diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index e527e30..02d4ef7 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -25,13 +25,14 @@ jobs:
       - name: Install dependencies
         run: |
           dart pub global activate melos
+          dart pub global activate coverage
           melos bootstrap
 
       - name: Setup integration test
         run: ./scripts/setup_integration_tests.sh
 
-      - name: Run tests
-        run: melos run test 
+      - name: Run tests with coverage
+        run: melos run test:coverage 
 
       - name: Run petstore integration tests
         run: |
@@ -140,3 +141,56 @@ jobs:
           cd integration_test/server_variables/server_variables_test
           dart pub get
           dart test --concurrency=1
+      - name: Format and merge coverage reports
+        if: matrix.sdk == 'stable'
+        run: |
+          # Ensure output directory exists before format_coverage writes files
+          mkdir -p coverage
+          
+          # Process each package separately to maintain correct source file paths (packages/*/lib)
+          dart pub global run coverage:format_coverage \
+            --lcov \
+            --in=packages/tonik/coverage \
+            --out=coverage/tonik.lcov.info \
+            --report-on=packages/tonik/lib \
+            --check-ignore || true
+          
+          dart pub global run coverage:format_coverage \
+            --lcov \
+            --in=packages/tonik_core/coverage \
+            --out=coverage/tonik_core.lcov.info \
+            --report-on=packages/tonik_core/lib \
+            --check-ignore || true
+          
+          dart pub global run coverage:format_coverage \
+            --lcov \
+            --in=packages/tonik_generate/coverage \
+            --out=coverage/tonik_generate.lcov.info \
+            --report-on=packages/tonik_generate/lib \
+            --check-ignore || true
+          
+          dart pub global run coverage:format_coverage \
+            --lcov \
+            --in=packages/tonik_parse/coverage \
+            --out=coverage/tonik_parse.lcov.info \
+            --report-on=packages/tonik_parse/lib \
+            --check-ignore || true
+          
+          dart pub global run coverage:format_coverage \
+            --lcov \
+            --in=packages/tonik_util/coverage \
+            --out=coverage/tonik_util.lcov.info \
+            --report-on=packages/tonik_util/lib \
+            --check-ignore || true
+          
+          # Combine per-package reports into single file for codecov upload
+          cat coverage/*.lcov.info > coverage/lcov.info 2>/dev/null || echo "No coverage files found"
+
+      - name: Upload coverage to Codecov
+        if: matrix.sdk == 'stable'
+        uses: codecov/codecov-action@v5
+        with:
+          files: ./coverage/lcov.info
+          fail_ci_if_error: false
+          disable_search: true
+          token: ${{ secrets.CODECOV_TOKEN }}
\ No newline at end of file
diff --git a/codecov.yml b/codecov.yml
new file mode 100644
index 0000000..97ccf9d
--- /dev/null
+++ b/codecov.yml
@@ -0,0 +1,48 @@
+codecov:
+  require_ci_to_pass: false
+
+coverage:
+  precision: 2
+  round: down
+  range: "0...100"
+  
+  status:
+    project:
+      default:
+        informational: true
+        target: auto
+    
+    patch:
+      default:
+        informational: true
+        target: auto
+
+ignore:
+  - "integration_test/**"
+  - "**/test/**"
+  - "**/*.g.dart"
+  - "**/*.freezed.dart"
+
+comment:
+  layout: "reach,diff,flags,tree,files"
+  behavior: default
+  require_changes: false
+  require_base: false
+  require_head: true
+
+flags:
+  tonik:
+    paths:
+      - packages/tonik/lib
+  tonik_core:
+    paths:
+      - packages/tonik_core/lib
+  tonik_generate:
+    paths:
+      - packages/tonik_generate/lib
+  tonik_parse:
+    paths:
+      - packages/tonik_parse/lib
+  tonik_util:
+    paths:
+      - packages/tonik_util/lib
diff --git a/pubspec.yaml b/pubspec.yaml
index 20aa257..0f1f364 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -18,6 +18,7 @@ dependencies:
   path: ^1.9.1
 
 dev_dependencies:
+  coverage: ^1.10.0
   melos: ^7.3.0
   test: ^1.28.0
   timezone: ^0.11.0
@@ -29,6 +30,11 @@ melos:
       run: dart test
       exec:
         concurrency: 1
+
+    test:coverage:
+      run: dart test --coverage=coverage
+      exec:
+        concurrency: 1
         
     generate:
       run: flutter pub run build_runner build --delete-conflicting-outputs