reflex-process-management

# Reflex Process Management This skill covers how to compile, run, and reload a Reflex application. ## Compiling (Testing the App) To verify the app compiles without errors, run: ```bash reflex compile --dry ``` This checks for syntax errors, import issues, and component problems without starting the server. Use this as a quick validation step after making changes. ## Running the Server When instructed to run the Reflex server, always use production mode and redirect output to a log file: ```bash reflex run --env prod --single-port 2>&1 | tee reflex.log ``` This command starts a long-running server process that **does not support hot reload** in production mode. Code changes will not be picked up automatically — you must stop and restart the server to apply changes (see **Reloading a Running App** below). Using `2>&1 | tee reflex.log` captures both stdout and stderr to `reflex.log` while still printing to the terminal. > **Important:** Always use `--env prod` unless the user explicitly requests development mode. ## Reloading a Running App To reload the app without manually stopping and restarting from the terminal, follow these steps: ### Step 1: Determine the app port Read `reflex.log` to find the port the app is listening on. Look for a line like `App running at: http://0.0.0.0:<port>`. Do not assume the port is 8000. ### Step 2: Find the app process Using the port from Step 1, locate the **listening** process (not browser connections): ```bash lsof -i :<port> -sTCP:LISTEN -t ``` The `-sTCP:LISTEN` flag is critical — it filters to only the server process that is _listening_ on the port, excluding browser or client connections. Without it, you may kill the user's browser. If `lsof` is not available, use: ```bash ss -tlnp | grep :<port> ``` Or: ```bash fuser <port>/tcp ``` ### Step 3: Send an interrupt signal Send `SIGINT` (equivalent to Ctrl+C) to gracefully stop the process: ```bash kill -INT $(lsof -i :<port> -sTCP:LISTEN -t) ``` If the process doesn't stop, escalate to `SIGTERM`: ```bash kill -TERM $(lsof -i :<port> -sTCP:LISTEN -t) ``` ### Step 4: Restart the server Once the old process has exited, truncate the old log and start the server again: ```bash > reflex.log reflex run --env prod --single-port 2>&1 | tee reflex.log ``` ## Investigating Errors When the user reports an error, read `reflex.log` to find and diagnose the issue.