diff --git a/forum/env/setup-debian.sh b/forum/env/setup-debian.sh
new file mode 100755
index 0000000..a5afd81
--- /dev/null
+++ b/forum/env/setup-debian.sh
@@ -0,0 +1,41 @@
+#!/bin/bash
+set -e
+
+# 1. Install system compilers, libraries, and package managers
+# Note: Debian/Ubuntu packages npm separately from nodejs and names Clang headers libclang-dev
+sudo apt-get update -qq
+sudo apt-get install -y \
+  build-essential \
+  pkg-config \
+  clang \
+  libclang-dev \
+  graphviz \
+  pipx \
+  nodejs \
+  npm -qq
+
+# 2. Add local tool paths to ~/.bashrc and active shell
+pipx ensurepath
+export PATH="$HOME/.cargo/bin:$HOME/.local/bin:$PATH"
+grep -q 'export PATH="\$HOME/.cargo/bin:\$HOME/.local/bin:\$PATH"' ~/.bashrc || \
+  echo 'export PATH="$HOME/.cargo/bin:$HOME/.local/bin:$PATH"' >> ~/.bashrc
+
+# 3. Install CLI binaries
+# Cargo compiles native Tree-sitter using libclang-dev
+cargo install tree-sitter-cli
+pipx install semgrep
+pipx install mutmut
+
+# Handle global npm install (avoids sudo if running under nvm)
+if command -v nvm >/dev/null 2>&1 || [ -n "$NVM_DIR" ]; then
+  npm install -g @sourcegraph/scip-typescript madge @stryker-mutator/core
+else
+  sudo npm install -g @sourcegraph/scip-typescript madge @stryker-mutator/core
+fi
+
+# 4. Verify all commands exist
+tree-sitter --version && \
+semgrep --version && \
+scip-typescript --version && \
+madge --version && \
+mutmut --version