# Key/Value Format

Kafka messages **MAY** include a key, which needs to be properly designed to have a good balance of data across partitions.

The message key and the payload (often called value) can be serialized independently and can have different formats. For example, the value of the message can be sent in AVRO format, while the message key can be a primitive type (string).

Message keys **SHOULD** be kept as simple as possible and use a primitive type when possible.


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://adidas.gitbook.io/api-guidelines/asynchronous-api-guidelines/kafka-asynchronous-guidelines/g_key_value_format.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.