Agent Loop + Graph Engineer 工程化：把智能体循环变成可运维的图

import json, time

def checkpoint(state):
    with open("state.json", "w") as f:
        json.dump(state, f, ensure_ascii=False)

def run_graph(state, nodes, edges, start="planner", max_steps=20):
    node = start
    for _ in range(max_steps):
        t = time.time()
        state = nodes[node](state)
        state["trace"].append({"node": node, "ms": int((time.time() - t) * 1000)})
        checkpoint(state)
        node = edges[node](state)
        if node == "end":
            return state
    raise RuntimeError("budget exceeded")

def planner(s):
    return {**s, "outline": ["引子", "原理", "代码", "总结"], "i": 0}

def writer(s):
    i = s["i"]
    return {**s, "draft": s["draft"] + f"\n## {s['outline'][i]}\n...", "i": i + 1}

def reviewer(s):
    return {**s, "pass": s["i"] >= len(s["outline"])}

NODES = {"planner": planner, "writer": writer, "reviewer": reviewer}
EDGES = {
    "planner": lambda s: "writer",
    "writer": lambda s: "reviewer",
    "reviewer": lambda s: "end" if s["pass"] else "writer",
}

state = {"topic": "Agent Loop + Graph Engineer", "draft": "", "trace": []}
result = run_graph(state, NODES, EDGES)
print(result["draft"])