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使用 Cron 作业

有时您不想根据用户交互来运行您的图，而是希望安排您的图按计划运行——例如，如果您希望您的图能够为您的团队撰写并发送每周待办事项电子邮件。LangGraph Platform 允许您使用 Crons 客户端实现这一点，而无需编写自己的脚本。要安排图作业，您需要传递一个 cron 表达式来通知客户端您希望何时运行该图。Cron 作业在后台运行，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 Cron 作业

要创建与特定线程关联的 cron 作业，您可以编写

# 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 作业非常重要。否则，您可能会产生不必要的 LLM API 费用！您可以使用以下代码删除 Cron 作业

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 Cron 作业

您还可以使用以下代码创建无状态 cron 作业

# 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>,
    }'

同样，请记住在完成作业后将其删除！

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>