Answer call

POST /calls/:call_control_id/actions/answer

Answer an incoming call. You must issue this command before executing subsequent commands on an incoming call.

Expected Webhooks:

call.answered
streaming.started, streaming.stopped or streaming.failed if stream_url was set

Request

Path Parameters

call_control_id stringrequired

Unique identifier and token for controlling the call

application/json

Body

required

Answer call request

billing_group_id uuid

Use this field to set the Billing Group ID for the call. Must be a valid and existing Billing Group ID.

client_state string

Use this field to add state to every subsequent webhook. It must be a valid Base-64 encoded string.

command_id string

Use this field to avoid duplicate commands. Telnyx will ignore any command with the same command_id for the same call_control_id.

custom_headers

object[]

Custom headers to be added to the SIP INVITE response.

Array [

name stringrequired

The name of the header to add.

value stringrequired

The value of the header.

]

Custom headers to be added to the SIP INVITE response.

preferred_codecs string

Possible values: [G722,PCMU,PCMA,G729,OPUS,VP8,H264]

The list of comma-separated codecs in a preferred order for the forked media to be received.

sip_headers

object[]

SIP headers to be added to the SIP INVITE response. Currently only User-to-User header is supported.

Array [

name stringrequired

Possible values: [User-to-User]

The name of the header to add.

value stringrequired

The value of the header.

]

SIP headers to be added to the SIP INVITE response. Currently only User-to-User header is supported.

sound_modifications

object

Use this field to modify sound effects, for example adjust the pitch.

pitch double

Set the pitch directly, value should be > 0, default 1 (lower = lower tone)

semitone double

Adjust the pitch in semitones, values should be between -14 and 14, default 0

octaves double

Adjust the pitch in octaves, values should be between -1 and 1, default 0

track string

Default value: outbound

The track to which the sound modifications will be applied. Accepted values are inbound or outbound

Use this field to modify sound effects, for example adjust the pitch.

stream_url string

The destination WebSocket address where the stream is going to be delivered.

stream_track string

Possible values: [inbound_track, outbound_track, both_tracks]

Default value: inbound_track

Specifies which track should be streamed.

send_silence_when_idle boolean

Generate silence RTP packets when no transmission available.

webhook_url string

Use this field to override the URL for which Telnyx will send subsequent webhooks to for this call.

webhook_url_method string

Possible values: [POST, GET]

Default value: POST

HTTP request type used for webhook_url.

transcription boolean

Enable transcription upon call answer. The default value is false.

transcription_config

object

transcription_engine string

Possible values: [A, B]

Default value: A

Engine to use for speech recognition. A - google, B - telnyx.

language

object

oneOf

string

Possible values: [af, sq, am, ar, hy, az, eu, bn, bs, bg, my, ca, yue, zh, hr, cs, da, nl, en, et, fil, fi, fr, gl, ka, de, el, gu, iw, hi, hu, is, id, it, ja, jv, kn, kk, km, ko, lo, lv, lt, mk, ms, ml, mr, mn, ne, no, fa, pl, pt, pa, ro, ru, rw, sr, si, sk, sl, ss, st, es, su, sw, sv, ta, te, th, tn, tr, ts, uk, ur, uz, ve, vi, xh, zu]

string

Possible values: [en, zh, de, es, ru, ko, fr, ja, pt, tr, pl, ca, nl, ar, sv, it, id, hi, fi, vi, he, uk, el, ms, cs, ro, da, hu, ta, no, th, ur, hr, bg, lt, la, mi, ml, cy, sk, te, fa, lv, bn, sr, az, sl, kn, et, mk, br, eu, is, hy, ne, mn, bs, kk, sq, sw, gl, mr, pa, si, km, sn, yo, so, af, oc, ka, be, tg, sd, gu, am, yi, lo, uz, fo, ht, ps, tk, nn, mt, sa, lb, my, bo, tl, mg, as, tt, haw, ln, ha, ba, jw, su, auto_detect]

interim_results boolean

Whether to send also interim results. If set to false, only final results will be sent. Applies to google engine only.

client_state string

Use this field to add state to every subsequent webhook. It must be a valid Base-64 encoded string.

transcription_tracks string

Default value: inbound

Indicates which leg of the call will be transcribed. Use inbound for the leg that requested the transcription, outbound for the other leg, and both for both legs of the call. Will default to inbound.

command_id string

Use this field to avoid duplicate commands. Telnyx will ignore any command with the same command_id for the same call_control_id.

Responses

200: Successful response upon making a call control command.

application/json

Schema

data

object

result string

{
  "data": {
    "result": "ok"
  }
}

default: Unexpected error

application/json

Schema

errors

Error[]

Array [

code integerrequired

title stringrequired

detail string

source

object

pointer json-pointer

JSON pointer (RFC6901) to the offending entity.

parameter string

Indicates which query parameter caused the error.

meta object

]

{
  "errors": [
    {
      "code": "string",
      "title": "string",
      "detail": "string",
      "source": {
        "pointer": "string",
        "parameter": "string"
      },
      "meta": {}
    }
  ]
}

Callbacks

Request samples

curl -L 'https://api.telnyx.com/v2/calls/:call_control_id/actions/answer' \
-H 'Content-Type: application/json' \
-H 'Accept: application/json' \
-H 'Authorization: Bearer <TOKEN>' \
-d '{
  "client_state": "aGF2ZSBhIG5pY2UgZGF5ID1d",
  "command_id": "891510ac-f3e4-11e8-af5b-de00688a4901",
  "webhook_url": "https://www.example.com/server-b/",
  "webhook_url_method": "POST",
  "send_silence_when_idle": true
}'

Response samples

{
  "data": {
    "result": "ok"
  }
}

{
  "errors": [
    {
      "code": "string",
      "title": "string",
      "detail": "string",
      "source": {
        "pointer": "string",
        "parameter": "string"
      },
      "meta": {}
    }
  ]
}

Answer call

Request​

Path Parameters

Body

Responses​

Callbacks​

Request

Responses

Callbacks