 1
+        fi
+        
+        echo "✅ All standard CI tests passed! Ready for GEOS integration testing."
+
+  # Step 2: Only after standard tests pass, check for GEOS integration label
+  check_geos_integration_label:
+    runs-on: ubuntu-latest
+    needs: [validate_standard_ci]
+    outputs:
+      should_test_geos: ${{ steps.check_label.outputs.should_test_geos }}
+      has_label: ${{ steps.check_label.outputs.has_label }}
+    steps:
+    - name: Check for GEOS integration test label
+      id: check_label
+      run: |
+        echo "Standard CI tests have passed. Now checking for GEOS integration requirements..."
+        
+        # Check if the PR has the 'test-geos-integration' label
+        pr_json=$(curl -H "Accept: application/vnd.github+json" \
+                       -H "Authorization: Bearer ${{ secrets.GITHUB_TOKEN }}" \
+                       https://api.github.com/repos/${{ github.repository }}/pulls/${{ github.event.number }})
+        
+        LABELS=$(echo ${pr_json} | jq -r '[.labels[].name] | join(",")')
+        echo "PR labels: ${LABELS}"
+        
+        if [[ "${LABELS}" == *"test-geos-integration"* ]]; then
+          echo "has_label=true" >> $GITHUB_OUTPUT
+          echo "should_test_geos=true" >> $GITHUB_OUTPUT
+          echo "✅ Found 'test-geos-integration' label - will proceed with GEOS integration testing"
+        else
+          echo "has_label=false" >> $GITHUB_OUTPUT
+          echo "should_test_geos=false" >> $GITHUB_OUTPUT
+          echo "❌ Missing 'test-geos-integration' label"
+          echo ""
+          echo "REQUIRED: This PR must have the 'test-geos-integration' label to be merged"
+          echo "This ensures that changes are tested against GEOS before merging"
+          echo ""
+          echo "To add the label:"
+          echo "1. Go to your PR page"
+          echo "2. Click on 'Labels' in the right sidebar" 
+          echo "3. Add the 'test-geos-integration' label"
+        fi
+
+  # Step 3: Only trigger GEOS integration if label exists AND standard tests passed
+  trigger_geos_integration_test:
+    runs-on: ubuntu-latest
+    needs: [check_geos_integration_label]
+    if: needs.check_geos_integration_label.outputs.should_test_geos == 'true'
+    outputs:
+      workflow_run_id: ${{ steps.trigger_workflow.outputs.workflow_run_id }}
+    steps:
+    - name: Get PR information
+      id: pr_info
+      run: |
+        echo "Triggering GEOS integration test..."
+        pr_json=$(curl -H "Accept: application/vnd.github+json" \
+                       -H "Authorization: Bearer ${{ secrets.GITHUB_TOKEN }}" \
+                       https://api.github.com/repos/${{ github.repository }}/pulls/${{ github.event.number }})
+        
+        PR_HEAD_REPO=$(echo ${pr_json} | jq -r '.head.repo.clone_url')
+        PR_HEAD_BRANCH=$(echo ${pr_json} | jq -r '.head.ref')
+        PR_HEAD_SHA=$(echo ${pr_json} | jq -r '.head.sha')
+        
+        echo "pr_repo=${PR_HEAD_REPO}" >> $GITHUB_OUTPUT
+        echo "pr_branch=${PR_HEAD_BRANCH}" >> $GITHUB_OUTPUT
+        echo "pr_sha=${PR_HEAD_SHA}" >> $GITHUB_OUTPUT
+        
+        echo "PR Repository: ${PR_HEAD_REPO}"
+        echo "PR Branch: ${PR_HEAD_BRANCH}"
+        echo "PR SHA: ${PR_HEAD_SHA}"
+
+    - name: Trigger GEOS integration test workflow
+      id: trigger_workflow
+      run: |
+        echo "All standard tests passed ✅"
+        echo "GEOS integration label found ✅"
+        echo "Now triggering GEOS integration test workflow..."
