diff --git a/src/Dragon-ISO.Engine/Interop/INdiInterop.cs b/src/Dragon-ISO.Engine/Interop/INdiInterop.cs
index 4778c63..f68b5f7 100644
--- a/src/Dragon-ISO.Engine/Interop/INdiInterop.cs
+++ b/src/Dragon-ISO.Engine/Interop/INdiInterop.cs
@@ -47,14 +47,22 @@ public interface INdiInterop
// ----- Send -----
///
- /// Creates an NDI sender broadcasting on the given groups.
+ /// Creates an NDI sender broadcasting on the given groups at the given frame rate.
///
/// The NDI source name segment (the part inside parens).
///
/// Comma-separated list of NDI group names to broadcast on. null or empty
/// uses the NDI default ("Public").
///
- NdiSenderHandle CreateSender(string outputName, string? groups = null);
+ ///
+ /// Frame-rate numerator advertised on every frame the sender emits (the NDI
+ /// frame_rate_N). Defaults to 60000 (the numerator of 59.94).
+ ///
+ ///
+ /// Frame-rate denominator (the NDI frame_rate_D). Defaults to 1001, so the
+ /// default pair 60000/1001 is exactly 59.94 fps. Must be positive.
+ ///
+ NdiSenderHandle CreateSender(string outputName, string? groups = null, int frameRateN = 60000, int frameRateD = 1001);
void SendFrame(NdiSenderHandle sender, ProcessedFrame frame);