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在 AgentCore 閘道中呼叫工具 - Amazon Bedrock AgentCore

在 AgentCore 閘道中呼叫工具

若要呼叫特定工具,請對閘道的 MCP 端點提出 POST 請求,並在請求內文、工具名稱和引數中指定 tools/call作為方法:

POST /mcp HTTP/1.1 Host: ${GatewayEndpoint} Content-Type: application/json Authorization: ${Authorization header} ${RequestBody}

取代以下的值:

  • ${GatewayEndpoint} – 閘道的 URL,如 CreateGateway API 的回應所提供。

  • ${Authorization header} – 當您設定傳入授權時,來自身分提供者的授權憑證。

  • ${RequestBody} – 請求內文的 JSON 承載,如模型內容通訊協定 (MCP) 中的呼叫工具所指定。包含 tools/call做為 method,並包含 工具name的 及其 arguments

回應會傳回工具傳回的內容和相關聯的中繼資料。

呼叫工具的程式碼範例

若要查看閘道中列出可用工具的範例,請選取下列其中一種方法:

範例
curl
  1. 下列 curl 請求顯示透過 ID 為 searchProducts的閘道呼叫 工具的範例請求mygateway-abcdefghij

    curl -X POST \ https://mygateway-abcdefghij.gateway.bedrock-agentcore.us-west-2.amazonaws.com/mcp \ -H "Content-Type: application/json" \ -H "Authorization: Bearer YOUR_ACCESS_TOKEN" \ -d '{ "jsonrpc": "2.0", "id": "invoke-tool-request", "method": "tools/call", "params": { "name": "searchProducts", "arguments": { "query": "wireless headphones", "category": "Electronics", "maxResults": 2, "priceRange": { "min": 50.00, "max": 200.00 } } } }'
Python requests package
  1. import requests import json def call_tool(gateway_url, access_token, tool_name, arguments): headers = { "Content-Type": "application/json", "Authorization": f"Bearer {access_token}" } payload = { "jsonrpc": "2.0", "id": "call-tool-request", "method": "tools/call", "params": { "name": tool_name, "arguments": arguments } } response = requests.post(gateway_url, headers=headers, json=payload) return response.json() # Example usage gateway_url = "https://${GatewayEndpoint}/mcp" # Replace with your actual gateway endpoint access_token = "${AccessToken}" # Replace with your actual access token result = call_tool( gateway_url, access_token, "openapi-target-1___get_orders_byId", # Replace with <{TargetId}__{ToolName}> {"orderId": "ORD-12345-67890", "customerId": "CUST-98765"} ) print(json.dumps(result, indent=2))
MCP Client
  1. from mcp import ClientSession from mcp.client.streamable_http import streamablehttp_client import asyncio async def execute_mcp( url, token, tool_params, headers=None ): default_headers = { "Authorization": f"Bearer {token}" } headers = {**default_headers, **(headers or {})} async with streamablehttp_client( url=url, headers=headers, ) as ( read_stream, write_stream, callA, ): async with ClientSession(read_stream, write_stream) as session: # 1. Perform initialization handshake print("Initializing MCP...") _init_response = await session.initialize() print(f"MCP Server Initialize successful! - {_init_response}") # 2. Call specific tool print(f"Calling tool: {tool_params['name']}") tool_response = await session.call_tool( name=tool_params['name'], arguments=tool_params['arguments'] ) print(f"Tool response: {tool_response}") return tool_response async def main(): url = "https://${GatewayEndpoint}/mcp" token = "your_bearer_token_here" tool_params = { "name": "LambdaTarget___get_order_tool", "arguments": { "orderId": "order123" } } await execute_mcp( url=url, token=token, tool_params=tool_params ) if __name__ == "__main__": asyncio.run(main())
Strands MCP Client
  1. 注意:這是用於叫用代理程式

    from strands.tools.mcp.mcp_client import MCPClient from mcp.client.streamable_http import streamablehttp_client def create_streamable_http_transport(mcp_url: str, access_token: str): return streamablehttp_client(mcp_url, headers={"Authorization": f"Bearer {access_token}"}) def run_agent(mcp_url: str, access_token: str): mcp_client = MCPClient(lambda: create_streamable_http_transport(mcp_url, access_token)) with mcp_client: result = mcp_client.call_tool_sync( tool_use_id="tool-123", # A unique ID for the tool call name="openapi-target-1___get_orders", # The name of the tool to invoke arguments={} # A dictionary of arguments for the tool ) print(result) url = {gatewayUrl} token = {AccessToken} run_agent(url, token)
LangGraph MCP Client
  1. 注意:這是用於叫用代理程式

    import asyncio from langgraph.prebuilt import create_react_agent def execute_agent( user_prompt, model_id, region, tools ): model = ChatBedrock(model_id=model_id, region_name=region) agent = create_react_agent(model, tools) _response = asyncio.run(agent.ainvoke({ "messages": user_prompt })) _response = _response.get('messages', {})[1].content print( f"Invoke Langchain Agents Response" f"Response - \n{_response}\n" ) return _response

錯誤

tools/call 操作可能會傳回下列類型的錯誤:

  • 在 HTTP 狀態碼中傳回的錯誤:

    AuthenticationError

    由於身分驗證登入資料無效,請求失敗。

    HTTP 狀態碼:401

    AuthorizationError

    呼叫者沒有叫用工具的許可。

    HTTP 狀態碼:403

    ResourceNotFoundError

    指定的工具不存在。

    HTTP 狀態碼:404

    ValidationError

    提供的引數不符合工具的輸入結構描述。

    HTTP 狀態碼:400

    ToolExecutionError

    執行工具時發生錯誤。

    HTTP 狀態碼:500

    InternalServerError

    發生內部伺服器錯誤。

    HTTP 狀態碼:500

  • MCP 錯誤。如需這些錯誤類型的詳細資訊,請參閱模型內容通訊協定 (MCP) 文件中的錯誤處理