No free plan. The cheapest way in is Pay-as-you-go at Contact for pricing. Consider free alternatives in the agent category if budget is tight.
ADK is an open-source framework for building agents in code. Vertex AI Agent Builder is a managed cloud platform that can use ADK-built agents or provide no-code agent creation with managed hosting.
Vertex AI Agent Builder primarily uses Gemini models. For other models, you'd use Vertex AI's Model Garden or bring custom models, but the agent builder is optimized for Gemini.
You connect data sources (documents, websites, databases) and the platform automatically chunks, embeds, and indexes content. Agents retrieve relevant context before generating responses.
Dialogflow CX is for structured conversational flows. Agent Builder adds generative AI capabilities, enterprise search, and flexible agent types beyond traditional chatbots.
See Google Vertex AI Agent Builder plans and find the right tier for your needs.
See Pricing Plans →Still not sure? Read our full verdict →
Last verified March 2026