diff --git a/src/cli.py b/src/cli.py
new file mode 100644
index 0000000..1999093
--- /dev/null
+++ b/src/cli.py
@@ -0,0 +1,37 @@
+"""Command‑line interface for the research brief generator.
+
+Usage:
+    python -m src.cli "Your research question"
+
+The CLI will:
+1. Build the LangGraph.
+2. Run the graph with the supplied topic.
+3. Print the outline, step‑by‑step notes, and final brief.
+"""
+
+import asyncio
+import sys
+from .brief import build_graph
+
+def main():
+    if len(sys.argv) < 2:
+        print("Usage: python -m src.cli \"Your research question\"")
+        sys.exit(1)
+    topic = sys.argv[1]
+    graph = build_graph()
+    state = {
+        "topic": topic,
+        "outline": None,
+        "step_index": 0,
+        "notes": [],
+        "final_brief": None,
+    }
+    result = asyncio.run(graph.invoke(state))
+    # The graph already prints progress.
+    # Print final brief if not already printed.
+    if result.get("final_brief"):
+        print("\n=== Final Brief ===")
+        print(result["final_brief"])
+
+if __name__ == "__main__":
+    main()
\ No newline at end of file