diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index c08e82d..bf845a8 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -59,7 +59,8 @@ jobs:
           opam exec -- dune build @install
       - name: test
         run: |
-          opam exec -- dune runtest
+          BISECT_FILE=$(pwd)/bisect opam exec -- dune runtest --force --instrument-with bisect_ppx
+      #   opam exec -- dune runtest
       - name: lint-doc
         run: |
           ODOC_WARN_ERROR=true opam exec -- dune build @doc 2> output.txt || true
diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
new file mode 100644
index 0000000..a92ebd4
--- /dev/null
+++ b/.github/workflows/deploy.yml
@@ -0,0 +1,65 @@
+name: deploy
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  deploy:
+    runs-on: ubuntu-latest
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+        with:
+          persist-credentials: false
+      - name: cache
+        id: cache-opam
+        uses: actions/cache@v4
+        env:
+          cache-name: cache-opam-deploy
+        with:
+          path: |
+            ~/work/ola/ola/_opam/
+          key: ${{ runner.os }}-deploy-${{ env.cache-name }}-${{ hashFiles('**/*.opam') }}
+      - name: setup-ocaml
+        uses: ocaml/setup-ocaml@v3
+        with:
+          ocaml-compiler: "4.14"
+          dune-cache: true
+          opam-pin: true
+          allow-prerelease-opam: false
+    #   - name: depext
+    #     run: |
+    #       sudo apt update
+    #       opam install . --depext-only --with-test --with-doc
+      - name: setup-deploy
+        if: steps.cache-opam.outputs.cache-hit != 'true'
+        run: |
+          opam install . --deps-only --with-test --with-doc
+          opam install bisect_ppx ocb
+    #   - name: api
+    #     run: |
+    #       touch doc/.nojekyll
+    #       opam exec -- dune build @doc
+    #       mv _build/default/_doc/_html doc/api
+      - name: build
+        run: |
+          opam exec -- dune build @install
+      - name: coverage
+        run: |
+          BISECT_FILE=$(pwd)/bisect opam exec -- dune runtest --force --instrument-with bisect_ppx
+          opam exec -- bisect-ppx-report html
+      - name: coverage-badge
+        run: |
+          label=coverage
+          percentage=$(opam exec -- bisect-ppx-report summary | sed -E 's/.*\((..).*/\1/g')
+          color=$(printf "%x%x%x" $((255-$percentage)) $((155+$percentage)) 85)
+          opam exec -- ocb --style classic --label $label --status $percentage'%' --color $color > _coverage/badge.svg
+    #   - name: deploy
+    #     uses: JamesIves/github-pages-deploy-action@v4.6.3
+    #     with:
+    #       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+    #       BRANCH: gh-pages
+    #       FOLDER: doc/
+    #       CLEAN: true
diff --git a/.gitignore b/.gitignore
index a18e084..8fce649 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,7 +9,8 @@
 *.cmxa
 
 # ocamlbuild working directory
-_build/
+_build
+_coverage
 
 # ocamlbuild targets
 *.byte
diff --git a/README.md b/README.md
index 7fce27b..ad0b8d9 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# ola - An OCaml Lua language interpreter
+# ola - An OCaml Lua language interpreter [![build status](https://github.com/epatrizio/ola/workflows/build/badge.svg)](https://github.com/epatrizio/ola/actions)
 
 This project is an interpreter of the [Lua 5.4](https://www.lua.org/manual/5.4/manual.html) programming language
 written in [OCaml](https://ocaml.org) with the [Dune](https://dune.build) build system.
@@ -23,6 +23,11 @@ interprete ...
 Hello, world!
 ```
 
+```sh
+$ bisect-ppx-report summary
+Coverage: 225/1379 (16.32%)
+```
+
 - Install in current [opam OCaml switch](https://ocaml.org/docs/opam-switch-introduction): `dune install`
 - Run: `ola file_name.lua` - `ola file_name.lua --debug`
 
diff --git a/dune-project b/dune-project
index 0daac6b..d1d9d64 100644
--- a/dune-project
+++ b/dune-project
@@ -14,7 +14,8 @@
 
 (maintainers "Eric Patrizio <epatrizio@mpns.fr>")
 
-(source (github epatrizio/ola))
+(source
+ (github epatrizio/ola))
 
 (generate_opam_files true)
 
@@ -23,8 +24,10 @@
 (package
  (name ola)
  (synopsis "OCaml Lua Interpreter")
- (description "OCaml Lua Interpreter. Experimental project, work in progress ...")
- (tags (ola ocaml lua interpreter))
+ (description
+  "OCaml Lua Interpreter. Experimental project, work in progress ...")
+ (tags
+  (ola ocaml lua interpreter))
  (depends
   (ocaml
    (>= 4.14))
@@ -33,6 +36,15 @@
    (and
     :build
     (>= 20220210)))
+  (bisect_ppx
+   (and
+    (>= 2.5)
+    :with-dev-setup))
+  (ocb
+   (and
+    :with-test
+    (>= "0.1")
+    :dev))
   (odoc :with-doc)
   (mdx
    (and
diff --git a/ola.opam b/ola.opam
index 6615a70..0ba2d3f 100644
--- a/ola.opam
+++ b/ola.opam
@@ -14,6 +14,8 @@ depends: [
   "ocaml" {>= "4.14"}
   "sedlex"
   "menhir" {build & >= "20220210"}
+  "bisect_ppx" {>= "2.5" & with-dev-setup}
+  "ocb" {with-test & >= "0.1" & dev}
   "odoc" {with-doc}
   "mdx" {with-test & >= "2.1"}
 ]
diff --git a/src/bisect.exclude b/src/bisect.exclude
new file mode 100644
index 0000000..66bc675
--- /dev/null
+++ b/src/bisect.exclude
@@ -0,0 +1,2 @@
+file "src/parser.ml"
+file "src/lexer.ml"
diff --git a/src/dune b/src/dune
index 9152615..648c2c9 100644
--- a/src/dune
+++ b/src/dune
@@ -17,7 +17,10 @@
   typer)
  (preprocess
   (pps sedlex.ppx))
- (libraries sedlex menhirLib))
+ (libraries sedlex menhirLib)
+ (instrumentation
+  (backend bisect_ppx --exclusions src/bisect.exclude)
+  (deps bisect.exclude)))
 
 (menhir
  (modules parser))