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Vertex AI Agent Engine Sessions maintains the history of interactions between a user and agents. Sessions provide definitive sources for long-term memory and conversation context.
You have several options to use Vertex AI Agent Engine Sessions:
Agent Development Kit: Once you deploy your Agent Development Kit (ADK) agent to Vertex AI Agent Engine, session management is handled automatically.
API calls: You can make direct API calls to Vertex AI Agent Engine Sessions if you don't want to manage sessions using an ADK agent.
Core concepts
Session: A session represents the chronological sequence of messages and actions (events) for a single, ongoing interaction between a user and your agent system.
Event: An event stores the content of the conversation, as well as the actions taken by the agents such as function calls.
State: A state holds temporary data relevant only during the current conversation.
Memory: Memory is personalized information that can be accessed across multiple sessions for a particular user. The agent can use memories to personalize responses to the user and ensure cross-session continuity.
Core functionalities
The core functionalities of Vertex AI Agent Engine Sessions include the following:
Starting new conversations: Create new sessions when a user begins an interaction with an agent.
Resuming existing conversations: Retrieving a specific session so the agent can resume a conversation that has been paused.
Saving progress: Append new interactions (events) to a session's history to update the session.
Listing conversations: Find the active session threads for a particular user and application.
Cleaning up: Delete session objects and their associated data when conversations are finished or no longer needed.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-28 UTC."],[],[],null,["| **Preview**\n|\n|\n| This feature is subject to the \"Pre-GA Offerings Terms\" in the General Service Terms section\n| of the [Service Specific Terms](/terms/service-terms#1).\n|\n| Pre-GA features are available \"as is\" and might have limited support.\n|\n| For more information, see the\n| [launch stage descriptions](/products#product-launch-stages).\n\nVertex AI Agent Engine Sessions maintains the history of interactions between a user and agents. Sessions provide definitive sources for long-term memory and conversation context.\n\nYou have several options to use Vertex AI Agent Engine Sessions:\n\n- [Agent Development Kit](/vertex-ai/generative-ai/docs/agent-engine/sessions/manage-sessions-adk): Once you deploy your Agent Development Kit (ADK) agent to Vertex AI Agent Engine, session management is handled automatically.\n\n- [API calls](/vertex-ai/generative-ai/docs/agent-engine/sessions/manage-sessions-api): You can make direct API calls to Vertex AI Agent Engine Sessions if you don't want to manage sessions using an ADK agent.\n\nCore concepts\n\n- **Session**: A session represents the chronological sequence of messages and actions (events) for a single, ongoing interaction between a user and your agent system.\n\n- **Event**: An event stores the content of the conversation, as well as the actions taken by the agents such as function calls.\n\n- **State**: A state holds temporary data relevant only during the current conversation.\n\n- **Memory**: Memory is personalized information that can be accessed across multiple sessions for a particular user. The agent can use memories to personalize responses to the user and ensure cross-session continuity.\n\nCore functionalities\n\nThe core functionalities of Vertex AI Agent Engine Sessions include the following:\n\n- **Starting new conversations**: Create new sessions when a user begins an interaction with an agent.\n\n- **Resuming existing conversations**: Retrieving a specific session so the agent can resume a conversation that has been paused.\n\n- **Saving progress**: Append new interactions (events) to a session's history to update the session.\n\n- **Listing conversations**: Find the active session threads for a particular user and application.\n\n- **Cleaning up**: Delete session objects and their associated data when conversations are finished or no longer needed.\n\nWhat's next\n\n- [Manage sessions using ADK](/vertex-ai/generative-ai/docs/agent-engine/sessions/manage-sessions-adk).\n- [Manage sessions using API calls](/vertex-ai/generative-ai/docs/agent-engine/sessions/manage-sessions-api)."]]