Deploy a public Langflow server - Langflow

By default, your Langflow server at http://localhost:7860 isn't exposed to the public internet. However, you can forward Langflow server traffic with a forwarding platform like ngrok or zrok to make your server public.

When your Langflow server is public, you can do things like deploy your Langflow MCP server externally, serve API requests, and share a flow's Playground publicly.

Prerequisites

On the machine where you plan to host your Langflow installation, install Langflow and a reverse proxy or forwarding service.

This guide uses ngrok, but you can use any similar reverse proxy or forwarding platform.

If you want to follow along with this guide, install ngrok and create an ngrok authtoken.

Expose your Langflow server with ngrok

Start Langflow:
bash
```
uv run langflow run
```
In another terminal window, use your ngrok authtoken to authenticate your local ngrok server:
bash
```
ngrok config add-authtoken NGROK_AUTHTOKEN
```
Use ngrok to expose your Langflow server to the public internet:
bash
```
ngrok http http://localhost:7860
```
This example assumes that you use the default Langflow listening address at http://localhost:7860. If you have a different listening address, you must modify this command accordingly.

The ngrok session starts in your terminal and deploys an ephemeral domain with no authentication. To add authentication or deploy a static domain, see the ngrok documentation.

The Forwarding line prints the forwarding address for your Langflow server:
```
Forwarding https://94b1-76-64-171-14.ngrok-free.app -> http://localhost:7860
```
The forwarding address acts as a reverse proxy for your Langflow server, and ngrok forwards your local traffic to this domain.
To verify that your Langflow server is publicly available, navigate to the forwarding address URL, such as https://94b1-76-64-171-14.ngrok-free.app.

Use a public Langflow server

When your Langflow server is public, you can do things like deploy your Langflow MCP server externally, serve API requests, and share a flow's Playground publicly.

Deploy your MCP server externally

After you deploy a public Langflow server, you can also access your Langflow projects' MCP servers publicly.

To do this, use your server's forwarding address when you connect a client to a Langflow MCP server.

Serve API requests

To send requests to a public Langflow server's Langflow API endpoints, use the server's domain as the base URL for your API requests. For example:

bash

curl -X POST \
  "PUBLIC_SERVER_DOMAIN/api/v1/webhook/FLOW_ID" \
  -H "Content-Type: application/json" \
  -H "x-api-key: LANGFLOW_API_KEY" \
  -d '{"data": "example-data"}'

:::tip When you create flows on public Langflow servers, the code snippets generated in the API access pane automatically use your public server's domain. :::

You also use your public domain when making Langflow API calls in scripts, including the code snippets that are automatically generated by Langflow. For example, the following code snippet calls an ngrok domain to trigger the specified flow (d764c4b8...):

```python
import requests

url = "https://3f7c-73-64-93-151.ngrok-free.app/api/v1/run/d764c4b8-5cec-4c0f-9de0-4b419b11901a"  # The complete API endpoint URL for this flow

# Request payload configuration
payload = {
    "output_type": "chat",
    "input_type": "chat",
    "input_value": "Hello"
}

# Request headers
headers = {
    "Content-Type": "application/json",
    "x-api-key": "LANGFLOW_API_KEY"
}

try:
    # Send API request
    response = requests.request("POST", url, json=payload, headers=headers)
    response.raise_for_status()  # Raise exception for bad status codes

    # Print response
    print(response.text)

except requests.exceptions.RequestException as e:
    print(f"Error making API request: {e}")
except ValueError as e:
    print(f"Error parsing response: {e}")
```

For a demo of the Langflow API in a script, see the Quickstart.

After you deploy a public Langflow server, you can use the Shareable Playground option to make a flow's Playground available at a public URL. If a user accesses this URL, they can interact with the flow's chat input and output and view the results without installing Langflow or generating a Langflow API key.

For more information, see Share a flow's Playground.