实现和配置Story代理

任务 1：实现故事代理

故事代理是一个基于 Strands 的代理，在给定 Game 和 Action 列表作为上下文时，能够推进故事情节发展。我们将配置该代理与库存管理控制协议（MCP）服务器交互，以管理玩家的可用物品。

注意

在本教程中，我们将以”无状态”方式实现代理，每次调用都是包含完整消息历史的独立会话。生产环境中建议集成 Bedrock AgentCore 记忆系统。有关更多信息，请参阅在 Strands 中使用 AgentCore 记忆页面。

代理实现

要实现代理，请更新 packages/story/dungeon_adventure_story/agent 目录下的以下文件：

main.py

+

import uuid

import uvicorn
from bedrock_agentcore.runtime.models import PingStatus
from fastapi.responses import PlainTextResponse, StreamingResponse
from pydantic import BaseModel

from .agent import get_agent
from .init import app


class Action(BaseModel):
    role: str
    content: str


class InvokeInput(BaseModel):
    playerName: str
    genre: str
    actions: list[Action]


async def handle_invoke(input: InvokeInput):
    """Streaming handler for agent invocation"""
    messages = [{"role": "user", "content": [{"text": "Continue or create a new story..."}]}]
    for action in input.actions:
        messages.append({"role": action.role, "content": [{"text": action.content}]})

    with get_agent(input.playerName, input.genre, session_id=str(uuid.uuid4())) as agent:
        stream = agent.stream_async(messages)
        async for event in stream:
            print(event)
            content = event.get("event", {}).get("contentBlockDelta", {}).get("delta", {}).get("text")
            if content is not None:
                yield content
            elif event.get("event", {}).get("messageStop") is not None:
                yield "\n"


@app.post("/invocations", openapi_extra={"x-streaming": True}, response_class=PlainTextResponse)
async def invoke(input: InvokeInput) -> str:
    """Entry point for agent invocation"""
    return StreamingResponse(handle_invoke(input), media_type="text/event-stream")


@app.get("/ping")
def ping() -> str:
    # TODO: if running an async task, return PingStatus.HEALTHY_BUSY
    return PingStatus.HEALTHY


if __name__ == "__main__":
    uvicorn.run("dungeon_adventure_story.agent.main:app", port=8080)

+-

import uuid

import uvicorn
from bedrock_agentcore.runtime.models import PingStatus
from fastapi.responses import PlainTextResponse, StreamingResponse
from pydantic import BaseModel

from .agent import get_agent
from .init import app


class Action(BaseModel):
    role: str
    content: str


class InvokeInput(BaseModel):
    prompt: str
    session_id: str
    playerName: str
    genre: str
    actions: list[Action]


async def handle_invoke(input: InvokeInput):
    """Streaming handler for agent invocation"""
    with get_agent(session_id=input.session_id) as agent:
        stream = agent.stream_async(input.prompt)
    messages = [{"role": "user", "content": [{"text": "Continue or create a new story..."}]}]
    for action in input.actions:
        messages.append({"role": action.role, "content": [{"text": action.content}]})

    with get_agent(input.playerName, input.genre, session_id=str(uuid.uuid4())) as agent:
        stream = agent.stream_async(messages)
        async for event in stream:
            print(event)
            content = event.get("event", {}).get("contentBlockDelta", {}).get("delta", {}).get("text")
            if content is not None:
                yield content
            elif event.get("event", {}).get("messageStop") is not None:
                yield "\n"


@app.post("/invocations", openapi_extra={"x-streaming": True}, response_class=PlainTextResponse)
async def invoke(input: InvokeInput) -> str:
    """Entry point for agent invocation"""
    return StreamingResponse(handle_invoke(input), media_type="text/event-stream")


@app.get("/ping")
def ping() -> str:
    # TODO: if running an async task, return PingStatus.HEALTHY_BUSY
    return PingStatus.HEALTHY


if __name__ == "__main__":
    uvicorn.run("dungeon_adventure_story.agent.main:app", port=8080)

agent.py

+

import os
from contextlib import contextmanager

import boto3
from strands import Agent

from .agentcore_mcp_client import AgentCoreMCPClient

# Obtain the region and credentials
region = os.environ["AWS_REGION"]
boto_session = boto3.Session(region_name=region)
credentials = boto_session.get_credentials()


@contextmanager
def get_agent(player_name: str, genre: str, session_id: str):
    mcp_client = AgentCoreMCPClient.with_iam_auth(
        agent_runtime_arn=os.environ["INVENTORY_MCP_ARN"],
        credentials=credentials,
        region=region,
        session_id=session_id,
    )
    with mcp_client:
        yield Agent(
            system_prompt=f"""
You are running a text adventure game in the genre <genre>{genre}</genre> for player <player>{player_name}</player>.
Construct a scenario and give the player decisions to make.
Use the tools to manage the player's inventory as items are obtained or lost.
When adding, removing or updating items in the inventory, always list items to check the current state,
and be careful to match item names exactly. Item names in the inventory must be Title Case.
Ensure you specify a suitable emoji when adding items if available.
When starting a game, populate the inventory with a few initial items. Items should be a key part of the narrative.
Keep responses under 100 words.
""",
            tools=[*mcp_client.list_tools_sync()],
        )

+-

import os
from contextlib import contextmanager

from strands import Agent, tool
from strands_tools import current_time
import boto3
from strands import Agent

from .agentcore_mcp_client import AgentCoreMCPClient

# Define a custom tool
@tool
def add(a: int, b: int) -> int:
    return a + b
# Obtain the region and credentials
region = os.environ["AWS_REGION"]
boto_session = boto3.Session(region_name=region)
credentials = boto_session.get_credentials()


@contextmanager
def get_agent(session_id: str):
    yield Agent(
        system_prompt="""
You are an addition wizard.
Use the 'add' tool for addition tasks.
Refer to tools as your 'spellbook'.
""",
        tools=[add, current_time],
def get_agent(player_name: str, genre: str, session_id: str):
    mcp_client = AgentCoreMCPClient.with_iam_auth(
        agent_runtime_arn=os.environ["INVENTORY_MCP_ARN"],
        credentials=credentials,
        region=region,
        session_id=session_id,
    )
    with mcp_client:
        yield Agent(
            system_prompt=f"""
You are running a text adventure game in the genre <genre>{genre}</genre> for player <player>{player_name}</player>.
Construct a scenario and give the player decisions to make.
Use the tools to manage the player's inventory as items are obtained or lost.
When adding, removing or updating items in the inventory, always list items to check the current state,
and be careful to match item names exactly. Item names in the inventory must be Title Case.
Ensure you specify a suitable emoji when adding items if available.
When starting a game, populate the inventory with a few initial items. Items should be a key part of the narrative.
Keep responses under 100 words.
""",
            tools=[*mcp_client.list_tools_sync()],
        )

此配置将实现以下功能：

• 从代理负载中提取玩家信息、游戏类型和动作列表，
• 构建使用 SigV4 认证调用 MCP 服务器的客户端，以及
• 通过系统提示和 MCP 服务器工具构建代理。

任务 2：部署与测试

构建代码

要构建代码：

pnpm

pnpm nx run-many --target build --all

yarn

yarn nx run-many --target build --all

npm

npx nx run-many --target build --all

bun

bunx nx run-many --target build --all

提示

若遇到 lint 错误，可运行以下命令自动修复。

pnpm

pnpm nx run-many --target lint --configuration=fix --all

yarn

yarn nx run-many --target lint --configuration=fix --all

npm

npx nx run-many --target lint --configuration=fix --all

bun

bunx nx run-many --target lint --configuration=fix --all

部署应用程序

要部署应用程序，请运行以下命令：

pnpm

pnpm nx deploy infra dungeon-adventure-infra-sandbox/*

yarn

yarn nx deploy infra dungeon-adventure-infra-sandbox/*

npm

npx nx deploy infra dungeon-adventure-infra-sandbox/*

bun

bunx nx deploy infra dungeon-adventure-infra-sandbox/*

部署过程约需 2 分钟完成。

部署完成后，将看到类似以下输出（部分值已脱敏）：

dungeon-adventure-infra-sandbox-Application
dungeon-adventure-infra-sandbox-Application: deploying... [2/2]

 ✅  dungeon-adventure-infra-sandbox-Application

✨  部署时间：354秒

输出：
dungeon-adventure-infra-sandbox-Application.ElectroDbTableTableNameXXX = dungeon-adventure-infra-sandbox-Application-ElectroDbTableXXX-YYY
dungeon-adventure-infra-sandbox-Application.GameApiEndpointXXX = https://xxx.execute-api.region.amazonaws.com/prod/
dungeon-adventure-infra-sandbox-Application.GameUIDistributionDomainNameXXX = xxx.cloudfront.net
dungeon-adventure-infra-sandbox-Application.InventoryMcpArn = arn:aws:bedrock-agentcore:region:xxxxxxx:runtime/dungeonadventureventoryMcpServerXXXX-YYYY
dungeon-adventure-infra-sandbox-Application.StoryAgentArn = arn:aws:bedrock-agentcore:region:xxxxxxx:runtime/dungeonadventurecationStoryAgentXXXX-YYYY
dungeon-adventure-infra-sandbox-Application.UserIdentityUserIdentityIdentityPoolIdXXX = region:xxx
dungeon-adventure-infra-sandbox-Application.UserIdentityUserIdentityUserPoolIdXXX = region_xxx

