Desenvolver e implantar agentes no Vertex AI Agent Engine

Esta página mostra como criar e implantar um agente que retorna a taxa de câmbio entre duas moedas em uma data especificada usando os seguintes frameworks de agente:

Antes de começar

  1. Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
  2. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Go to project selector

  3. Verify that billing is enabled for your Google Cloud project.

  4. Enable the Vertex AI and Cloud Storage APIs.

    Enable the APIs

  5. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Go to project selector

  6. Verify that billing is enabled for your Google Cloud project.

  7. Enable the Vertex AI and Cloud Storage APIs.

    Enable the APIs

  8. Para receber as permissões necessárias para usar o mecanismo de agente da Vertex AI, peça ao administrador para conceder a você os seguintes papéis do IAM no projeto:

    Para mais informações sobre a concessão de papéis, consulte Gerenciar o acesso a projetos, pastas e organizações.

    Também é possível conseguir as permissões necessárias usando papéis personalizados ou outros papéis predefinidos.

    Instalar e inicializar o SDK do Vertex AI para Python

    1. Execute o seguinte comando para instalar o SDK da Vertex AI para Python e outros pacotes necessários:

      ADK

      pip install --upgrade --quiet google-cloud-aiplatform[agent_engines,adk]

      LangGraph

      pip install --upgrade --quiet google-cloud-aiplatform[agent_engines,langchain]

      LangChain

      pip install --upgrade --quiet google-cloud-aiplatform[agent_engines,langchain]

      AG2

      pip install --upgrade --quiet google-cloud-aiplatform[agent_engines,ag2]

      LlamaIndex

      pip install --upgrade --quiet google-cloud-aiplatform[agent_engines,llama_index]
    2. Autenticar como usuário

      Colab

      Execute o seguinte código:

      from google.colab import auth
      
      auth.authenticate_user(project_id="PROJECT_ID")
      

      Cloud Shell

      Nenhuma ação é necessária.

      Shell local

      Execute este comando:

      gcloud auth application-default login
    3. Execute o código a seguir para importar o Vertex AI Agent Engine e inicializar o SDK:

      import vertexai
      from vertexai import agent_engines
      
      vertexai.init(
          project="PROJECT_ID",               # Your project ID.
          location="LOCATION",                # Your cloud region.
          staging_bucket="gs://BUCKET_NAME",  # Your staging bucket.
      )
      

    Desenvolver um agente

    Primeiro, desenvolva uma ferramenta:

    def get_exchange_rate(
        currency_from: str = "USD",
        currency_to: str = "EUR",
        currency_date: str = "latest",
    ):
        """Retrieves the exchange rate between two currencies on a specified date."""
        import requests
    
        response = requests.get(
            f"https://api.frankfurter.app/{currency_date}",
            params={"from": currency_from, "to": currency_to},
        )
        return response.json()
    

    Em seguida, instancie um agente:

    ADK

    from google.adk.agents import Agent
    from vertexai.preview.reasoning_engines import AdkApp
    
    agent = Agent(
        model="gemini-2.0-flash",
        name='currency_exchange_agent',
        tools=[get_exchange_rate],
    )
    
    app = AdkApp(agent=agent)
    

    LangGraph

    from vertexai import agent_engines
    
    agent = agent_engines.LanggraphAgent(
        model="gemini-2.0-flash",
        tools=[get_exchange_rate],
        model_kwargs={
            "temperature": 0.28,
            "max_output_tokens": 1000,
            "top_p": 0.95,
        },
    )
    

    LangChain

    from vertexai import agent_engines
    
    agent = agent_engines.LangchainAgent(
        model="gemini-2.0-flash",
        tools=[get_exchange_rate],
        model_kwargs={
            "temperature": 0.28,
            "max_output_tokens": 1000,
            "top_p": 0.95,
        },
    )
    

    AG2

    from vertexai import agent_engines
    
    agent = agent_engines.AG2Agent(
        model="gemini-2.0-flash",
        runnable_name="Get Exchange Rate Agent",
        tools=[get_exchange_rate],
    )
    

    LlamaIndex

    from vertexai.preview import reasoning_engines
    
    def runnable_with_tools_builder(model, runnable_kwargs=None, **kwargs):
        from llama_index.core.query_pipeline import QueryPipeline
        from llama_index.core.tools import FunctionTool
        from llama_index.core.agent import ReActAgent
    
        llama_index_tools = []
        for tool in runnable_kwargs.get("tools"):
            llama_index_tools.append(FunctionTool.from_defaults(tool))
        agent = ReActAgent.from_tools(llama_index_tools, llm=model, verbose=True)
        return QueryPipeline(modules = {"agent": agent})
    
    agent = reasoning_engines.LlamaIndexQueryPipelineAgent(
        model="gemini-2.0-flash",
        runnable_kwargs={"tools": [get_exchange_rate]},
        runnable_builder=runnable_with_tools_builder,
    )
    

    Por fim, teste o agente localmente:

    ADK

    for event in app.stream_query(
        user_id="USER_ID",
        message="What is the exchange rate from US dollars to SEK today?",
    ):
        print(event)
    

    em que USER_ID é um ID definido pelo usuário com um limite de 128 caracteres.

    LangGraph

    agent.query(input={"messages": [
        ("user", "What is the exchange rate from US dollars to SEK today?"),
    ]})
    

    LangChain

    agent.query(
        input="What is the exchange rate from US dollars to SEK today?"
    )
    

    AG2

    agent.query(
        input="What is the exchange rate from US dollars to SEK today?"
    )
    

    LlamaIndex

    agent.query(
        input="What is the exchange rate from US dollars to SEK today?"
    )
    

    Implantar um agente

    Para implantar o agente:

    ADK

    from vertexai import agent_engines
    
    remote_agent = agent_engines.create(
        app,
        requirements=["google-cloud-aiplatform[agent_engines,adk]"],
    )
    

    LangGraph

    from vertexai import agent_engines
    
    remote_agent = agent_engines.create(
        agent,
        requirements=["google-cloud-aiplatform[agent_engines,langchain]"],
    )
    

    LangChain

    from vertexai import agent_engines
    
    remote_agent = agent_engines.create(
        agent,
        requirements=["google-cloud-aiplatform[agent_engines,langchain]"],
    )
    

    AG2

    from vertexai import agent_engines
    
    remote_agent = agent_engines.create(
        agent,
        requirements=["google-cloud-aiplatform[agent_engines,ag2]"],
    )
    

    LlamaIndex

    from vertexai import agent_engines
    
    remote_agent = agent_engines.create(
        agent,
        requirements=["google-cloud-aiplatform[agent_engines,llama_index]"],
    )
    

    Isso cria um recurso reasoningEngine na Vertex AI.

    Usar um agente

    Teste o agente implantado enviando uma consulta:

    ADK

    for event in remote_agent.stream_query(
        user_id="USER_ID",
        message="What is the exchange rate from US dollars to SEK today?",
    ):
        print(event)
    

    LangGraph

    remote_agent.query(input={"messages": [
        ("user", "What is the exchange rate from US dollars to SEK today?"),
    ]})
    

    LangChain

    remote_agent.query(
        input="What is the exchange rate from US dollars to SEK today?"
    )
    

    AG2

    remote_agent.query(
        input="What is the exchange rate from US dollars to SEK today?"
    )
    

    LlamaIndex

    remote_agent.query(
        input="What is the exchange rate from US dollars to SEK today?"
    )
    

    Limpar

    Para evitar cobranças na conta do Google Cloud pelos recursos usados nesta página, siga as etapas abaixo.

    remote_agent.delete(force=True)
    

    A seguir