diff --git a/backend/services/regulars_v2.py b/backend/services/regulars_v2.py
index addc98b..1e13303 100644
--- a/backend/services/regulars_v2.py
+++ b/backend/services/regulars_v2.py
@@ -1,4 +1,5 @@
 from dataclasses import dataclass
+from datetime import date
 from pathlib import Path
 import json
 import re
@@ -103,3 +104,33 @@ async def _call_sonnet(prompt: str) -> dict:
 async def evaluate_promotion(caller_name: str, call_transcript: str) -> dict:
     prompt = PROMOTION_PROMPT.format(name=caller_name, transcript=call_transcript)
     return await _call_sonnet(prompt)
+
+
+def write_new_regular(name: str, voice: str, age: int, identity_paragraph: str,
+                      arc_plan: str, first_call_summary: str) -> Path:
+    REGULARS_DIR.mkdir(parents=True, exist_ok=True)
+    slug = name.lower().replace(" ", "-")
+    path = REGULARS_DIR / f"{slug}.md"
+    today = date.today().isoformat()
+    content = f"""---
+name: {name}
+voice: {voice}
+age: {age}
+arc_state: {arc_plan}
+promoted_on: {today}
+---
+
+# {name}
+
+{identity_paragraph}
+
+## Arc Plan
+
+{arc_plan}
+
+## Arc Log
+
+- {today}: {first_call_summary}
+"""
+    path.write_text(content)
+    return path
diff --git a/tests/test_regulars_v2.py b/tests/test_regulars_v2.py
index affb24d..79d3026 100644
--- a/tests/test_regulars_v2.py
+++ b/tests/test_regulars_v2.py
@@ -69,3 +69,24 @@ def test_call_sonnet_strips_markdown_fences():
         result = asyncio.run(_call_sonnet("prompt"))
     assert result["promote"] is True
     assert result["arc_plan"] == "ok"
+
+
+def test_write_new_regular_creates_lore_file(tmp_path, monkeypatch):
+    monkeypatch.setattr("backend.services.regulars_v2.REGULARS_DIR", tmp_path)
+    from backend.services.regulars_v2 import write_new_regular
+
+    write_new_regular(
+        name="Bobby",
+        voice="Marcus",
+        age=34,
+        identity_paragraph="A landscaper in Las Cruces who...",
+        arc_plan="3 episodes: distant → reveal → apology",
+        first_call_summary="Called about damaged car",
+    )
+    f = tmp_path / "bobby.md"
+    assert f.exists()
+    body = f.read_text()
+    assert "name: Bobby" in body
+    assert "voice: Marcus" in body
+    assert "A landscaper in Las Cruces" in body
+    assert "3 episodes: distant → reveal → apology" in body