prompt-model/ai.koog.prompt.message/MessagePart

MessagePart

A discrete piece of content within a Message. Parts are typed by their direction and purpose: RequestPart parts go to the LLM, ResponsePart parts come from the LLM, and ContentPart parts (text, attachments) are valid in both directions.

Inheritors

RequestPart

ResponsePart

Tool

Types

Attachment

@Serializable

data class Attachment @JvmOverloads constructor(val source: AttachmentSource, val cacheControl: CacheControl? = null) : MessagePart.ContentPart

Attachment content part of the message.

ContentPart

@Serializable

sealed interface ContentPart : MessagePart.RequestPart, MessagePart.ResponsePart

Represents a part of a message that can be used in both request and response contexts. Parts can be text MessagePart.Text or attachments MessagePart.Attachment.

Reasoning

@Serializable

data class Reasoning @JvmOverloads constructor(val content: List<String>, val summary: List<String>? = null, val encrypted: String? = null, val id: String? = null) : MessagePart.ResponsePart

Represents a reasoning message exchanged in a chat system, encapsulating the content, role, and associated metadata, with an optional reference to the original thinking process.

RequestPart

@Serializable

sealed interface RequestPart : MessagePart

A part that can appear in a request sent to the LLM. All request parts carry an optional cacheControl directive.

ResponsePart

@Serializable

sealed interface ResponsePart : MessagePart

A part that can appear in a response received from the LLM (e.g. text, reasoning, or tool calls).

Text

@Serializable

data class Text @JvmOverloads constructor(val text: String, val cacheControl: CacheControl? = null) : MessagePart.ContentPart

Text content part of the message.

Tool

@Serializable

sealed interface Tool : MessagePart

Represents messages exchanged with tools, either as calls or results.