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> For a complete documentation index, see https://docs.nvidia.com/holoscan/sdk-user-guide/llms.txt.
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# holoscan::annotate_message

> This function annotates a message with a MessageLabel timestamp.

```cpp showLineNumbers={false}
gxf_result_t holoscan::annotate_message(
    gxf_uid_t uid,
    const gxf_context_t &context,
    Operator *op,
    const char *transmitter_name
)
```

This function annotates a message with a [MessageLabel](../classes/messagelabel) timestamp.

**Returns:** gxf\_result\_t The result of the annotation.

**Parameters**

The entity ID of the message.

The GXF context.

The operator that is transmitting the message.

The name of the transmitter from which the message is being published.