diff --git a/README.md b/README.md
index fee4b86..8096e7b 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,7 @@ cd notes-rag
 pip install -e ".[dev]"
 pytest
 python -m notes_rag --mock "What is a git remote?"
+# add --json for machine-readable answer and sources
 ```
 
 You should see a `[mock]` answer plus a **Sources** list. That means retrieval works before you spend a token.
diff --git a/src/notes_rag/cli.py b/src/notes_rag/cli.py
index c0d1c34..6f043a0 100644
--- a/src/notes_rag/cli.py
+++ b/src/notes_rag/cli.py
@@ -3,6 +3,7 @@
 from __future__ import annotations
 
 import argparse
+import json
 import sys
 from pathlib import Path
 
@@ -34,6 +35,11 @@ def build_parser() -> argparse.ArgumentParser:
         action="store_true",
         help="Answer from retrieved notes without calling an API",
     )
+    p.add_argument(
+        "--json",
+        action="store_true",
+        help="Emit the answer and sources as JSON",
+    )
     return p
 
 
@@ -47,8 +53,26 @@ def main(argv: list[str] | None = None) -> int:
     hits = retrieve(notes, args.question, k=args.k)
     answerer = Answerer.from_env(mock=args.mock)
     try:
-        print(answerer.answer(args.question, hits))
-        if hits:
+        answer = answerer.answer(args.question, hits)
+        if args.json:
+            print(
+                json.dumps(
+                    {
+                        "answer": answer,
+                        "sources": [
+                            {
+                                "title": note.title,
+                                "file": note.path.name,
+                                "score": score,
+                            }
+                            for note, score in hits
+                        ],
+                    }
+                )
+            )
+        else:
+            print(answer)
+        if hits and not args.json:
             print("\nSources:")
             for note, score in hits:
                 print(f"  - {note.title} ({note.path.name}, score={score:.3f})")
diff --git a/tests/test_notes_rag.py b/tests/test_notes_rag.py
index 925a97d..7a210de 100644
--- a/tests/test_notes_rag.py
+++ b/tests/test_notes_rag.py
@@ -1,3 +1,4 @@
+import json
 from pathlib import Path
 
 from notes_rag.answer import Answerer
@@ -37,6 +38,15 @@ def test_mock_answer_cites(capsys):
     assert "Sources:" in out
 
 
+def test_mock_json_output(capsys):
+    code = main(["--mock", "--json", "--notes", str(NOTES), "What is a git remote?"])
+    out = capsys.readouterr().out
+    assert code == 0
+    result = json.loads(out)
+    assert result["answer"].startswith("[mock]")
+    assert result["sources"]
+
+
 def test_empty_notes_dir(tmp_path, capsys):
     empty = tmp_path / "empty"
     empty.mkdir()