> 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.

# Create call flow

POST https://%7BYour_Space_Name%7D.signalwire.com/api/fabric/resources/call_flows
Content-Type: application/json

Creates a visual Call Flow in your SignalWire project. The new flow becomes a reusable call handler that can be edited in Call Flow Builder and assigned to phone numbers or other routing resources. Use [Create SWML Script](/docs/apis/rest/swml-scripts/create-swml-script) for directly authored SWML, or [Create Relay application](/docs/apis/rest/relay-application/create-relay-application) for a Server SDK handler.

#### 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/create-call-flow

## 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

### Body (application/json)

This endpoint expects a CallFlowCreateRequest.

- `title` (string, required) — The name of the Call Flow
- `flow_data` (CallFlowCreateRequestFlowData, optional) — Call Flow Builder state, stored as an opaque JSON object. Optional but must be paired with `relayml` — provide both fields together or omit both. When both are omitted, SignalWire creates a starter Call Flow.
- `relayml` (CallFlowCreateRequestRelayml, optional) — The calling SWML document this Call Flow should execute. Uses [calling SWML methods](/docs/swml/reference/calling). Optional but must be paired with `flow_data` — provide both fields together or omit both. When both are omitted, SignalWire creates a starter SWML document.

## Response

### 201

The request has succeeded and a new resource has been created as a result.

- `id` (string, required) — Unique ID of the Call Flow.
- `project_id` (string, required) — Unique ID of the Project.
- `display_name` (string, required) — Display name of the Call Flow Fabric Resource
- `type` (enum, required) — Type of the Fabric Resource
  - Allowed values: `call_flow`
- `created_at` (datetime, required) — Date and time when the resource was created.
- `updated_at` (datetime, required) — Date and time when the resource was updated.
- `call_flow` (CallFlow, required) — Call Flow data.

## 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`

### 422 Unprocessable Entity Error

The request contains invalid parameters. See errors for details.

- `errors` (list of Types.StatusCodes.RestApiErrorItem, required) — List of validation errors.

### 500 Internal Server Error

An internal server error occurred.

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

## Types

### CallFlowCreateRequestFlowData

Call Flow Builder state, stored as an opaque JSON object. Optional but must be paired with `relayml` — provide both fields together or omit both. When both are omitted, SignalWire creates a starter Call Flow.

### CallFlowCreateRequestRelayml

The calling SWML document this Call Flow should execute. Uses [calling SWML methods](/docs/swml/reference/calling). Optional but must be paired with `flow_data` — provide both fields together or omit both. When both are omitted, SignalWire creates a starter SWML document.

### CallFlow

- `id` (string, required) — Unique ID of a Call Flow.
- `title` (string, required) — The name of the Call Flow
- `flow_data` (CallFlowFlowData, optional) — Call Flow Builder state, stored as an opaque JSON object. Produced and consumed by the SignalWire Call Flow Builder UI; not used by SWML execution.
- `relayml` (CallFlowRelayml, optional) — The calling SWML document this Call Flow executes. Uses [calling SWML methods](/docs/swml/reference/calling).
- `document_version` (integer, optional) — The current revision of the call flow. Every update must increase this number.

### Types.StatusCodes.RestApiErrorItem

Details about a specific error.

- `type` (string, required) — The category of error.
- `code` (string, required) — A specific error code.
- `message` (string, required) — A description of what caused the error.
- `url` (string, required) — A link to documentation about this error.
- `attribute` (string, optional, nullable) — The request parameter that caused the error, if applicable.

### CallFlowFlowData

Call Flow Builder state, stored as an opaque JSON object. Produced and consumed by the SignalWire Call Flow Builder UI; not used by SWML execution.

### CallFlowRelayml

The calling SWML document this Call Flow executes. Uses [calling SWML methods](/docs/swml/reference/calling).

## Examples

**Request**

```json
{
  "title": "Welcome Call Flow",
  "relayml": {
    "sections": {
      "main": [
        {
          "play": {
            "url": "https://cdn.signalwire.com/swml/audio.mp3"
          }
        }
      ]
    },
    "version": "1.0.0"
  }
}
```

