diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index 13067d9..f0eba1b 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -6,6 +6,6 @@ RUN apt-get update \
  && apt-get install -y --allow-change-held-packages --no-install-recommends \
       build-essential git \
       r-base r-cran-cairo r-cran-tidyverse \
-      python3 python3-pip python3-numpy python3-matplotlib python3-requests python3-pandas python3-setuptools python3-dev \ 
+      python3 python3-venv python3-pip python3-setuptools python3-dev \ 
  && rm -rf /var/lib/apt/lists/* \
  && apt-get clean
diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index 2995a32..6c1da0a 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -12,12 +12,13 @@
   "hostRequirements": {
     "memory": "16gb"
   },
+  "postCreateCommand": "python3 -m venv /workspaces/demo-codespace/.virtpy; /workspaces/demo-codespace/.virtpy/bin/pip install -r /workspaces/demo-codespace/requirements.txt",
   "customizations": {
     "codespaces": {
       "openFiles": ["welcome.smd"]
     },
     "vscode": {
-      "extensions": ["stencila.stencila"],
+      "extensions": ["usernamehw.errorlens", "stencila.stencila"],
       "settings": {
         // See here for VSCode settings and their defaults
         // https://code.visualstudio.com/docs/getstarted/settings#_default-settings
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..18ed768
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+.virtpy/*
\ No newline at end of file
diff --git a/requirements.txt b/requirements.txt
new file mode 100644
index 0000000..f0c705e
--- /dev/null
+++ b/requirements.txt
@@ -0,0 +1,3 @@
+requests
+pandas
+matplotlib
\ No newline at end of file