diff --git a/.env.example b/.env.example
index a258247..6bf0379 100644
--- a/.env.example
+++ b/.env.example
@@ -6,8 +6,7 @@ ARTDAG_DOMAIN=artdag.rose-ash.com
 # Default username (for actor endpoints)
 ARTDAG_USER=giles
 
-# L1 server URL (for fetching run data)
-ARTDAG_L1=https://l1.artdag.rose-ash.com
-
 # JWT secret for token signing (generate with: openssl rand -hex 32)
 JWT_SECRET=your-secret-here-generate-with-openssl-rand-hex-32
+
+# Note: ARTDAG_L1 is no longer needed - L1 server URL is sent with each request
diff --git a/docker-stack.yml b/docker-stack.yml
index ead4f0c..a5a499e 100644
--- a/docker-stack.yml
+++ b/docker-stack.yml
@@ -29,7 +29,7 @@ services:
     environment:
       - REDIS_URL=redis://redis:6379/5
       - CACHE_DIR=/data/cache
-      # L2_SERVER and L2_DOMAIN from .env file
+      # L1_PUBLIC_URL, L2_SERVER, L2_DOMAIN from .env file
     volumes:
       - l1_cache:/data/cache
     depends_on:
@@ -69,7 +69,7 @@ services:
       - .env
     environment:
       - ARTDAG_DATA=/data/l2
-      # ARTDAG_DOMAIN, ARTDAG_USER, ARTDAG_L1, JWT_SECRET from .env file
+      # ARTDAG_DOMAIN, ARTDAG_USER, JWT_SECRET from .env file
     volumes:
       - l2_data:/data/l2
     depends_on:
diff --git a/server.py b/server.py
index 97ca832..9fa98b3 100644
--- a/server.py
+++ b/server.py
@@ -93,6 +93,7 @@ class RecordRunRequest(BaseModel):
     """Request to record an L1 run."""
     run_id: str
     output_name: str
+    l1_server: str  # URL of the L1 server that has this run
 
 
 class PublishCacheRequest(BaseModel):
@@ -1034,13 +1035,14 @@ async def register_asset(req: RegisterRequest, user: User = Depends(get_required
 @app.post("/registry/record-run")
 async def record_run(req: RecordRunRequest, user: User = Depends(get_required_user)):
     """Record an L1 run and register the output. Requires authentication."""
-    # Fetch run from L1 server
+    # Fetch run from the specified L1 server
+    l1_url = req.l1_server.rstrip('/')
     try:
-        resp = requests.get(f"{L1_SERVER}/runs/{req.run_id}")
+        resp = requests.get(f"{l1_url}/runs/{req.run_id}")
         resp.raise_for_status()
         run = resp.json()
     except Exception as e:
-        raise HTTPException(400, f"Failed to fetch run from L1: {e}")
+        raise HTTPException(400, f"Failed to fetch run from L1 ({l1_url}): {e}")
 
     if run.get("status") != "completed":
         raise HTTPException(400, f"Run not completed: {run.get('status')}")
@@ -1053,6 +1055,7 @@ async def record_run(req: RecordRunRequest, user: User = Depends(get_required_us
     provenance = {
         "inputs": [{"content_hash": h} for h in run.get("inputs", [])],
         "recipe": run.get("recipe"),
+        "l1_server": l1_url,
         "l1_run_id": req.run_id,
         "rendered_at": run.get("completed_at")
     }
@@ -1063,7 +1066,7 @@ async def record_run(req: RecordRunRequest, user: User = Depends(get_required_us
         content_hash=output_hash,
         asset_type="video",  # Could be smarter about this
         tags=["rendered", "l1"],
-        metadata={"l1_run_id": req.run_id},
+        metadata={"l1_server": l1_url, "l1_run_id": req.run_id},
         provenance=provenance
     ), user.username)