diff --git a/decnet/env.py b/decnet/env.py
index 3b30f9b..f247352 100644
--- a/decnet/env.py
+++ b/decnet/env.py
@@ -53,6 +53,12 @@ def _require_env(name: str) -> str:
 # System logging — all microservice daemons append here.
 DECNET_SYSTEM_LOGS: str = os.environ.get("DECNET_SYSTEM_LOGS", "decnet.system.log")
 
+# Set to "true" to embed the profiler inside the API process.
+# Leave unset (default) when the standalone `decnet profiler --daemon` is
+# running — embedding both produces two workers sharing the same DB cursor,
+# which causes events to be skipped or processed twice.
+DECNET_EMBED_PROFILER: bool = os.environ.get("DECNET_EMBED_PROFILER", "").lower() == "true"
+
 # API Options
 DECNET_API_HOST: str = os.environ.get("DECNET_API_HOST", "0.0.0.0")  # nosec B104
 DECNET_API_PORT: int = _port("DECNET_API_PORT", 8000)
diff --git a/decnet/web/api.py b/decnet/web/api.py
index 8d044f5..aac1249 100644
--- a/decnet/web/api.py
+++ b/decnet/web/api.py
@@ -9,7 +9,7 @@ from fastapi.responses import JSONResponse
 from pydantic import ValidationError
 from fastapi.middleware.cors import CORSMiddleware
 
-from decnet.env import DECNET_CORS_ORIGINS, DECNET_DEVELOPER, DECNET_INGEST_LOG_FILE
+from decnet.env import DECNET_CORS_ORIGINS, DECNET_DEVELOPER, DECNET_EMBED_PROFILER, DECNET_INGEST_LOG_FILE
 from decnet.logging import get_logger
 from decnet.web.dependencies import repo
 from decnet.collector import log_collector_worker
@@ -65,10 +65,16 @@ async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
         elif not _log_file:
             log.warning("DECNET_INGEST_LOG_FILE not set — Docker log collection disabled.")
 
-        # Start attacker profile rebuild worker
-        if attacker_task is None or attacker_task.done():
-            attacker_task = asyncio.create_task(attacker_profile_worker(repo))
-            log.debug("API startup attacker profile worker started")
+        # Start attacker profile rebuild worker only when explicitly requested.
+        # Default is OFF because `decnet deploy` always starts a standalone
+        # `decnet profiler --daemon` process.  Running both against the same
+        # DB cursor causes events to be skipped or double-processed.
+        if DECNET_EMBED_PROFILER:
+            if attacker_task is None or attacker_task.done():
+                attacker_task = asyncio.create_task(attacker_profile_worker(repo))
+                log.info("API startup: embedded profiler started (DECNET_EMBED_PROFILER=true)")
+        else:
+            log.debug("API startup: profiler not embedded — expecting standalone daemon")
 
         # Start fleet-wide MACVLAN sniffer (fault-isolated — never crashes the API)
         try: