AgentCore CLI で Lambda を MCP ツール化する - Gateway 機能を試してみた 【備忘録】

# AgentCore CLI のインストール
npm install -g @aws/agentcore

agentcore create \
  --name GatewayDemo \
  --language python \
  --build container \
  --protocol http \
  --framework strands \
  --model-provider bedrock \
  --memory none \
  --network-mode PUBLIC

def lambda_handler(event, context):
    name = event.get("name", "World")
    return {
        "message": f"Hello, {name}! This response is from Lambda via AgentCore Gateway."
    }

# Lambda 用の IAM ロールを作成
aws iam create-role \
  --role-name hello-gateway-role \
  --assume-role-policy-document '{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"Service":"lambda.amazonaws.com"},"Action":"sts:AssumeRole"}]}'

aws iam attach-role-policy \
  --role-name hello-gateway-role \
  --policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole

# Lambda 関数のコードを zip 化
zip lambda_function.zip lambda_function.py

# Lambda 関数を作成
aws lambda create-function \
  --function-name hello-gateway \
  --runtime python3.13 \
  --handler lambda_function.lambda_handler \
  --role arn:aws:iam::123456789012:role/hello-gateway-role \
  --zip-file fileb://lambda_function.zip

arn:aws:lambda:ap-northeast-1:123456789012:function:hello-gateway

[
  {
    "name": "hello",
    "description": "名前を受け取って挨拶メッセージを返します。",
    "inputSchema": {
      "type": "object",
      "properties": {
        "name": {
          "type": "string",
          "description": "挨拶する相手の名前"
        }
      },
      "required": ["name"]
    }
  }
]

aws cognito-idp create-user-pool \
  --pool-name hello-gateway-pool \
  --query 'UserPool.Id' --output text

クライアント ID + シークレット → Cognito /oauth2/token → アクセストークン（スコープ付き）

# ドメインの作成（OAuth2 エンドポイント用）
aws cognito-idp create-user-pool-domain \
  --user-pool-id <USER_POOL_ID> \
  --domain hello-gateway-pool

# リソースサーバーとカスタムスコープの作成
aws cognito-idp create-resource-server \
  --user-pool-id <USER_POOL_ID> \
  --identifier "gateway" \
  --name "Gateway API" \
  --scopes '[{"ScopeName":"invoke","ScopeDescription":"Invoke gateway tools"}]'

# Gateway 用クライアントの作成
aws cognito-idp create-user-pool-client \
  --user-pool-id <USER_POOL_ID> \
  --client-name hello-gateway-m2m-client \
  --generate-secret \
  --allowed-o-auth-flows client_credentials \
  --allowed-o-auth-scopes "gateway/invoke" \
  --allowed-o-auth-flows-user-pool-client \
  --supported-identity-providers COGNITO

aws cognito-idp describe-user-pool-client \
  --user-pool-id <USER_POOL_ID> \
  --client-id <CLIENT_ID> \
  --query 'UserPoolClient.ClientSecret' --output text

agentcore add gateway \
  --name HelloGateway \
  --authorizer-type CUSTOM_JWT \
  --discovery-url https://cognito-idp.ap-northeast-1.amazonaws.com/<USER_POOL_ID>/.well-known/openid-configuration \
  --allowed-audience <CLIENT_ID> \
  --allowed-clients <CLIENT_ID> \
  --client-id <CLIENT_ID> \
  --client-secret <CLIENT_SECRET> \
  --runtimes GatewayDemo

agentcore add gateway-target \
  --name HelloLambda \
  --type lambda-function-arn \
  --lambda-arn arn:aws:lambda:ap-northeast-1:<ACCOUNT_ID>:function:hello-gateway \
  --tool-schema-file tools.json \
  --gateway HelloGateway

{                        
    "$schema": "https://schema.agentcore.aws.dev/v1/agentcore.json",
    "name": "GatewayDemo",                                                                                           
    "version": 1,
    "managedBy": "CDK",                                                                                              
    "tags": {                                                            
      "agentcore:created-by": "agentcore-cli",
      "agentcore:project-name": "GatewayDemo"
    },
    "runtimes": [
      {
        "name": "GatewayDemo",
        "build": "Container",
        "entrypoint": "main.py",
        "codeLocation": "app/GatewayDemo/",
        "runtimeVersion": "PYTHON_3_13",
        "networkMode": "PUBLIC",
        "protocol": "HTTP"
      }
    ],
    "memories": [],
    "credentials": [
      {
        "authorizerType": "OAuthCredentialProvider",
        "name": "HelloGateway-oauth",
        "discoveryUrl":
  "https://cognito-idp.ap-northeast-1.amazonaws.com/<USER_POOL_ID>/.well-known/openid-configuration",
        "vendor": "CustomOauth2",
        "managed": true,
        "usage": "inbound"
      }
    ],
    "evaluators": [],
    "onlineEvalConfigs": [],
    "agentCoreGateways": [
      {
        "name": "HelloGateway",
        "description": "Gateway for HelloGateway",
        "targets": [
          {
            "name": "HelloLambda",
            "targetType": "lambdaFunctionArn",
            "lambdaFunctionArn": {
              "lambdaArn": "arn:aws:lambda:ap-northeast-1:<ACCOUNT_ID>:function:hello-gateway",
              "toolSchemaFile": "tools.json"
            }
          }
        ],
        "authorizerType": "CUSTOM_JWT",
        "authorizerConfiguration": {
          "customJwtAuthorizer": {
            "discoveryUrl":
  "https://cognito-idp.ap-northeast-1.amazonaws.com/<USER_POOL_ID>/.well-known/openid-configuration",
            "allowedClients": [
              "<CLIENT_ID>"
            ]
          }
        },
        "enableSemanticSearch": true,
        "exceptionLevel": "NONE"
      }
    ],
    "unassignedTargets": [],
    "policyEngines": []
  }

agentcore deploy

agentcore status

export TOKEN=$(curl -s -X POST \
  "https://<DOMAIN>.auth.ap-northeast-1.amazoncognito.com/oauth2/token" \
  -H "Content-Type: application/x-www-form-urlencoded" \
  -d "grant_type=client_credentials&client_id=<CLIENT_ID>&client_secret=<CLIENT_SECRET>&scope=gateway/invoke" \
  | python3 -c "import sys,json; print(json.load(sys.stdin)['access_token'])")

curl -X POST <GATEWAY_URL>/mcp \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $TOKEN" \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{}}'

curl -X POST <GATEWAY_URL>/mcp \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $TOKEN" \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"HelloLambda___hello","arguments":{"name":"こーすけ"}}}'

# event の中身
{"name": "こーすけ"}

def lambda_handler(event, context):
    # どのツールとして呼ばれたか
    tool_name = context.client_context.custom['bedrockAgentCoreToolName']
    # Gateway ID
    gateway_id = context.client_context.custom['bedrockAgentCoreGatewayId']
    # ターゲット ID
    target_id = context.client_context.custom['bedrockAgentCoreTargetId']