diff --git a/Dockerfile b/Dockerfile
index 98d1fa7..9f2c6e6 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -9,6 +9,13 @@ RUN pip install "json2args[data]>=0.6.2"
 # with less dependencies
 # RUN pip install json2args>=0.6.2
 
+# Build spec binary from source
+RUN apt-get update && apt-get install -y golang-go git && \
+    git clone https://github.com/hydrocode-de/gotap.git /tmp/gotap && \
+    cd /tmp/gotap && go build -o /usr/local/bin/spec ./main.go && \
+    rm -rf /tmp/gotap && \
+    apt-get remove -y golang-go git && apt-get autoremove -y && apt-get clean
+
 # Do anything you need to install tool dependencies here
 RUN echo "Replace this line with a tool"
 
@@ -23,4 +30,4 @@ COPY ./src /src
 COPY ./CITATION.cf[f] /src/CITATION.cff
 
 WORKDIR /src
-CMD ["python", "run.py"]
+CMD ["spec", "run", "foobar", "--input-file", "/in/input.json"]
diff --git a/src/tool.yml b/src/tool.yml
index d567cd8..3a3b3b3 100644
--- a/src/tool.yml
+++ b/src/tool.yml
@@ -2,6 +2,7 @@ tools:
   foobar:
     title: Foo Bar
     description: A dummy tool to exemplify the YAML file
+    command: "python run.py"
     parameters:
       foo_int: 
         type: integer