record_call

Record call in the background. Unlike the record method, the record_call method will start the recording and continue executing the SWML script while allowing the recording to happen in the background. To stop call recordings started with record_call, use the stop_record_call method.

Properties

objectRequired

An object that accepts the following properties.

record_call.control_id

stringDefaults to Auto-generated, saved to record_control_id variable

Identifier for this recording, to use with stop_record_call

record_call.stereo

booleanDefaults to false

Whether to record in stereo mode

record_call.format

stringDefaults to wav

Format ("wav", "mp3", or "mp4")

record_call.direction

stringDefaults to both

Direction of the audio to record: "speak" for what party says, "listen" for what party hears, "both" for what the party hears and says

record_call.terminators

string

String of digits that will stop the recording when pressed. Default is empty (no terminators).

record_call.beep

booleanDefaults to false

Whether to play a beep before recording

record_call.input_sensitivity

numberDefaults to 44.0

How sensitive the recording voice activity detector is to background noise? A larger value is more sensitive. Allowed values from 0.0 to 100.0.

record_call.initial_timeout

numberDefaults to 0

How long, in seconds, to wait for speech to start?

record_call.end_silence_timeout

numberDefaults to 0

How much silence, in seconds, will end the recording?

record_call.max_length

number

Maximum length of the recording in seconds.

record_call.status_url

string

HTTP or HTTPS URL to deliver record status events. Learn more about status callbacks.

Variables

Set by the method:

record_call_url: (out) the URL of the newly started recording.
record_call_result: (out) success | failed.
record_control_id: (out) control ID of this recording.

StatusCallbacks

Status callbacks are advisory

Status callbacks are asynchronous, best-effort HTTP notifications: delivery can be delayed or fail silently — if your server is unreachable, the callback simply never arrives. Don’t gate time-critical or business-critical actions solely on receiving one. Confirm state via the REST API before acting, or use a transport with visible failure modes — see Status callback reliability.

A POST request will be sent to status_url with a JSON payload like the following:

event_type

string

The type of event. Always calling.call.record for this method.

event_channel

string

The channel for the event, includes the SWML session ID.

timestamp

number

Unix timestamp (float) when the event was generated.

project_id

string

The project ID associated with the call.

space_id

string

The Space ID associated with the call.

params

object

An object containing recording-specific parameters.

params.call_id

string

The call ID.

params.node_id

string

The node handling the call.

params.control_id

string

The control ID for this record operation.

params.state

string

The current recording state. Valid values: recording, paused, finished, no_input, error.

params.url

string

URL of the recorded media on files.signalwire.com. Present from the recording state onward.

params.recording_id

string

ID of the recording, matching the id returned by the Recordings API.

params.duration

integer

Recording duration in seconds. Present when the recording ends.

params.size

integer

Recording file size in bytes. Present when the recording ends.

params.start_time

number

Unix timestamp (float) when the recording started. Present when the recording ends.

params.end_time

number

Unix timestamp (float) when the recording ended. Present when the recording ends.

params.first_frame_time

number

Unix timestamp (float) of the first recorded audio frame. Present when state is finished.

params.pause_behavior

string

How paused recording handles audio. Only present when state is paused. Valid values: silence, skip.

params.segment_id

string

The call segment the recording belongs to.

params.record

object

The configuration the recording ran with.

record.audio.format

string

Recording format. Valid values: wav, mp3, mp4.

record.audio.direction

string

Direction of the audio recorded. Valid values: speak, listen, both.

record.audio.stereo

boolean

Whether the recording was made in stereo mode.

Raw JSON example

{
  "event_type": "calling.call.record",
  "event_channel": "swml:xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "timestamp": 1640000000.123,
  "project_id": "xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "space_id": "xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
  "params": {
    "call_id": "xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "node_id": "xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "control_id": "xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "state": "finished",
    "url": "https://files.signalwire.com/<SPACE_ID>/<PROJECT_ID>/recordings/<RECORDING_ID>.wav",
    "recording_id": "xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "duration": 18,
    "size": 298284,
    "start_time": 1789651036.217461,
    "end_time": 1789651055.516839,
    "first_frame_time": 1789651036.219012,
    "segment_id": "xxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx",
    "record": {
      "audio": {
        "format": "wav",
        "direction": "both",
        "stereo": false
      }
    }
  }
}

Examples

Start an MP3 recording of the call

version: 1.0.0
sections:
  main:
    - record_call:
        format: mp3

Record and play back

Record both sides of the conversation:

version: 1.0.0
sections:
  main:
    - record_call:
        beep: true
        terminators: '#'
    - play:
        urls:
          - 'say:Leave your message now'
          - 'silence:10'
    - stop_record_call: {}
    - play:
        urls:
          - 'say:Playing back'
          - '${record_call_url}'

Record only the speaker’s side

version: 1.0.0
sections:
  main:
    - record_call:
        beep: true
        direction: speak
    - play:
        urls:
          - 'say:Leave your message now'
          - 'silence:10'
    - stop_record_call: {}
    - play:
        urls:
          - 'say:Playing back'
          - '${record_call_url}'