diff --git a/.secrets.baseline b/.secrets.baseline
index 25406af5..8cc5307d 100644
--- a/.secrets.baseline
+++ b/.secrets.baseline
@@ -3,7 +3,7 @@
     "files": "^.secrets.baseline$",
     "lines": null
   },
-  "generated_at": "2026-01-27T22:16:04Z",
+  "generated_at": "2026-02-24T16:20:06Z",
   "plugins_used": [
     {
       "name": "AWSKeyDetector"
@@ -100,7 +100,7 @@
         "hashed_secret": "ec3810e10fb78db55ce38b9c18d1c3eb1db739e0",
         "is_secret": false,
         "is_verified": false,
-        "line_number": 32,
+        "line_number": 36,
         "type": "Secret Keyword",
         "verified_result": null
       }
@@ -153,6 +153,16 @@
         "verified_result": null
       }
     ],
+    "sandbox/sample.env": [
+      {
+        "hashed_secret": "b792a28a35da9b44fa0ee8a53002e9c238afb1bd",
+        "is_secret": false,
+        "is_verified": false,
+        "line_number": 1,
+        "type": "Secret Keyword",
+        "verified_result": null
+      }
+    ],
     "tests/data/trajectory.json": [
       {
         "hashed_secret": "88de85ead2ab26f647127036827ee7746fcd7514",
diff --git a/sandbox/Dockerfile b/sandbox/Dockerfile
new file mode 100644
index 00000000..5c68146a
--- /dev/null
+++ b/sandbox/Dockerfile
@@ -0,0 +1,40 @@
+FROM debian:bookworm-slim
+
+# Install Linux utilities, Python, and jq
+RUN apt-get update && apt-get install -y \
+    # Basics & editors
+    bash coreutils findutils grep sed gawk less nano vim tree file which procps psmisc sudo \
+    # Networking
+    curl wget ca-certificates iputils-ping dnsutils netcat-traditional iproute2 \
+    # Git + archives
+    git unzip zip tar gzip bzip2 xz-utils \
+    # Build tools
+    build-essential make \
+    # Python
+    python3 python3-venv python3-pip \
+    # JSON parsing
+    jq \
+    && rm -rf /var/lib/apt/lists/*
+
+# Create non-root user
+RUN groupadd sandbox && useradd -m -g sandbox sandbox \
+    && mkdir -p /workspace && chown sandbox:sandbox /workspace
+
+# Create Python venv and make it accessible to sandbox user
+RUN python3 -m venv /opt/claude-venv \
+    && /opt/claude-venv/bin/python -m pip install --upgrade pip \
+    && chown -R sandbox:sandbox /opt/claude-venv
+
+# Install Claude Code as sandbox user
+USER sandbox
+RUN curl -fsSL -o /tmp/install.sh https://claude.ai/install.sh \
+    && bash /tmp/install.sh \
+    && rm /tmp/install.sh
+
+# Add venv + Claude to PATH
+ENV HOME="/home/sandbox"
+ENV PATH="/opt/claude-venv/bin:/home/sandbox/.local/bin:${PATH}"
+
+WORKDIR /workspace
+
+CMD ["bash"]
diff --git a/sandbox/README.md b/sandbox/README.md
new file mode 100644
index 00000000..fed9d8d4
--- /dev/null
+++ b/sandbox/README.md
@@ -0,0 +1,32 @@
+# Claude Code Sandbox
+
+A Docker image for running Claude Code in a sandboxed Debian environment with Python and common Linux tools.
+
+## Build
+
+From the repository root:
+
+```bash
+docker build -t claude-sandbox sandbox/
+```
+
+## Run
+
+1. Copy the sample env file and add your API key:
+
+```bash
+cp sandbox/sample.env sandbox/myenv # edit sandbox/myenv and set your credentials.
+```
+
+2. Run the container, mounting your project into `/workspace`:
+
+```bash
+docker run --rm -it --env-file sandbox/myenv -v "$(pwd)":/workspace claude-sandbox
+```
+
+3. Test that Claude Code is working:
+
+```bash
+docker run --rm --env-file sandbox/myenv claude-sandbox claude -p "who are you"
+```
+
diff --git a/sandbox/sample.env b/sandbox/sample.env
new file mode 100644
index 00000000..640c797c
--- /dev/null
+++ b/sandbox/sample.env
@@ -0,0 +1 @@
+ANTHROPIC_API_KEY=sk-ant-xxxx