# Deploy a flow using development server
:::{admonition} Experimental feature
This is an experimental feature, and may change at any time. Learn [more](../faq.md#stable-vs-experimental).
:::

Once you have created and thoroughly tested a flow, you can use it as an HTTP endpoint.

::::{tab-set}
:::{tab-item} CLI
:sync: CLI
We are going to use the [web-classification](https://github.com/microsoft/promptflow/tree/main/examples/flows/standard/web-classification/) as
an example to show how to deploy a flow.

Please ensure you have [create the connection](../manage-connections.md#create-a-connection) required by flow, if not, you could
refer to [Setup connection for web-classification](https://github.com/microsoft/promptflow/tree/main/examples/flows/standard/web-classification).

Note: We will use relevant environment variable ({connection_name}_{key_name}) to override connection configurations in 
serving mode, white space in connection name will be removed directly from environment variable name. For instance, 
if there is a custom connection named 'custom_connection' with a configuration key called 'chat_deployment_name,' the 
function will attempt to retrieve 'chat_deployment_name' from the environment variable 
'CUSTOM_CONNECTION_CHAT_DEPLOYMENT_NAME' by default. If the environment variable is not set, it will use the original 
value as a fallback.


The following CLI commands allows you serve a flow folder as an endpoint. By running this command, a [flask](https://flask.palletsprojects.com/en/) app will start in the environment where command is executed, please ensure all prerequisites required by flow have been installed.
```bash
# Serve the flow at localhost:8080
pf flow serve --source <path-to-your-flow-folder> --port 8080 --host localhost
```

The expected result is as follows if the flow served successfully, and the process will keep alive until it be killed manually.

![img](../../media/how-to-guides/deploy_flow.png)
:::
:::{tab-item} VS Code Extension
:sync: VSC
In visual editor, choose:
![img](../../media/how-to-guides/vscode_export.png)
then choose format:
![img](../../media/how-to-guides/vscode_export_as_local_app.png)
then in yaml editor:
![img](../../media/how-to-guides/vscode_start_local_app.png)
:::
::::

## Test endpoint
::::{tab-set}
:::{tab-item} Bash
You could open another terminal to test the endpoint with the following command:
```bash
curl http://localhost:8080/score --data '{"url":"https://play.google.com/store/apps/details?id=com.twitter.android"}' -X POST  -H "Content-Type: application/json"
```
:::
:::{tab-item} PowerShell
You could open another terminal to test the endpoint with the following command:
```powershell
Invoke-WebRequest -URI http://localhost:8080/score -Body '{"url":"https://play.google.com/store/apps/details?id=com.twitter.android"}' -Method POST  -ContentType "application/json"
```
:::
:::{tab-item} Test Page
The development server has a built-in web page you can use to test the flow. Open 'http://localhost:8080' in your browser.
![img](../../media/how-to-guides/deploy_flow_test_page.png)
:::
::::

## Next steps
- Try the example [here](https://github.com/microsoft/promptflow/tree/main/examples/flows/standard/web-classification/).
- See how to [deploy a flow using docker](deploy-using-docker.md).
- See how to [deploy a flow using kubernetes](deploy-using-kubernetes.md).
