transfer

Transfer the execution of the script to a different SWML section, URL, or Relay application. Once the transfer is complete, the script will continue executing SWML from the new location.

Name	Type	Default	Description
transfer Required	object	-	An object that accepts the transfer parameters.

transfer Parameters

Name	Type	Default	Description
dest Required	string	-	Specifies where to transfer to. The value can be one of: "<section_name>" - section in the SWML document to jump to "relay:<relay application>" - relay application to notify (currently not implemented) "https://<URL>" - URL to fetch next document from. Sends HTTP POST Authentication can also be set in the url in the format of username:password@url.
params Optional	object	-	Named parameters to send to a section, URL, or application.

---

Valid Destination Values

The destination string can be one of:

• "section_name" - section in the current document to execute. (For example: execute: main)
• "relay:<relay application>" - relay application to notify (currently not implemented)
• "https://example.com/sub-swml.yaml" - URL pointing to the document to execute. An HTTP POST request will be sent to the URL. Authentication can also be set in the url in the format of username:password@url. The params object is passed, along with the variables and the Call object.

---

Examples

Basic transfer to a URL

YAML

version: 1.0.0
sections:
  main:
    - transfer:
        dest: "https://example.com/next"

JSON

{
  "version": "1.0.0",
  "sections": {
    "main": [
      {
        "transfer": {
          "dest": "https://example.com/next"
        }
      }
    ]
  }
}

Basic transfer to a section

YAML

version: 1.0.0
sections:
  main:
    - play:
        url: 'say:Transferring you to another section'
    - transfer:
        dest: subsection
    - play:
        url: 'say:Back!'
  subsection:
    - play:
        url: 'say:inside a subsection'

JSON

{
  "version": "1.0.0",
  "sections": {
    "main": [
      {
        "play": {
          "url": "say:Transferring you to another section"
        }
      },
      {
        "transfer": {
          "dest": "subsection"
        }
      },
      {
        "play": {
          "url": "say:Back!"
        }
      }
    ],
    "subsection": [
      {
        "play": {
          "url": "say:inside a subsection"
        }
      }
    ]
  }
}

Named parameter with sub-parameters

YAML

version: 1.0.0
sections:
  main:
    - transfer:
        - dest: "https://example.com/next"
        - params:
            - foo: "bar"

JSON

{
  "version": "1.0.0",
  "sections": {
    "main": [
      {
        "transfer": [
          {
            "dest": "https://example.com/next"
          },
          {
            "params": [
              {
                "foo": "bar"
              }
            ]
          }
        ]
      }
    ]
  }
}

Transfer to a SWML script hosted on a server

YAML

version: 1.0.0
sections:
  main:
    - prompt:
        play: >-
          say: Press 1 to be transfered to the Sales department, 2 for marketing
          department or anything else to listen to some music.
    - switch:
        variable: prompt_value
        case:
          '1':
            - transfer:
                dest: 'https://<YOUR_NGROK_UUID>.ngrok-free.app'
                params:
                  where: sales
          '2':
            - transfer:
                dest: 'https://<YOUR_NGROK_UUID>.ngrok-free.app'
                params:
                  where: marketing
    - play:
        url: 'https://cdn.signalwire.com/swml/April_Kisses.mp3'

JSON

{
  "version": "1.0.0",
  "sections": {
    "main": [
      {
        "prompt": {
          "play": "say: Press 1 to be transfered to the Sales department, 2 for marketing department or anything else to listen to some music."
        }
      },
      {
        "switch": {
          "variable": "prompt_value",
          "case": {
            "1": [
              {
                "transfer": {
                  "dest": "https://<YOUR_NGROK_UUID>.ngrok-free.app",
                  "params": {
                    "where": "sales"
                  }
                }
              }
            ],
            "2": [
              {
                "transfer": {
                  "dest": "https://<YOUR_NGROK_UUID>.ngrok-free.app",
                  "params": {
                    "where": "marketing"
                  }
                }
              }
            ]
          }
        }
      },
      {
        "play": {
          "url": "https://cdn.signalwire.com/swml/April_Kisses.mp3"
        }
      }
    ]
  }
}

A minimal server for this SWML script can be written as follows:

Python/Flask

from flask import Flask, request
from waitress import serve

app = Flask(__name__)

@app.route("/", methods=['POST'])
def swml():
    content = request.get_json(silent=True)
    print(content)
    return '''
version: 1.0.0
sections:
  main:
    - answer: {}
    - play:
        url: 'say: Welcome to the {} department.'
'''.format(content['params']['where'])

if __name__ == "__main__":
    serve(app, host='0.0.0.0', port=6000)

JavaScript/Express

const express = require("express");
const app = express();

app.use(express.json());

// note the POST method
app.post("/", (req, res) => {
  const data = req.body;
  console.log(data);
  res.send(`
version: 1.0.0
sections:
  main:
    - answer: {}
    - play:
        url: 'say: Welcome to the {} department.'
  `);
});

const port = 6000;
app.listen(port);

This server (running on localhost) can be made accessible to the wider web (and thus this SWML script) using forwarding tools like ngrok. You can follow our Testing webhooks with ngrok guide to learn how.

The server will be sent the payload in the following format:

{
  "call": {
    "call_id": "<call_id>",
    "node_id": "<node_id>",
    "segment_id": "<segment_id>",
    "call_state": "answered",
    "direction": "inbound",
    "type": "phone",
    "from": "<address>",
    "to": "<address>",
    "from_number": "<address>",
    "to_number": "<address>",
    "headers": [],
    "project_id": "<your Project UUID>",
    "space_id": "<your Space UUID>"
  },
  "vars": {
    "answer_result": "success",
    "prompt_result": "match_digits",
    "prompt_value_raw": "2",
    "prompt_value": "2"
  },
  "params": { "where": "marketing" }
}

The call object is described in detail in the introduction. All variables created within the SWML document are passed inside vars, and the params object contains the parameters defined in the params parameter of transfer.