diff --git a/docs/how-to/reject-client-connections.md b/docs/how-to/reject-client-connections.md new file mode 100644 index 00000000..5ca1d073 --- /dev/null +++ b/docs/how-to/reject-client-connections.md @@ -0,0 +1,56 @@ +# Rejecting Client Connections + +SpacetimeDB provides a way to disconnect a client during a client connection attempt. + +:::server-rust +In Rust, if we returned and error (or a panic) during the `client_connected` reducer, the client will be disconnected. + +Here is a simple example where the server module throws an error for all incoming client connections. +```rust +#[reducer(client_connected)] +pub fn client_connected(_ctx: &ReducerContext) -> Result<(), String> { + let client_is_rejected = true; + if client_is_rejected { + Err("The client connection was rejected. With our current code logic, all clients will be rejected.".to_string()) + } else { + Ok(()) + } +} +``` + +Client behavior can vary by client type. For example: +* **C# clients**: Client disconnection behavior is currently undefined and will generate an error reading: + `Unable to send subscribe message: WS sender loop has dropped its recv channel: TrySendError { kind: Disconnected }` + +* **Rust clients**: Client disconnection behavior is currently undefined and will generate an error reading: + `Unable to send subscribe message: WS sender loop has dropped its recv channel: TrySendError { kind: Disconnected }` + +* **TypeScript clients**: Client will receive an `Error connecting to SpacetimeDB:` and a `CloseEvent` with a code of 1006. + +Regardless of the client type, from the rust server's perspective, the client will be disconnected and the server module's logs will contain an entry reading: +`ERROR: : The client connection was rejected. With our current code logic, all clients will be rejected.` +::: +:::server-csharp +In C#, if we throw an exception during the `ClientConnected` reducer, the client will be disconnected. + +Here is a simple example where the server module throws an error for all incoming client connections. +```csharp +[Reducer(ReducerKind.ClientConnected)] +// Called when a client connects to a SpacetimeDB database server +public static void ClientConnected(ReducerContext ctx) +{ + throw new Exception("The client connection was rejected. With our current code logic, all clients will be rejected."); +} +``` + +Client behavior can vary by client type. For example: +* **C# clients**: Client disconnection behavior is currently undefined and will generate an error reading: +`Disconnected abnormally: System.Net.WebSockets.WebSocketException (0x80004005): The remote party closed the WebSocket connection without completing the close handshake.` + +* **Rust clients**: Client will receive an `on_disconnected` event with no error message. + +* **TypeScript clients**: Client will receive an `Error connecting to SpacetimeDB:` and a `CloseEvent` with a code of 1006. + +Regardless of the client type, from the C# server's perspective, the client will be disconnected and the server module's logs will contain an entry reading: +`ERROR: : System.Exception: The client connection was rejected. With our current code logic, all clients will be rejected.` +:::