google-adk-kotlin-core/com.google.adk.kt.events/Event

Event

data class Event(val id: String = Uuid.random(), val invocationId: String? = null, val author: String = "", val content: Content? = null, val actions: EventActions = EventActions(), val longRunningToolIds: Set<String> = emptySet(), val partial: Boolean = false, val turnComplete: Boolean = false, val errorCode: String? = null, val errorMessage: String? = null, val finishReason: FinishReason? = null, val usageMetadata: UsageMetadata? = null, val avgLogProbs: Double? = null, val interrupted: Boolean = false, val branch: String? = null, val groundingMetadata: GroundingMetadata? = null, val modelVersion: String? = null, val citationMetadata: CitationMetadata? = null, val cacheMetadata: CacheMetadata? = null, val customMetadata: Map<String, Any?>? = null, val output: Any? = null, val nodeInfo: NodeInfo? = null, val timestamp: Long = Clock.System.now().toEpochMilliseconds())

Represents an event in a session.

Constructors

Event

constructor(id: String = Uuid.random(), invocationId: String? = null, author: String = "", content: Content? = null, actions: EventActions = EventActions(), longRunningToolIds: Set<String> = emptySet(), partial: Boolean = false, turnComplete: Boolean = false, errorCode: String? = null, errorMessage: String? = null, finishReason: FinishReason? = null, usageMetadata: UsageMetadata? = null, avgLogProbs: Double? = null, interrupted: Boolean = false, branch: String? = null, groundingMetadata: GroundingMetadata? = null, modelVersion: String? = null, citationMetadata: CitationMetadata? = null, cacheMetadata: CacheMetadata? = null, customMetadata: Map<String, Any?>? = null, output: Any? = null, nodeInfo: NodeInfo? = null, timestamp: Long = Clock.System.now().toEpochMilliseconds())

Types

Builder

class Builder

Fluent builder for Event, provided primarily for Java callers. Any property left unset falls back to the same default as the constructor.

Companion

object Companion

Properties

actions

val actions: EventActions

Optional actions associated with this event.

author

@EncodeDefault(mode = EncodeDefault.Mode.ALWAYS)

val author: String

The author of the event, such as the name of the agent or node or "user"; defaults to "" and is stamped with the workflow or node name when emitted from a workflow node.

avgLogProbs

@SerialName(value = "avgLogprobs")

val avgLogProbs: Double?

The average log probabilities of the generated tokens.

branch

val branch: String?

The branch of the event. The format is like agent_1.agent_2.agent_3, where agent_1 is the parent of agent_2, and agent_2 is the parent of agent_3. Branch is used when multiple sub-agents shouldn't see their peer agents' conversation history.

cacheMetadata

val cacheMetadata: CacheMetadata?

Context cache metadata associated with this event's LLM response, used to carry cache state across turns. null when context caching is disabled.

citationMetadata

val citationMetadata: CitationMetadata?

content

val content: Content?

The content of the event.

customMetadata

val customMetadata: Map<String, Any?>?

errorCode

val errorCode: String?

An error code if an error occurred during the event processing.

errorMessage

val errorMessage: String?

A human-readable error message if an error occurred.

finishReason

val finishReason: FinishReason?

The reason the LLM generation finished.

groundingMetadata

val groundingMetadata: GroundingMetadata?

The grounding metadata of the event.

@EncodeDefault(mode = EncodeDefault.Mode.ALWAYS)

val id: String

The event id.

interrupted

val interrupted: Boolean

True if the generation of this event was interrupted.

invocationId

val invocationId: String?

Id of the invocation that this event belongs to.

isFinalResponse

val isFinalResponse: Boolean

Returns true if this event is the final response of an agent turn — i.e. it terminates the per-turn model loop in com.google.adk.kt.agents.LlmAgent.executeTurns. Matches ADK Python's Event.is_final_response(): skipSummarization or a non-empty longRunningToolIds set both mark the event as final, otherwise the event is final iff it carries no function calls, no function responses, is not a partial streaming chunk, and has no trailing code-execution-result part.

longRunningToolIds

val longRunningToolIds: Set<String>

Set of ids of the long running function calls. Agent client will know from this field about which function call is long running.

modelVersion

val modelVersion: String?

The model version used to generate the response.

nodeInfo

@Serializable(with = NodeInfoNullIfEmptySerializer::class)

val nodeInfo: NodeInfo?

Identifies the workflow-node activation that emitted this event; null outside a workflow.

output

val output: Any?

For a workflow node, the value handed to successors, distinct from content.

partial

val partial: Boolean

True for incomplete chunks from the LLM streaming response. The last chunk's partial is false.

timestamp

@EncodeDefault(mode = EncodeDefault.Mode.ALWAYS)

@Serializable(with = LenientEpochMillisSerializer::class)

val timestamp: Long

The timestamp of the event.

turnComplete

val turnComplete: Boolean

True if this event marks the completion of a turn.

usageMetadata

val usageMetadata: UsageMetadata?

Metadata about the token usage for the LLM call.

Functions

contentText

@JvmOverloads

fun contentText(separator: CharSequence = "", includeThoughts: Boolean = false): String

Returns this event's content text joined with separator (none by default), or "" when the event has no content; forwards includeThoughts to Content.text.

functionCalls

fun functionCalls(): List<FunctionCall>

Returns all function calls from this event.

functionResponses

fun functionResponses(): List<FunctionResponse>

Returns all function responses from this event.

hasTrailingCodeExecutionResult

fun hasTrailingCodeExecutionResult(): Boolean

Returns true if the last part of this event is a code-execution result. Mirrors ADK Java's Event.hasTrailingCodeExecutionResult(), keeping such an event out of isFinalResponse so the turn loop runs again to let the model act on the result.

populateClientFunctionCallId

fun populateClientFunctionCallId(): Event

Scans a model response event's parts for function calls missing an ID and generates one for them.

toBuilder

fun toBuilder(): Event.Builder

Returns a Builder initialized with this instance's properties, primarily for Java callers. Prefer it over copy from Java: copy takes every property positionally, so its signature changes whenever a property is added.