+        
+        # Trigger the workflow_dispatch event in the GEOS repository
+        response=$(curl -X POST \
+          -H "Accept: application/vnd.github+json" \
+          -H "Authorization: Bearer ${{ secrets.GEOS_INTEGRATION_TOKEN }}" \
+          -H "X-GitHub-Api-Version: 2022-11-28" \
+          https://api.github.com/repos/GEOS-DEV/GEOS/actions/workflows/test_geospythonpackages_integration.yml/dispatches \
+          -d '{
+            "ref": "develop",
+            "inputs": {
+              "python_package_repo": "${{ steps.pr_info.outputs.pr_repo }}",
+              "python_package_branch": "${{ steps.pr_info.outputs.pr_branch }}",
+              "python_package_pr": "${{ github.event.number }}",
+              "requested_by": "${{ github.actor }}"
+            }
+          }')
+        
+        echo "Workflow dispatch response: $response"
+        echo "✅ GEOS integration test workflow triggered successfully"
+        
+        # Wait a moment for the workflow to start, then find the run ID
+        sleep 10
+        
+        # Get the latest workflow runs to find our triggered run
+        runs_response=$(curl -H "Accept: application/vnd.github+json" \
+                             -H "Authorization: Bearer ${{ secrets.GEOS_INTEGRATION_TOKEN }}" \
+                             https://api.github.com/repos/GEOS-DEV/GEOS/actions/workflows/test_geospythonpackages_integration.yml/runs?per_page=5)
+        
+        # Find the most recent run (this assumes it's our triggered run)
+        workflow_run_id=$(echo "$runs_response" | jq -r '.workflow_runs[0].id')
+        echo "workflow_run_id=${workflow_run_id}" >> $GITHUB_OUTPUT
+        echo "Triggered workflow run ID: ${workflow_run_id}"
+
+  # Step 4: Wait for GEOS integration results (only if triggered)
+  wait_for_geos_integration_result:
+    runs-on: ubuntu-latest
+    needs: [trigger_geos_integration_test]
+    if: needs.trigger_geos_integration_test.outputs.workflow_run_id != ''
+    outputs:
+      geos_test_result: ${{ steps.wait_for_result.outputs.geos_test_result }}
+    steps:
+    - name: Wait for GEOS integration test to complete
+      id: wait_for_result
+      run: |
+        WORKFLOW_RUN_ID="${{ needs.trigger_geos_integration_test.outputs.workflow_run_id }}"
+        echo "Waiting for GEOS integration test to complete (Run ID: ${WORKFLOW_RUN_ID})..."
+        echo "This may take 15-30 minutes..."
+        
+        # Wait for the workflow to complete (with timeout)
+        timeout=1800  # 30 minutes
+        elapsed=0
+        interval=30
+        
+        while [ $elapsed -lt $timeout ]; do
+          run_status=$(curl -H "Accept: application/vnd.github+json" \
+                           -H "Authorization: Bearer ${{ secrets.GEOS_INTEGRATION_TOKEN }}" \
+                           https://api.github.com/repos/GEOS-DEV/GEOS/actions/runs/${WORKFLOW_RUN_ID} \
+                           | jq -r '.status')
+          
+          conclusion=$(curl -H "Accept: application/vnd.github+json" \
+                           -H "Authorization: Bearer ${{ secrets.GEOS_INTEGRATION_TOKEN }}" \
+                           https://api.github.com/repos/GEOS-DEV/GEOS/actions/runs/${WORKFLOW_RUN_ID} \
+                           | jq -r '.conclusion')
+          
+          echo "Workflow status: ${run_status}, conclusion: ${conclusion} (${elapsed}s elapsed)"
+          
+          if [[ "${run_status}" == "completed" ]]; then
+            echo "Workflow completed with conclusion: ${conclusion}"
+            
+            if [[ "${conclusion}" == "success" ]]; then
+              echo "✅ GEOS integration test PASSED"
+              echo "geos_test_result=success" >> $GITHUB_OUTPUT
+              exit 0
+            else
+              echo "❌ GEOS integration test FAILED"
+              echo "geos_test_result=failure" >> $GITHUB_OUTPUT
+              exit 1
+            fi
+          fi
+          
+          sleep $interval
+          elapsed=$((elapsed + interval))
+        done
+        
+        echo "❌ TIMEOUT: GEOS integration test did not complete within ${timeout} seconds"
+        echo "geos_test_result=timeout" >> $GITHUB_OUTPUT
+        exit 1
+
+  # Step 5: Final validation - requires ALL tests to pass
+  final_validation:
+    runs-on: ubuntu-latest
+    needs: [check_geos_integration_label, wait_for_geos_integration_result]