测试 API

可通过以下方式测试 API：

• 启动代理服务器本地实例并使用 curl 调用，或
• 使用携带 JWT 令牌的 curl 调用已部署 API。

本地

运行以下命令启动本地代理服务器：

pnpm

INVENTORY_MCP_ARN=arn:aws:bedrock-agentcore:region:xxxxxxx:runtime/dungeonadventureventoryMcpServerXXXX-YYYY AWS_REGION=<region> pnpm nx run dungeon_adventure.story:agent-serve

yarn

INVENTORY_MCP_ARN=arn:aws:bedrock-agentcore:region:xxxxxxx:runtime/dungeonadventureventoryMcpServerXXXX-YYYY AWS_REGION=<region> yarn nx run dungeon_adventure.story:agent-serve

npm

INVENTORY_MCP_ARN=arn:aws:bedrock-agentcore:region:xxxxxxx:runtime/dungeonadventureventoryMcpServerXXXX-YYYY AWS_REGION=<region> npx nx run dungeon_adventure.story:agent-serve

bun

INVENTORY_MCP_ARN=arn:aws:bedrock-agentcore:region:xxxxxxx:runtime/dungeonadventureventoryMcpServerXXXX-YYYY AWS_REGION=<region> bunx nx run dungeon_adventure.story:agent-serve

警告

请使用 CDK 部署输出的 InventoryMcpArn 值，并指定目标 AWS_REGION。

代理服务器启动并运行后（无输出显示），运行以下命令进行调用：

curl -N -X POST http://127.0.0.1:8081/invocations \
  -d '{"genre":"superhero", "actions":[], "playerName":"UnnamedHero"}' \
  -H "Content-Type: application/json"

已部署

测试已部署代理需通过 Cognito 认证获取 JWT 令牌。首先设置环境变量：

# 从 CDK 输出中设置 Cognito 用户池 ID 和客户端 ID
export POOL_ID="<CDK 输出的 UserPoolId>"
export CLIENT_ID="<CDK 输出的 UserPoolClientId>"
export REGION="<区域>"

创建测试用户并获取认证令牌：

# 创建用户
aws cognito-idp admin-create-user \
  --user-pool-id $POOL_ID \
  --username "testuser" \
  --temporary-password "TempPass123!" \
  --region $REGION \
  --message-action SUPPRESS > /dev/null

# 设置永久密码（请替换为更安全的密码！）
aws cognito-idp admin-set-user-password \
  --user-pool-id $POOL_ID \
  --username "testuser" \
  --password "PermanentPass123!" \
  --region $REGION \
  --permanent > /dev/null

# 用户认证并获取 ID 令牌
export BEARER_TOKEN=$(aws cognito-idp initiate-auth \
  --client-id "$CLIENT_ID" \
  --auth-flow USER_PASSWORD_AUTH \
  --auth-parameters USERNAME='testuser',PASSWORD='PermanentPass123!' \
  --region $REGION | jq -r '.AuthenticationResult.IdToken')

警告

使用 CDK 输出的 UserIdentityUserIdentityUserPoolIdXXX 作为 POOL_ID，并确保使用对应的客户端 ID。

通过 Bedrock AgentCore 运行时 URL 调用已部署代理：

# 设置 CDK 输出的 Story Agent ARN
export AGENT_ARN="<CDK 输出的 StoryAgentArn>"

# URL 编码 ARN
export ENCODED_ARN=$(echo $AGENT_ARN | sed 's/:/%3A/g' | sed 's/\//%2F/g')

# 构造调用 URL
export MCP_URL="https://bedrock-agentcore.$REGION.amazonaws.com/runtimes/$ENCODED_ARN/invocations?qualifier=DEFAULT"

# 调用代理
curl -N -X POST "$MCP_URL" \
  -H "authorization: Bearer $BEARER_TOKEN" \
  -H "Content-Type: application/json" \
  -H "X-Amzn-Bedrock-AgentCore-Runtime-Session-Id: abcdefghijklmnopqrstuvwxyz-123456789" \
  -d '{"genre":"superhero", "actions":[], "playerName":"UnnamedHero"}'

注意

URL 编码是正确格式化 Bedrock AgentCore API 端点 ARN 的必要步骤。

若命令运行成功，将看到类似以下事件流：

data: {"init_event_loop": true}

data: {"start": true}

data: {"start_event_loop": true}

data: {"event": {"messageStart": {"role": "assistant"}}}

data: {"event": {"contentBlockDelta": {"delta": {"text": "Welcome"}, "contentBlockIndex": 0}}}

...

恭喜！您已成功在 Bedrock AgentCore 运行时上构建并部署首个 Strands 代理！🎉🎉🎉