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使用定时任务

有时你不想基于用户交互来运行图,而是希望按计划调度图的运行 - 例如,如果你希望图每周为你的团队撰写并发送待办事项邮件。LangGraph Platform 允许你通过使用 Crons 客户端来实现这一点,而无需编写自己的脚本。要调度图任务,你需要传递一个 cron 表达式来告知客户端你希望何时运行图。Cron 任务在后台运行,不会干扰图的正常调用。

设置

首先,让我们设置 SDK 客户端、助手和线程:

from langgraph_sdk import get_client

client = get_client(url=<DEPLOYMENT_URL>)
# Using the graph deployed with the name "agent"
assistant_id = "agent"
# create thread
thread = await client.threads.create()
print(thread)

import { Client } from "@langchain/langgraph-sdk";

const client = new Client({ apiUrl: <DEPLOYMENT_URL> });
// Using the graph deployed with the name "agent"
const assistantId = "agent";
// create thread
const thread = await client.threads.create();
console.log(thread);

curl --request POST \
    --url <DEPLOYMENT_URL>/assistants/search \
    --header 'Content-Type: application/json' \
    --data '{
        "limit": 10,
        "offset": 0
    }' | jq -c 'map(select(.config == null or .config == {})) | .[0].graph_id' && \
curl --request POST \
    --url <DEPLOYMENT_URL>/threads \
    --header 'Content-Type: application/json' \
    --data '{}'

输出:

{
    'thread_id': '9dde5490-2b67-47c8-aa14-4bfec88af217',
    'created_at': '2024-08-30T23:07:38.242730+00:00',
    'updated_at': '2024-08-30T23:07:38.242730+00:00',
    'metadata': {},
    'status': 'idle',
    'config': {},
    'values': None
}

线程上的定时任务

要创建与特定线程关联的定时任务,你可以编写:

# This schedules a job to run at 15:27 (3:27PM) every day
cron_job = await client.crons.create_for_thread(
    thread["thread_id"],
    assistant_id,
    schedule="27 15 * * *",
    input={"messages": [{"role": "user", "content": "What time is it?"}]},
)

// This schedules a job to run at 15:27 (3:27PM) every day
const cronJob = await client.crons.create_for_thread(
  thread["thread_id"],
  assistantId,
  {
    schedule: "27 15 * * *",
    input: { messages: [{ role: "user", content: "What time is it?" }] }
  }
);

curl --request POST \
    --url <DEPLOYMENT_URL>/threads/<THREAD_ID>/runs/crons \
    --header 'Content-Type: application/json' \
    --data '{
        "assistant_id": <ASSISTANT_ID>,
    }'

请注意,删除不再有用的 Cron 任务**非常**重要。否则你可能会产生不需要的 LLM API 费用!你可以使用以下代码删除 Cron 任务:

await client.crons.delete(cron_job["cron_id"])

await client.crons.delete(cronJob["cron_id"]);

curl --request DELETE \
    --url <DEPLOYMENT_URL>/runs/crons/<CRON_ID>

无状态定时任务

你还可以使用以下代码创建无状态定时任务:

# This schedules a job to run at 15:27 (3:27PM) every day
cron_job_stateless = await client.crons.create(
    assistant_id,
    schedule="27 15 * * *",
    input={"messages": [{"role": "user", "content": "What time is it?"}]},
)

// This schedules a job to run at 15:27 (3:27PM) every day
const cronJobStateless = await client.crons.create(
  assistantId,
  {
    schedule: "27 15 * * *",
    input: { messages: [{ role: "user", content: "What time is it?" }] }
  }
);

curl --request POST \
    --url <DEPLOYMENT_URL>/runs/crons \
    --header 'Content-Type: application/json' \
    --data '{
        "assistant_id": <ASSISTANT_ID>,
    }'

再次提醒,一旦完成使用,请记得删除你的任务!

await client.crons.delete(cron_job_stateless["cron_id"])

await client.crons.delete(cronJobStateless["cron_id"]);

curl --request DELETE \
    --url <DEPLOYMENT_URL>/runs/crons/<CRON_ID>