+    if: always()
+    steps:
+    - name: Final merge validation
+      run: |
+        echo "=== FINAL MERGE VALIDATION ==="
+        echo ""
+        echo "Standard CI Tests: ✅ PASSED (already validated)"
+        echo "GEOS Integration Label: ${{ needs.check_geos_integration_label.outputs.has_label == 'true' && '✅ PRESENT' || '❌ MISSING' }}"
+        echo "GEOS Integration Tests: ${{ needs.wait_for_geos_integration_result.outputs.geos_test_result == 'success' && '✅ PASSED' || needs.wait_for_geos_integration_result.result == 'skipped' && '⏭️ SKIPPED (no label)' || '❌ FAILED' }}"
+        echo ""
+        
+        # Check label requirement
+        if [[ "${{ needs.check_geos_integration_label.outputs.has_label }}" != "true" ]]; then
+          echo "❌ INVALID: Missing 'test-geos-integration' label"
+          echo ""
+          echo "This PR cannot be merged without the 'test-geos-integration' label"
+          echo "Please add the label and wait for GEOS integration tests to pass"
+          exit 1
+        fi
+        
+        # Check GEOS test results (only if they were supposed to run)
+        if [[ "${{ needs.wait_for_geos_integration_result.result }}" == "failure" || "${{ needs.wait_for_geos_integration_result.outputs.geos_test_result }}" == "failure" ]]; then
+          echo "❌ INVALID: GEOS integration tests failed"
+          echo ""
+          echo "The changes in this PR break GEOS functionality"
+          echo "Please check the GEOS workflow logs and fix the issues"
+          echo "GEOS workflow: https://github.com/GEOS-DEV/GEOS/actions/runs/${{ needs.trigger_geos_integration_test.outputs.workflow_run_id }}"
+          exit 1
+        fi
+        
+        if [[ "${{ needs.wait_for_geos_integration_result.outputs.geos_test_result }}" == "timeout" ]]; then
+          echo "❌ INVALID: GEOS integration tests timed out"
+          echo ""
+          echo "Please check the GEOS workflow manually and re-run if needed"
+          echo "GEOS workflow: https://github.com/GEOS-DEV/GEOS/actions/runs/${{ needs.trigger_geos_integration_test.outputs.workflow_run_id }}"
+          exit 1
+        fi
+        
+        # All validations passed
+        echo "✅ VALID: All requirements met"
+        echo ""
+        echo "This PR is ready for review and merge:"
+        echo "  ✅ Standard CI tests passed"
+        echo "  ✅ 'test-geos-integration' label present"
+        echo "  ✅ GEOS integration tests passed"
+        echo ""
+        echo "🎉 Ready for merge!"
\ No newline at end of file
diff --git a/GEOS_INTEGRATION_TESTING.md b/GEOS_INTEGRATION_TESTING.md
new file mode 100644
index 0000000..1d2e147
--- /dev/null
+++ b/GEOS_INTEGRATION_TESTING.md
@@ -0,0 +1,190 @@
+# geosPythonPackages and GEOS Integration Testing
+
+This document explains the new CI requirements for geosPythonPackages contributors to ensure compatibility with GEOS.
+
+## ⚠️ IMPORTANT: New CI Requirements
+
+Starting now, all PRs to geosPythonPackages **MUST** pass GEOS integration testing before they can be merged.
+
+## Quick Start Guide
+
+### For Every PR, you must:
+
+1. ✅ **Ensure standard CI tests pass first** (semantic check, build, lint, test)
+2. ✅ **Add the `test-geos-integration` label** to your PR (only after standard tests pass)
+3. ✅ **Wait for GEOS integration tests** to pass
+4. ✅ **Fix any issues** if GEOS tests fail
+
+## The Complete Workflow Sequence
+
+The CI now follows this **strict sequence**:
+
+### 1️⃣ Standard CI Tests (MUST pass first)
+- ✅ Semantic PR title check
+- ✅ Build and install all packages
+- ✅ Lint with yapf
+- ✅ Test with pytest
+
+**⚠️ Until these pass, GEOS integration testing will NOT start**
+
+### 2️⃣ Label Check (after standard tests pass)
+- 🏷️ Check for `test-geos-integration` label
+- ❌ **FAIL** if label is missing
+- ✅ **PROCEED** if label is present
+
+### 3️⃣ GEOS Integration Testing (triggered automatically)
+- 🔗 Trigger GEOS CI with your branch
+- ⏱️ Wait for GEOS tests to complete (15-30 minutes)
+- ✅ **PASS** if GEOS tests succeed
+- ❌ **FAIL** if GEOS tests fail
+
+### 4️⃣ Final Validation
+- ✅ **VALID** = Standard tests ✅ + Label ✅ + GEOS tests ✅
+- ❌ **INVALID** = Any step fails
+
+## Developer Workflow
+
+### Step-by-Step Process:
+
+#### 1. Create Your PR and Iterate
+```bash
+# Create your branch and make changes
+git checkout -b fix/my-awesome-feature
+# ... make changes ...
