updated caddyfile

Author: lisadunlap

Caddyfile

@@ -0,0 +1,62 @@
+# Caddyfile for StringSight API
+# Optimized for Vercel → Digital Ocean connections
+# Deploy this to your droplet at /etc/caddy/Caddyfile
+
+api.stringsight.com {
+    # Reverse proxy to your uvicorn backend
+    reverse_proxy localhost:8000 {
+        # Connection pooling - keeps connections alive
+        transport http {
+            keepalive 90s
+            keepalive_idle_conns 10
+        }
+
+        # Health check to verify backend is up
+        health_uri /health
+        health_interval 30s
+        health_timeout 5s
+    }
+
+    # CORS configuration for Vercel frontend
+    @cors_preflight {
+        method OPTIONS
+    }
+
+    # Handle CORS preflight quickly (this is KEY for performance!)
+    handle @cors_preflight {
+        header Access-Control-Allow-Origin "https://stringsight.vercel.app"
+        header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS"
+        header Access-Control-Allow-Headers "DNT, User-Agent, X-Requested-With, If-Modified-Since, Cache-Control, Content-Type, Range, Authorization"
+        header Access-Control-Max-Age "86400"  # Cache preflight for 24 hours
+        respond 204
+    }
+
+    # CORS headers for all responses
+    header Access-Control-Allow-Origin "https://stringsight.vercel.app"
+    header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS"
+    header Access-Control-Allow-Headers "DNT, User-Agent, X-Requested-With, If-Modified-Since, Cache-Control, Content-Type, Range, Authorization"
+    header Access-Control-Expose-Headers "Content-Length, Content-Range"
+    header Access-Control-Allow-Credentials "true"
+
+    # Increase request size limit for file uploads
+    request_body {
+        max_size 100MB
+    }
+
+    # Enable compression for API responses
+    encode gzip
+
+    # Logging
+    log {
+        output file /var/log/caddy/stringsight.log
+        format json
+        level INFO
+    }
+}
+
+# Optional: If you want to serve frontend from the same domain
+# www.stringsight.com, stringsight.com {
+#     root * /var/www/stringsight
+#     file_server
+#     try_files {path} /index.html
+# }

stringsight/database.py

@@ -34,6 +34,16 @@ def _create_engine(database_url: str) -> Engine:
             connect_args={"check_same_thread": False},
         )
 
+    # For PostgreSQL, use connection pooling to reduce cold start time
+    if database_url.startswith("postgresql://"):
+        return create_engine(
+            database_url,
+            pool_size=5,           # Keep 5 connections alive
+            max_overflow=10,       # Allow up to 10 additional connections during spikes
+            pool_pre_ping=True,    # Verify connections before use (prevents stale connections)
+            pool_recycle=3600,     # Recycle connections after 1 hour
+        )
+
     return create_engine(database_url)