> This page is for version 4.3.
> For other versions, use one of these documentation indexes:
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> - 4.5: https://docs.nvidia.com/holoscan/sdk-user-guide/4-5/llms.txt
> - 4.4: https://docs.nvidia.com/holoscan/sdk-user-guide/4-4/llms.txt
> - 4.3: https://docs.nvidia.com/holoscan/sdk-user-guide/4-3/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**

**`uid`** `gxf_uid_t`

The entity ID of the message.

---

**`context`** `const gxf_context_t &`

The GXF context.

---

**`op`** `Operator *`

The operator that is transmitting the message.

---

**`transmitter_name`** `const char *`

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

---