+git push origin fix/my-awesome-feature
+```
+
+#### 2. Wait for Standard CI to Pass
+- **Don't add the label yet!**
+- Let the standard CI tests run first
+- Fix any issues with:
+  - PR title formatting
+  - Build errors
+  - Lint issues
+  - Test failures
+- Push fixes and wait for tests to pass
+
+#### 3. Add Label (Only After Standard Tests Pass)
+- Go to your PR page
+- In the right sidebar, find "Labels"
+- Add the label: `test-geos-integration`
+- This triggers the GEOS integration sequence
+
+#### 4. Monitor GEOS Integration Results
+- The workflow will automatically trigger GEOS CI
+- You'll see progress in the "geosPythonPackages CI" workflow
+- Wait for results (can take 15-30 minutes)
+
+#### 5. Address Any GEOS Failures
+If GEOS integration fails:
+- Check the workflow logs for details
+- Fix the issues in your branch
+- Push the fixes
+- The process will restart from step 1
+
+## What Gets Tested in GEOS Integration
+
+The GEOS integration test validates:
+- ✅ geosPythonPackages can be installed by GEOS
+- ✅ Key tools work: `preprocess_xml`, `format_xml`, `mesh-doctor`
+- ✅ Python packages can be imported: `geos_utils`, `geos_mesh`, etc.
+- ✅ XML preprocessing functionality works
+- ✅ No API breaking changes
+
+## Understanding CI Results
+
+### ✅ VALID (Green) ✅
+All requirements met:
+- Standard CI tests passed
+- `test-geos-integration` label present
+- GEOS integration tests passed
+- **Ready for review/merge**
+
+### ❌ INVALID (Red) ❌
+One or more requirements failed:
+- Standard CI tests failed
+- Label missing
+- GEOS integration tests failed
+- **Cannot be merged**
+
+## Common Scenarios
+
+### Scenario 1: Standard Tests Failing
+```
+❌ Standard CI Tests → ⏸️ Label Check Skipped → ⏸️ GEOS Tests Skipped
+```
+**Action**: Fix your code first, don't add the label yet
+
+### Scenario 2: Standard Tests Pass, No Label
+```
+✅ Standard CI Tests → ❌ Label Missing → ⏸️ GEOS Tests Skipped  
+```
+**Action**: Add the `test-geos-integration` label
+
+### Scenario 3: All Standard Tests Pass, Label Added
+```
+✅ Standard CI Tests → ✅ Label Present → 🔄 GEOS Tests Running
+```
+**Action**: Wait for GEOS tests to complete
+
+### Scenario 4: GEOS Tests Fail
+```
+✅ Standard CI Tests → ✅ Label Present → ❌ GEOS Tests Failed
+```
+**Action**: Fix the breaking changes, push updates
+
+### Scenario 5: Everything Passes
+```
+✅ Standard CI Tests → ✅ Label Present → ✅ GEOS Tests Passed → ✅ READY
+```
+**Action**: Proceed with normal code review
+
+## Benefits of This Approach
+
+1. **🚀 Faster Iteration**: Fix basic issues first without expensive GEOS testing
+2. **💰 Cost Efficient**: Only run GEOS CI when standard tests pass
+3. **🎯 Clear Sequence**: Developers know exactly when to add the label
+4. **🛡️ Protected GEOS**: No breaking changes reach GEOS
+5. **📈 Better Feedback**: Clear status at each step
+
+## Tips for Contributors
+
+### DO ✅
+- ✅ Let standard CI pass completely before adding the label
+- ✅ Fix all basic issues (build, lint, test) first
+- ✅ Add the label only when standard tests are green
+- ✅ Monitor the GEOS integration progress
+- ✅ Fix GEOS-related issues promptly
+
+### DON'T ❌
+- ❌ Add the label immediately when creating the PR
+- ❌ Add the label while standard tests are still failing
+- ❌ Ignore GEOS test failures
+- ❌ Remove and re-add the label unnecessarily
+
+## Getting Help
+
+### If you need help:
+1. Check the workflow logs for specific error messages
+2. Look at the [detailed documentation](https://github.com/GEOS-DEV/GEOS/blob/develop/src/docs/GEOS_PYTHON_INTEGRATION_TESTING.md)
+3. Ask in the GEOS-DEV team channels
+
+### Manual Testing:
+You can manually trigger GEOS integration testing:
+1. Go to [GEOS Actions](https://github.com/GEOS-DEV/GEOS/actions)
+2. Find "Test GEOS Integration from geosPythonPackages"
+3. Click "Run workflow" and specify your branch
+
+## Summary
+
+| Step | Status | Next Action |
+|------|--------|-------------|
+| 1. Standard CI | ❌ Failed | Fix code issues |
+| 1. Standard CI | ✅ Passed | Add `test-geos-integration` label |
+| 2. Label Check | ❌ Missing | Add the label |
+| 2. Label Check | ✅ Present | Wait for GEOS tests |
+| 3. GEOS Tests | 🔄 Running | Wait (15-30 min) |
+| 3. GEOS Tests | ❌ Failed | Fix breaking changes |
+| 3. GEOS Tests | ✅ Passed | Ready for review! |
+
+**Remember**: The sequence is strictly enforced - standard tests MUST pass before GEOS integration testing begins!