diff --git a/.github/workflows/deploy-client.yml b/.github/workflows/deploy-client.yml
index ca349525536..daaf37891e8 100644
--- a/.github/workflows/deploy-client.yml
+++ b/.github/workflows/deploy-client.yml
@@ -58,48 +58,87 @@ jobs:
       matrix: ${{ steps.matrix.outputs.matrix }}
     steps:
       - name: Setup Matrix
+        uses: actions/github-script@v7
         id: matrix
-        run: |
-          TARGET_LANG="${{ inputs.target_language || 'all' }}"
-          echo "Target language: $TARGET_LANG"
+        env:
+          TARGET_LANG: ${{ inputs.target_language }}
+        with:
+          script: |
+            // Constants
+            const NODE_VERSION = 22;
 
-          if [[ "$TARGET_LANG" == "all" ]]; then
-            # Build all languages
-            MATRIX='{
-              "node-version": [22],
-              "include": [
-                {"lang-name-full": "english", "lang-name-short": "eng"},
-                {"lang-name-full": "chinese", "lang-name-short": "chn"},
-                {"lang-name-full": "espanol", "lang-name-short": "esp"},
-                {"lang-name-full": "chinese-traditional", "lang-name-short": "cnt"},
-                {"lang-name-full": "italian", "lang-name-short": "ita"},
-                {"lang-name-full": "portuguese", "lang-name-short": "por"},
-                {"lang-name-full": "ukrainian", "lang-name-short": "ukr"},
-                {"lang-name-full": "japanese", "lang-name-short": "jpn"},
-                {"lang-name-full": "german", "lang-name-short": "ger"},
-                {"lang-name-full": "swahili", "lang-name-short": "swa"}
-              ]
-            }'
-          else
-            # Build single language
-            case "$TARGET_LANG" in
-              "english") SHORT="eng" ;;
-              "chinese") SHORT="chn" ;;
-              "espanol") SHORT="esp" ;;
-              "chinese-traditional") SHORT="cnt" ;;
-              "italian") SHORT="ita" ;;
-              "portuguese") SHORT="por" ;;
-              "ukrainian") SHORT="ukr" ;;
-              "japanese") SHORT="jpn" ;;
-              "german") SHORT="ger" ;;
-              "swahili") SHORT="swa" ;;
-              *) echo "Error: Unknown language $TARGET_LANG"; exit 1 ;;
-            esac
-            
-            MATRIX="{\"node-version\": [22], \"include\": [{\"lang-name-full\": \"$TARGET_LANG\", \"lang-name-short\": \"$SHORT\"}]}"
-          fi
+            // Input sanitization and validation
+            const rawTargetLang = process.env.TARGET_LANG || 'all';
+            const targetLang = rawTargetLang.trim().toLowerCase();
+            console.log(`Target language: ${targetLang}`);
 
-          echo "matrix=$MATRIX" >> $GITHUB_OUTPUT
+            // Language mappings (single source of truth)
+            const languageMap = {
+              'english': 'eng',
+              'chinese': 'chn',
+              'espanol': 'esp',
+              'chinese-traditional': 'cnt',
+              'italian': 'ita',
+              'portuguese': 'por',
+              'ukrainian': 'ukr',
+              'japanese': 'jpn',
+              'german': 'ger',
+              'swahili': 'swa'
+            };
+
+            const allLanguages = Object.keys(languageMap);
+            let matrix;
+
+            if (targetLang === 'all') {
+              console.log('Building matrix for all languages');
+              console.log(`Available languages: ${allLanguages.join(', ')}`);
+
+              // Build include array for all languages
+              const include = allLanguages.map(lang => ({
+                'node-version': NODE_VERSION,
+                'lang-name-full': lang,
+                'lang-name-short': languageMap[lang]
+              }));
+
+              matrix = {
+                include: include
+              };
+
+            } else {
+              console.log(`Building matrix for single language: ${targetLang}`);
+
+              // Validate language selection
+              if (!languageMap[targetLang]) {
+                const errorMsg = `Unknown language '${targetLang}'. Available: ${allLanguages.join(', ')}`;
+                console.error(errorMsg);
+                core.setFailed(errorMsg);
+                return;
+              }
+
+              console.log(`Processing: ${targetLang} -> ${languageMap[targetLang]}`);
+
+              // Create single language matrix
+              matrix = {
+                include: [{
+                  'node-version': NODE_VERSION,
+                  'lang-name-full': targetLang,
+                  'lang-name-short': languageMap[targetLang]
+                }]
+              };
+            }
+
+            // Final validation
+            if (!matrix || !matrix.include || matrix.include.length === 0) {
+              core.setFailed('Generated matrix is empty or invalid');
+              return;
+            }
+
+            console.log('Generated matrix:');
+            console.log(JSON.stringify(matrix, null, 2));
+            console.log(`Matrix will create ${matrix.include.length} job(s)`);
+
+            // Set output for GitHub Actions
+            core.setOutput('matrix', JSON.stringify(matrix));
 
   client:
     name: Clients - [${{ needs.setup-jobs.outputs.tgt_env_short }}] [${{ matrix.lang-name-short }}]
@@ -107,7 +146,7 @@ jobs:
     runs-on: ubuntu-22.04
     strategy:
       fail-fast: false
-      matrix: ${{ fromJSON(needs.setup-matrix.outputs.matrix) }}
+      matrix: ${{ fromJson(needs.setup-matrix.outputs.matrix) }}
     permissions:
       deployments: write
       contents: read