langgraph/docs/docs/cloud/how-tos/webhooks.md

Use Webhooks

You may wish to use webhooks in your client, especially when using async streams in case you want to update something in your service once the API call to LangGraph Cloud has finished running. To do so, you will need to expose an endpoint that can accept POST requests, and then pass it to your API request in the "webhook" parameter.

Currently, the SDK has not exposed this endpoint but you can access it through curl commands as follows.

The following endpoints accept webhook as a parameter:

• Create Run -> POST /thread/{thread_id}/runs
• Create Thread Cron -> POST /thread/{thread_id}/runs/crons
• Stream Run -> POST /thread/{thread_id}/runs/stream
• Wait Run -> POST /thread/{thread_id}/runs/wait
• Create Cron -> POST /runs/crons
• Stream Run Stateless -> POST /runs/stream
• Wait Run Stateless -> POST /runs/wait

In this example, we will show calling a webhook after streaming a run.

Setup

First, let's setup our assistant and thread:

=== "Python"

```python
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)
```

=== "Javascript"

```js
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"

```bash
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]' && \
curl --request POST \
    --url <DEPLOYMENT_URL>/threads \
    --header 'Content-Type: application/json' \
    --data '{}'
```

Output:

{
    '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
}

Use graph with a webhook

Now we can invoke a run with a webhook:

=== "Python"

```python
# create input
input = { "messages": [{ "role": "user", "content": "Hello!" }] }

async for chunk in client.runs.stream(
    thread_id=thread["thread_id"],
    assistant_id=assistant_id,
    input=input,
    stream_mode="events",
    webhook="your-webhook"
):
    # Do something with the stream output
    pass
```

=== "Javascript"

```js
// create input
const input = { messages: [{ role: "human", content: "Hello!" }] };

// stream events
const streamResponse = client.runs.stream(
  thread["thread_id"],
  assistantID,
  {
    input: input,
    webhook: "your-webhook"
  }
);
for await (const chunk of streamResponse) {
  // Do something with the stream output
}
```

=== "CURL"

```bash
curl --request POST \
    --url <DEPLOYMENT_URL>/threads/<THREAD_ID>/runs/stream \
    --header 'Content-Type: application/json' \
    --data '{
        "assistant_id": <ASSISTANT_ID>,
        "input" : {"messages":[{"role": "user", "content": "Hello!"}]},
        "webhook": <YOUR_WEBHOOK_URL>
    }'
```

And that's it! Now you can trigger your custom webhooks whenever you want in your LangGraph applications!