diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
new file mode 100644
index 0000000..41a4f13
--- /dev/null
+++ b/.devcontainer/devcontainer.json
@@ -0,0 +1,25 @@
+{
+  "name": "MemPalace",
+  "image": "mcr.microsoft.com/devcontainers/python:3.11",
+  "features": {
+    "ghcr.io/devcontainers/features/github-cli:1": {}
+  },
+  "postCreateCommand": "bash .devcontainer/post-create.sh",
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "ms-python.python",
+        "ms-python.debugpy",
+        "charliermarsh.ruff"
+      ],
+      "settings": {
+        "python.defaultInterpreterPath": "/usr/local/bin/python",
+        "python.testing.pytestEnabled": true,
+        "python.testing.pytestArgs": ["tests/", "-v", "--ignore=tests/benchmarks"],
+        "ruff.importStrategy": "fromEnvironment",
+        "editor.formatOnSave": true,
+        "editor.defaultFormatter": "charliermarsh.ruff"
+      }
+    }
+  }
+}
diff --git a/.devcontainer/post-create.sh b/.devcontainer/post-create.sh
new file mode 100755
index 0000000..c9a5c0e
--- /dev/null
+++ b/.devcontainer/post-create.sh
@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+echo "=== MemPalace Dev Container Setup ==="
+
+pip install -e ".[dev]"
+
+# Match CI's ruff pin (pyproject only sets a floor; without this contributors
+# get a newer ruff locally than CI runs, causing phantom lint failures).
+pip install "ruff>=0.4.0,<0.5"
+
+pip install pre-commit
+pre-commit install
+
+echo ""
+echo "=== Verification ==="
+echo "python: $(python --version)"
+echo "pytest: $(python -m pytest --version 2>&1 | head -1)"
+echo "ruff:   $(python -m ruff --version 2>&1 | head -1)"
+echo ""
+echo "Ready. Run: pytest tests/ -v --ignore=tests/benchmarks"