> Fetch clean Markdown by appending `.md` to any page URL under https://signalwire.com/docs or requesting it with the HTTP header `Accept: text/markdown`. The root index at https://signalwire.com/docs/llms.txt lists the available documentation indexes.

# List call flow versions

GET https://%7BYour_Space_Name%7D.signalwire.com/api/fabric/resources/call_flow/{id}/versions

Lists the saved revisions of one Call Flow. Use it to review the visual resource's history or select a version for deployment; use [Get call flow](/docs/apis/rest/call-flows/get-call-flow) for the current editable resource, or SWML Scripts when you do not need the Call Flow Builder deployment lifecycle.

#### Permissions

The API token used to authenticate must have the following scope(s) enabled to make a successful request: _Voice_, _Messaging_, _Fax_, or _Video_.

[Learn more about API scopes](/docs/platform/your-signalwire-api-space).

Reference: https://signalwire.com/docs/apis/rest/call-flows/list-call-flow-versions

## Authentication

- `Authorization` header (basic auth, required) — SignalWire Basic Authentication using Project ID and API Token. The client sends HTTP requests with the Authorization header containing the word Basic followed by a space and a base64-encoded string of project_id:token. The project ID will be used as the username and the API token as the password. Example: ``` Authorization: Basic base64(project_id:token) ```

## Request

### Path parameters

- `id` (string, required) — The unique identifier of the Call Flow.

## Response

### 200

The request has succeeded.

- `data` (list of CallFlowVersion, required) — List of Call Flow Versions
- `links` (CallFlowVersionsPaginationResponse, required)

## Errors

### 401 Unauthorized Error

Access is unauthorized.

- `error` (enum, required)
  - Allowed values: `Unauthorized`

### 404 Not Found Error

The server cannot find the requested resource.

- `error` (enum, required)
  - Allowed values: `Not Found`

### 500 Internal Server Error

An internal server error occurred.

- `error` (enum, required)
  - Allowed values: `Internal Server Error`

## Types

### CallFlowVersion

- `id` (string, required) — The unique identifier of the version.
- `version` (string, required) — The version number.
- `created_at` (string, required) — The creation timestamp.
- `updated_at` (string, required) — The last update timestamp.
- `flow_data` (CallFlowVersionFlowData, optional) — Call Flow Builder state, stored as an opaque JSON object.
- `relayml` (CallFlowVersionRelayml, optional) — The calling SWML document this version snapshots. Uses [calling SWML methods](/docs/swml/reference/calling).

### CallFlowVersionsPaginationResponse

- `self` (string, required) — Link of the current page
- `first` (string, required) — Link to the first page
- `next` (string, required) — Link to the next page
- `prev` (string, optional) — Link to the previous page

### CallFlowVersionFlowData

Call Flow Builder state, stored as an opaque JSON object.

### CallFlowVersionRelayml

The calling SWML document this version snapshots. Uses [calling SWML methods](/docs/swml/reference/calling).

## Examples

**Response**

```json
{
  "data": [
    {
      "id": "3fa85f64-5717-4562-b3fc-2c963f66afa6",
      "version": "1.0.0",
      "created_at": "2024-05-06T12:20:00Z",
      "updated_at": "2024-05-06T12:25:00Z",
      "flow_data": {},
      "relayml": {
        "sections": {
          "main": [
            {
              "play": {
                "url": "https://cdn.signalwire.com/swml/audio.mp3"
              }
            }
          ]
        },
        "version": "1.0.0"
      }
    }
  ],
  "links": {
    "self": "https://example.signalwire.com/api/fabric/resources/call_flow/993ed018-9e79-4e50-b97b-984bd5534095/versions?page_number=0&page_size=50",
    "first": "https://example.signalwire.com/api/fabric/resources/call_flow/993ed018-9e79-4e50-b97b-984bd5534095/versions?page_number=0&page_size=50",
    "next": "https://example.signalwire.com/api/fabric/resources/call_flow/993ed018-9e79-4e50-b97b-984bd5534095/versions?page_number=1&page_size=50"
  }
}
```

**SDK Code**

```python Call Flow version list
import requests

url = "https://{your_space_name}.signalwire.com/api/fabric/resources/call_flow/id/versions"

response = requests.get(url, auth=("<project_id>", "<api_token>"))

print(response.json())
```

```javascript Call Flow version list
const url = 'https://{your_space_name}.signalwire.com/api/fabric/resources/call_flow/id/versions';
const credentials = btoa("<project_id>:<api_token>");

const options = {method: 'GET', headers: {Authorization: `Basic ${credentials}`}};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go Call Flow version list
package main

import (
	"fmt"
	"net/http"
	"io"
)

func main() {

	url := "https://{your_space_name}.signalwire.com/api/fabric/resources/call_flow/id/versions"

	req, _ := http.NewRequest("GET", url, nil)

	req.SetBasicAuth("<project_id>", "<api_token>")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby Call Flow version list
require 'uri'
require 'net/http'

url = URI("https://{your_space_name}.signalwire.com/api/fabric/resources/call_flow/id/versions")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Get.new(url)
request.basic_auth("<project_id>", "<api_token>")

response = http.request(request)
puts response.read_body
```

```java Call Flow version list
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.get("https://{your_space_name}.signalwire.com/api/fabric/resources/call_flow/id/versions")
  .basicAuth("<project_id>", "<api_token>")
  .asString();
```

```php Call Flow version list
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('GET', 'https://{your_space_name}.signalwire.com/api/fabric/resources/call_flow/id/versions', [
  'headers' => [
  ],
    'auth' => ['<project_id>', '<api_token>'],
]);

echo $response->getBody();
```

```csharp Call Flow version list
using RestSharp;
using RestSharp.Authenticators;

var client = new RestClient("https://{your_space_name}.signalwire.com/api/fabric/resources/call_flow/id/versions");
client.Authenticator = new HttpBasicAuthenticator("<project_id>", "<api_token>");
var request = new RestRequest(Method.GET);

IRestResponse response = client.Execute(request);
```

```swift Call Flow version list
import Foundation

let credentials = Data("<project_id>:<api_token>".utf8).base64EncodedString()

let headers = ["Authorization": "Basic \(credentials)"]

let request = NSMutableURLRequest(url: NSURL(string: "https://{your_space_name}.signalwire.com/api/fabric/resources/call_flow/id/versions")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "GET"
request.allHTTPHeaderFields = headers

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```