Vertex AI Agent Builder

Description

Vertex AI Agent Builder (now branded Gemini Enterprise Agent Platform) is Google Cloud's open platform for building, scaling, and governing agents. The build pillar is the Agent Development Kit (ADK) — an open-source framework in Python, Java, Go, and TypeScript that supports both code-defined custom agents and pre-built workflow agents (SequentialAgent, ParallelAgent, LoopAgent), with native multi-agent composition (sub-agents, hierarchical delegation), tools (built-in, custom, MCP, OpenAPI), and the A2A protocol for agent-to-agent communication. The scale pillar is Vertex AI Agent Engine: a managed runtime with Sessions (conversation state), Memory Bank (long-term personalised memory), and Code Execution. Agent Garden ships curated samples for one-click deployment. Governance layers add Cloud Trace observability, IAM-based agent identity, and Security Command Center threat detection.

Solution

Two-tier shape. ADK defines the agent loop: an LlmAgent reasons over instructions and decides which tool or sub-agent to call, while workflow agents (SequentialAgent / ParallelAgent / LoopAgent) compose deterministic pipelines around LLM agents. Multi-agent hierarchies delegate by transferring control to sub-agents. The composed agent is then deployed onto Agent Engine, which provides the managed runtime, Sessions for conversation state, Memory Bank for persistent long-term memory, sandboxed Code Execution, and Cloud Trace observability. Tools span built-in, custom, OpenAPI, MCP, and A2A endpoints.

Primary use cases

• code-first multi-agent systems built with ADK and deployed on Agent Engine
• workflow agents (sequential / parallel / loop) for predictable pipelines
• long-running production agents with managed Sessions and Memory Bank
• RAG agents grounded by Vertex AI Search and Vertex AI RAG Engine
• agent-to-agent ecosystems over the open A2A protocol