diff --git a/.github/workflows/cicd.yaml b/.github/workflows/cicd.yaml
index a458905..8b5351e 100644
--- a/.github/workflows/cicd.yaml
+++ b/.github/workflows/cicd.yaml
@@ -15,7 +15,22 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
+      # https://github.com/scoverage/sbt-coveralls#github-actions-integration
+#      - name: Git checkout (merge)
+      - uses: actions/checkout@v3
+#        if: github.event_name != 'pull_request'
+#        with:
+#          fetch-depth: 0
+#
+#      - name: Git checkout (PR)
+#        uses: actions/checkout@v3
+#        if: github.event_name == 'pull_request'
+#        with:
+#          fetch-depth: 0
+#          # see: https://frontside.com/blog/2020-05-26-github-actions-pull_request/#how-does-pull_request-affect-actionscheckout
+#          ref: ${{ github.event.pull_request.head.sha }}
+      ###
+
       - uses: olafurpg/setup-scala@v13
 
       - name: Cache sbt
@@ -30,8 +45,8 @@ jobs:
             ~/Library/Caches/Coursier/v1
           key: ${{ runner.os }}-sbt-cache-v2-${{ hashFiles('**/*.sbt') }}-${{ hashFiles('project/build.properties') }}
 
-      - name: test
-        run: sbt ";clean;Test/compile;test"
+      - name: run tests
+        run: sbt ";clean;Test/compile;coverage;test"
 
       - name: detailed test reporting
         uses: dorny/test-reporter@v1
@@ -56,8 +71,7 @@ jobs:
           job_summary: false
 
       - name: test coverage
-        # TODO: Use coveralls
-        run: echo "test coverage"
+        run: sbt coverageReport coveralls
         env:
           COVERALLS_REPO_TOKEN: ${{ secrets.COVERALLS_REPO_TOKEN }}
 
diff --git a/README.md b/README.md
index 5b112ec..9d988cc 100644
--- a/README.md
+++ b/README.md
@@ -2,6 +2,8 @@
 
 [![Latest Release](https://badgen.net/github/release/NikinAI/TypedGraph)](https://github.com/NikinAI/TypedGraph/packages)
 
+[![Coverage Status](https://coveralls.io/repos/github/NikinAI/TypedGraph/badge.svg?branch=main)](https://coveralls.io/github/NikinAI/TypedGraph?branch=main)
+
 ---
 
 A library to describe **Typed Condensed Oriented Directed Acyclic Planar Multigraphs**.
diff --git a/build.sbt b/build.sbt
index eb99702..6293dec 100644
--- a/build.sbt
+++ b/build.sbt
@@ -2,7 +2,7 @@ lazy val root =
   project
     .in(file("."))
     .enablePlugins(GitVersioning)
-.    enablePlugins(BuildInfoPlugin)
+    .enablePlugins(BuildInfoPlugin)
     .settings(
       scalaVersion                           := "2.13.10",
       name                                   := "Typed Graph",
@@ -26,13 +26,13 @@ lazy val root =
           "-Ywarn-unused:params", "-Ywarn-unused:locals", "-Ywarn-value-discard",
           "-Ywarn-unused:privates",
         ),
-
-
+      coverageEnabled                        := true,
+      CoverallsKeys.coberturaFile := crossTarget.value / "coverage-report" / "cobertura.xml",
 
       // https://github.com/target/data-validator/blob/d3ae90ea1c84d922e50ad097f517e44852711c1c/build.sbt#LL11-L12C27
       git.useGitDescribe := true,
       // https://github.com/target/data-validator/blob/d3ae90ea1c84d922e50ad097f517e44852711c1c/build.sbt#LL27
-      publishTo := githubPublishTo.value,
+      publishTo          := githubPublishTo.value,
 
       // https://github.com/djspiewak/sbt-github-packages#usage
       githubOwner       := "NikinAI",
diff --git a/project/plugins.sbt b/project/plugins.sbt
index a756beb..03714c2 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -4,3 +4,8 @@ addSbtPlugin("com.codecommit" % "sbt-github-packages" % "0.5.3")
 // https://github.com/target/data-validator/blob/d3ae90ea1c84d922e50ad097f517e44852711c1c/project/plugins.sbt#LL3
 addSbtPlugin("com.github.sbt" % "sbt-git" % "2.0.0")
 addSbtPlugin("com.eed3si9n" % "sbt-buildinfo" % "0.11.0")
+
+// https://github.com/scoverage/sbt-scoverage
+addSbtPlugin("org.scoverage" % "sbt-scoverage" % "2.0.5")
+// https://github.com/scoverage/sbt-coveralls
+addSbtPlugin("org.scoverage" % "sbt-coveralls" % "1.3.3")