google-adk-kotlin-core/com.google.adk.kt.sessions/VertexAiSessionService

VertexAiSessionService

class VertexAiSessionService : SessionService

A SessionService backed by the managed Vertex AI Session Service.

This is a Kotlin port of the Java ADK com.google.adk.sessions.VertexAiSessionService. It talks to the service through a VertexAiSessionsClient over a shared GoogleApiClient. The wire format (defined by session.proto) is modeled with a small set of @Serializable DTOs in the dto sub-package; this class only translates between those DTOs and the ADK domain types via the mapper extensions in com.google.adk.kt.sessions.dto.SessionMappers.

The reasoning engine is fixed at construction from project, location, and reasoningEngineId. Unlike the Python and Java ADK, the session key's SessionKey.appName is never parsed to derive the engine - it is only a label - so the engine must be supplied explicitly here.

Constructors

VertexAiSessionService

constructor(project: String, location: String, reasoningEngineId: String, credentials: GoogleCredentials = GoogleApiClient.defaultCredentials(), httpClient: HttpClient = HttpClient(Java), sessionTtl: Duration? = null)

Creates a service for reasoning engine reasoningEngineId under project and location.

Types

Builder

class Builder

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

Companion

object Companion

Functions

appendEvent

open suspend override fun appendEvent(session: Session, event: Event): Event

Appends event to session, applying its state delta to the in-memory session and recording the event; temp: keys are applied to the in-memory state (so later agents in the invocation can read them) but removed from event before persistence.

closeSession

open suspend fun closeSession(session: Session)

Closes a session.

createSession

open suspend override fun createSession(key: SessionKey, state: Map<String, Any>? = null): Session

Creates a new session with the specified parameters.

suspend fun createSession(key: SessionKey, state: Map<String, Any>? = null, ttl: Duration? = null, expireTime: Instant? = null): Session

Creates a session that expires, addressing the reasoning engine fixed at construction.

deleteSession

open suspend override fun deleteSession(key: SessionKey)

Deletes a specific session.

getSession

open suspend override fun getSession(key: SessionKey, config: GetSessionConfig? = null): Session?

Retrieves a specific session, optionally filtering the events included.

listEvents

open suspend override fun listEvents(key: SessionKey): ListEventsResponse

Lists the events within a specific session.

listSessions

open suspend override fun listSessions(appName: String, userId: String): ListSessionsResponse

Lists sessions associated with a specific application and user.