**Response**

```json
{
  "id": "993ed018-9e79-4e50-b97b-984bd5534095",
  "project_id": "1313fe58-5e14-4c11-bbe7-6fdfa11fe780",
  "display_name": "Welcome Call Flow",
  "type": "call_flow",
  "created_at": "2024-05-06T12:20:00Z",
  "updated_at": "2024-05-06T12:25:00Z",
  "call_flow": {
    "id": "993ed018-9e79-4e50-b97b-984bd5534095",
    "title": "Welcome Call Flow",
    "flow_data": {},
    "relayml": {
      "sections": {
        "main": [
          {
            "play": {
              "url": "https://cdn.signalwire.com/swml/audio.mp3"
            }
          }
        ]
      },
      "version": "1.0.0"
    },
    "document_version": 1
  }
}
```

**SDK Code**

```python Welcome Call Flow
import requests

url = "https://{your_space_name}.signalwire.com/api/fabric/resources/call_flows"

payload = {
    "title": "Welcome Call Flow",
    "relayml": {
        "sections": { "main": [{ "play": { "url": "https://cdn.signalwire.com/swml/audio.mp3" } }] },
        "version": "1.0.0"
    }
}
headers = {
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers, auth=("<project_id>", "<api_token>"))

print(response.json())
```

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

const options = {
  method: 'POST',
  headers: {
    Authorization: `Basic ${credentials}`,
    'Content-Type': 'application/json'
  },
  body: '{"title":"Welcome Call Flow","relayml":{"sections":{"main":[{"play":{"url":"https://cdn.signalwire.com/swml/audio.mp3"}}]},"version":"1.0.0"}}'
};

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

```go Welcome Call Flow
package main

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

func main() {

	url := "https://{your_space_name}.signalwire.com/api/fabric/resources/call_flows"

	payload := strings.NewReader("{\n  \"title\": \"Welcome Call Flow\",\n  \"relayml\": {\n    \"sections\": {\n      \"main\": [\n        {\n          \"play\": {\n            \"url\": \"https://cdn.signalwire.com/swml/audio.mp3\"\n          }\n        }\n      ]\n    },\n    \"version\": \"1.0.0\"\n  }\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.SetBasicAuth("<project_id>", "<api_token>")
	req.Header.Add("Content-Type", "application/json")

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

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

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

}
```

```ruby Welcome Call Flow
require 'uri'
require 'net/http'

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

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

request = Net::HTTP::Post.new(url)
request.basic_auth("<project_id>", "<api_token>")
request["Content-Type"] = 'application/json'
request.body = "{\n  \"title\": \"Welcome Call Flow\",\n  \"relayml\": {\n    \"sections\": {\n      \"main\": [\n        {\n          \"play\": {\n            \"url\": \"https://cdn.signalwire.com/swml/audio.mp3\"\n          }\n        }\n      ]\n    },\n    \"version\": \"1.0.0\"\n  }\n}"

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

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

HttpResponse<String> response = Unirest.post("https://{your_space_name}.signalwire.com/api/fabric/resources/call_flows")
  .basicAuth("<project_id>", "<api_token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"title\": \"Welcome Call Flow\",\n  \"relayml\": {\n    \"sections\": {\n      \"main\": [\n        {\n          \"play\": {\n            \"url\": \"https://cdn.signalwire.com/swml/audio.mp3\"\n          }\n        }\n      ]\n    },\n    \"version\": \"1.0.0\"\n  }\n}")
  .asString();
```

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

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://{your_space_name}.signalwire.com/api/fabric/resources/call_flows', [
  'body' => '{
  "title": "Welcome Call Flow",
  "relayml": {
    "sections": {
      "main": [
        {
          "play": {
            "url": "https://cdn.signalwire.com/swml/audio.mp3"
          }
        }
      ]
    },
    "version": "1.0.0"
  }
}',
  'headers' => [
    'Content-Type' => 'application/json',
  ],
    'auth' => ['<project_id>', '<api_token>'],
]);

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

```csharp Welcome Call Flow
using RestSharp;
using RestSharp.Authenticators;

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

request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"title\": \"Welcome Call Flow\",\n  \"relayml\": {\n    \"sections\": {\n      \"main\": [\n        {\n          \"play\": {\n            \"url\": \"https://cdn.signalwire.com/swml/audio.mp3\"\n          }\n        }\n      ]\n    },\n    \"version\": \"1.0.0\"\n  }\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift Welcome Call Flow
import Foundation

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

let headers = [
  "Authorization": "Basic \(credentials)",
  "Content-Type": "application/json"
]
let parameters = [
  "title": "Welcome Call Flow",
  "relayml": [
    "sections": ["main": [["play": ["url": "https://cdn.signalwire.com/swml/audio.mp3"]]]],
    "version": "1.0.0"
  ]
] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://{your_space_name}.signalwire.com/api/fabric/resources/call_flows")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

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()
```