MessageBody

MessageBody is a term used to describe the main payload or content portion of a message in computing and communications. It is distinct from metadata such as headers, routing information, and protocol controls.

In email, the message body is the content after the blank line that separates headers from the body; it may be plain text, HTML, or multipart with attachments. In HTTP, the body (often referred to as the message body) carries the request data or response payload, such as form data, JSON, XML, or binary files. In messaging systems and service buses, the messageBody contains the actual payload delivered to consumers, while accompanying properties provide metadata for routing, durability, or processing.

Formats and encoding vary by context. The body can be textual or binary, and a content-type header typically indicates how to interpret it. Binary data may be transmitted as base64 within text-based transports. Handling the body correctly often requires respecting content length or streaming the data to conserve memory.

Security and validity are important considerations. Processing a messageBody should include validation and sanitization to mitigate injection risks, proper handling of character encodings, and safeguards against oversized or malformed content.

In software development, APIs commonly expose the body as a string or byte array, with libraries offering utilities to parse, deserialize, or stream the body into structured representations (for example, JSON objects) depending on the content type. The concept is central across email, web, and messaging protocols.