ai-elements-chat/dev.ai.elements.core.chat/ChatEvent

ChatEvent

Protocol-neutral stream events. They map 1:1 onto the AI SDK UI Message Stream chunk types, so every backend (UI Message Stream, OpenAI, Anthropic, mock) translates its wire format into the same small vocabulary.

Inheritors

Types

Data

data class Data(val id: String, val name: String, val data: JsonElement) : ChatEvent

An AI SDK data-* part; same id replaces.

Error

data class Error(val message: String) : ChatEvent

An in-band error reported by the server.

File

data class File(val id: String, val mediaType: String, val url: String) : ChatEvent

A model-generated file (e.g. an image).

Finish

data object Finish : ChatEvent

Explicit end of the turn. Optional: a completed flow also ends the turn.

Metadata

data class Metadata(val metadata: JsonObject) : ChatEvent

Merged into Message.metadata (AI SDK message-metadata).

ReasoningDelta

data class ReasoningDelta(val id: String, val delta: String) : ChatEvent

ReasoningEnd

data class ReasoningEnd(val id: String) : ChatEvent

SourceUrl

data class SourceUrl(val id: String, val url: String, val title: String) : ChatEvent

SubagentUpdate

data class SubagentUpdate(val id: String, val message: Message) : ChatEvent

Snapshot of a delegated agent's run inside tool call id (populated by the backend).

TextDelta

data class TextDelta(val id: String, val delta: String) : ChatEvent

TextEnd

data class TextEnd(val id: String) : ChatEvent

ToolApprovalRequest

data class ToolApprovalRequest(val id: String, val answers: ApprovalAnswers = dev.ai.elements.core.model.ApprovalAnswers.All) : ChatEvent

The backend is waiting for ToolApprover to approve this tool call; answers says what its protocol can carry back beyond yes / no.

ToolApproved

data class ToolApproved(val id: String) : ChatEvent

The user approved; the tool runs (or the server continues) next.

ToolDenied

data class ToolDenied(val id: String, val reason: String? = null) : ChatEvent

The user denied the call, optionally saying why.

ToolError

data class ToolError(val id: String, val error: String) : ChatEvent

ToolInputAvailable

data class ToolInputAvailable(val id: String, val name: String, val input: String, val title: String? = null, val kind: ToolKind? = null, val source: String? = null, val category: ToolCategory? = null, val location: String? = null) : ChatEvent

ToolInputDelta

data class ToolInputDelta(val id: String, val delta: String) : ChatEvent

ToolInputStart

data class ToolInputStart(val id: String, val name: String, val title: String? = null) : ChatEvent

ToolOutput

data class ToolOutput(val id: String, val output: String, val preliminary: Boolean = false) : ChatEvent

A tool result; preliminary results are replaced by later ones (AI SDK preliminary tool results).

Usage

data class Usage(val inputTokens: Int, val outputTokens: Int) : ChatEvent

Token usage of one model call; summed per turn.