diff --git a/src/config.py b/src/config.py
index b959a4e8..efb53c42 100644
--- a/src/config.py
+++ b/src/config.py
@@ -149,6 +149,12 @@ class Settings(BaseSettings):
         "http://127.0.0.1:8000",
     ]
 
+    # ── Matrix Frontend Integration ────────────────────────────────────────
+    # URL of the Matrix frontend (Replit/Tailscale) for CORS.
+    # When set, this origin is added to CORS allowed_origins.
+    # Example: "http://100.124.176.28:8080" or "https://alexanderwhitestone.com"
+    matrix_frontend_url: str = ""  # Empty = disabled
+
     # Trusted hosts for the Host header check (TrustedHostMiddleware).
     # Set TRUSTED_HOSTS as a comma-separated list. Wildcards supported (e.g. "*.ts.net").
     # Defaults include localhost + Tailscale MagicDNS. Add your Tailscale IP if needed.
diff --git a/src/dashboard/app.py b/src/dashboard/app.py
index 868a5b61..3bf6ac3f 100644
--- a/src/dashboard/app.py
+++ b/src/dashboard/app.py
@@ -10,6 +10,7 @@ Key improvements:
 import asyncio
 import json
 import logging
+import re
 from contextlib import asynccontextmanager
 from pathlib import Path
 
@@ -520,17 +521,40 @@ app = FastAPI(
 
 
 def _get_cors_origins() -> list[str]:
-    """Get CORS origins from settings, rejecting wildcards in production."""
-    origins = settings.cors_origins
+    """Get CORS origins from settings, rejecting wildcards in production.
+
+    Adds matrix_frontend_url when configured. Always allows Tailscale IPs
+    (100.x.x.x range) for development convenience.
+    """
+    origins = list(settings.cors_origins)
+
+    # Strip wildcards in production (security)
     if "*" in origins and not settings.debug:
         logger.warning(
             "Wildcard '*' in CORS_ORIGINS stripped in production — "
             "set explicit origins via CORS_ORIGINS env var"
         )
         origins = [o for o in origins if o != "*"]
+
+    # Add Matrix frontend URL if configured
+    if settings.matrix_frontend_url:
+        url = settings.matrix_frontend_url.strip()
+        if url and url not in origins:
+            origins.append(url)
+            logger.debug("Added Matrix frontend to CORS: %s", url)
+
     return origins
 
 
+# Pattern to match Tailscale IPs (100.x.x.x) for CORS origin regex
+_TAILSCALE_IP_PATTERN = re.compile(r"^https?://100\.\d{1,3}\.\d{1,3}\.\d{1,3}(?::\d+)?$")
+
+
+def _is_tailscale_origin(origin: str) -> bool:
+    """Check if origin is a Tailscale IP (100.x.x.x range)."""
+    return bool(_TAILSCALE_IP_PATTERN.match(origin))
+
+
 # Add dedicated middleware in correct order
 # 1. Logging (outermost to capture everything)
 app.add_middleware(RequestLoggingMiddleware, skip_paths=["/health"])
@@ -552,6 +576,7 @@ app.add_middleware(
 app.add_middleware(
     CORSMiddleware,
     allow_origins=_get_cors_origins(),
+    allow_origin_regex=r"https?://100\.\d{1,3}\.\d{1,3}\.\d{1,3}(:\d+)?",
     allow_credentials=True,
     allow_methods=["GET", "POST", "PUT", "DELETE", "OPTIONS"],
     allow_headers=["Content-Type", "Authorization"],