diff --git a/justfile b/justfile
new file mode 100644
index 0000000..b50e250
--- /dev/null
+++ b/justfile
@@ -0,0 +1,22 @@
+set shell := ["bash", "-c"]
+
+default: check
+
+[private]
+_ensure_tools:
+    @mise trust --yes . 2>/dev/null; mise install --quiet
+
+# Run all checks (fmt, lint)
+check: fmt-check lint
+
+# Format code
+fmt: _ensure_tools
+    @uv run ruff format .
+
+# Check formatting without changing files
+fmt-check: _ensure_tools
+    @uv run ruff format --check .
+
+# Lint
+lint: _ensure_tools
+    @uv run ruff check .
diff --git a/pyproject.toml b/pyproject.toml
index 36f145c..f369248 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,6 +20,9 @@ dependencies = [
 meshcore = ["pycryptodome", "pynacl"]
 orac = ["pycryptodome", "pynacl", "anthropic"]
 
+[dependency-groups]
+dev = ["ruff"]
+
 [build-system]
 requires = ["hatchling"]
 build-backend = "hatchling.build"