diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 96afd9b9..6482d033 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -67,3 +67,10 @@ jobs:
       - name: ${{ matrix.name }}
         run: |
           ${{ matrix.command }}
+      - if: matrix.step == 'test'
+        name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v3
+        with:
+          flags: unittests
+          file: cover.out
+          fail_ci_if_error: true
diff --git a/codecov.yaml b/codecov.yaml
new file mode 100644
index 00000000..e07c8a72
--- /dev/null
+++ b/codecov.yaml
@@ -0,0 +1,36 @@
+# https://docs.codecov.com/docs/commit-status
+coverage:
+  status:
+    project:
+      # global coverage
+      default:
+        target: auto
+        threshold: 2%
+        flags:
+          - unittests
+        paths:
+          - "pkg"
+        if_ci_failed: error
+        if_no_uploads: error
+        if_not_found: success
+    patch:
+      # diff coverage
+      default:
+        target: 70%
+        flags:
+          - unittests
+        paths:
+          - "pkg"
+        informational: true
+        if_ci_failed: ignore
+        if_no_uploads: success
+        if_not_found: success
+
+ignore:
+  - "apis"
+  - "yarn/client"
+  - "yarn/apis"
+  - "**/*_generated.*"
+
+github_checks:
+  annotations: true