A Coding Guide to Design and Orchestrate Advanced ReAct-Based Multi-Agent Workflows with AgentScope and OpenAI

!pip -q install "agentscope>=0.1.5" pydantic nest_asyncio


import os, json, re
from getpass import getpass
from typing import Literal
from pydantic import BaseModel, Field
import nest_asyncio
nest_asyncio.apply()


from agentscope.agent import ReActAgent
from agentscope.message import Msg, TextBlock
from agentscope.model import OpenAIChatModel
from agentscope.formatter import OpenAIChatFormatter
from agentscope.memory import InMemoryMemory
from agentscope.tool import Toolkit, ToolResponse, execute_python_code
from agentscope.pipeline import MsgHub, sequential_pipeline


if not os.environ.get("OPENAI_API_KEY"):
   os.environ["OPENAI_API_KEY"] = getpass("Enter OPENAI_API_KEY (hidden): ")


OPENAI_MODEL = os.environ.get("OPENAI_MODEL", "gpt-4o-mini")

RUNBOOK = [
   {"id": "P0", "title": "Severity policy", "text": "P0 critical outage, P1 major degradation, P2 minor issue"},
   {"id": "IR1", "title": "Incident Triage Checklist", "text": "Assess blast radius, timeline, deployments, errors, mitigation"},
   {"id": "SEC7", "title": "Phishing Escalation", "text": "Disable account, reset sessions, block sender, preserve evidence"},
]


def _score(q, d):
   q = set(re.findall(r"[a-z0-9]+", q.lower()))
   d = re.findall(r"[a-z0-9]+", d.lower())
   return sum(1 for w in d if w in q) / max(1, len(d))


async def search_runbook(query: str, top_k: int = 2) -> ToolResponse:
   ranked = sorted(RUNBOOK, key=lambda r: _score(query, r["title"] + r["text"]), reverse=True)[: max(1, int(top_k))]
   text = "\n\n".join(f"[{r['id']}] {r['title']}\n{r['text']}" for r in ranked)
   return ToolResponse(content=[TextBlock(type="text", text=text)])


toolkit = Toolkit()
toolkit.register_tool_function(search_runbook)
toolkit.register_tool_function(execute_python_code)

def make_model():
   return OpenAIChatModel(
       model_name=OPENAI_MODEL,
       api_key=os.environ["OPENAI_API_KEY"],
       generate_kwargs={"temperature": 0.2},
   )


class Route(BaseModel):
   lane: Literal["triage", "analysis", "report", "unknown"] = Field(...)
   goal: str = Field(...)


router = ReActAgent(
   name="Router",
   sys_prompt="Route the request to triage, analysis, or report and output structured JSON only.",
   model=make_model(),
   formatter=OpenAIChatFormatter(),
   memory=InMemoryMemory(),
)


triager = ReActAgent(
   name="Triager",
   sys_prompt="Classify severity and immediate actions using runbook search when useful.",
   model=make_model(),
   formatter=OpenAIChatFormatter(),
   memory=InMemoryMemory(),
   toolkit=toolkit,
)


analyst = ReActAgent(
   name="Analyst",
   sys_prompt="Analyze logs and compute summaries using python tool when helpful.",
   model=make_model(),
   formatter=OpenAIChatFormatter(),
   memory=InMemoryMemory(),
   toolkit=toolkit,
)


writer = ReActAgent(
   name="Writer",
   sys_prompt="Write a concise incident report with clear structure.",
   model=make_model(),
   formatter=OpenAIChatFormatter(),
   memory=InMemoryMemory(),
)


reviewer = ReActAgent(
   name="Reviewer",
   sys_prompt="Critique and improve the report with concrete fixes.",
   model=make_model(),
   formatter=OpenAIChatFormatter(),
   memory=InMemoryMemory(),
)

LOGS = """timestamp,service,status,latency_ms,error
2025-12-18T12:00:00Z,checkout,200,180,false
2025-12-18T12:00:05Z,checkout,500,900,true
2025-12-18T12:00:10Z,auth,200,120,false
2025-12-18T12:00:12Z,checkout,502,1100,true
2025-12-18T12:00:20Z,search,200,140,false
2025-12-18T12:00:25Z,checkout,500,950,true
"""


def msg_text(m: Msg) -> str:
   blocks = m.get_content_blocks("text")
   if blocks is None:
       return ""
   if isinstance(blocks, str):
       return blocks
   if isinstance(blocks, list):
       return "\n".join(str(x) for x in blocks)
   return str(blocks)

async def run_demo(user_request: str):
   route_msg = await router(Msg("user", user_request, "user"), structured_model=Route)
   lane = (route_msg.metadata or {}).get("lane", "unknown")


   if lane == "triage":
       first = await triager(Msg("user", user_request, "user"))
   elif lane == "analysis":
       first = await analyst(Msg("user", user_request + "\n\nLogs:\n" + LOGS, "user"))
   elif lane == "report":
       draft = await writer(Msg("user", user_request, "user"))
       first = await reviewer(Msg("user", "Review and improve:\n\n" + msg_text(draft), "user"))
   else:
       first = Msg("system", "Could not route request.", "system")


   async with MsgHub(
       participants=[triager, analyst, writer, reviewer],
       announcement=Msg("Host", "Refine the final answer collaboratively.", "assistant"),
   ):
       await sequential_pipeline([triager, analyst, writer, reviewer])


   return {"route": route_msg.metadata, "initial_output": msg_text(first)}


result = await run_demo(
   "We see repeated 5xx errors in checkout. Classify severity, analyze logs, and produce an incident report."
)
print(json.dumps(result, indent=2))