> ## Documentation Index > Fetch the complete documentation index at: https://developers.telnyx.com/llms.txt > Use this file to discover all available pages before exploring further. # Recording start > Start recording the call. Recording will stop on call hang-up, or can be initiated via the Stop Recording command. **Expected Webhooks:** - `call.recording.saved` - `call.recording.transcription.saved` - `call.recording.error` ## OpenAPI ````yaml https://telnyx-openapi-ng.s3.us-east-1.amazonaws.com/call-control-commands/record-start.yml post /calls/{call_control_id}/actions/record_start openapi: 3.1.0 info: title: Telnyx Call Control - Record Start version: 2.0.0 description: API for starting call recording. contact: email: support@telnyx.com servers: - url: https://api.telnyx.com/v2 security: - bearerAuth: [] tags: - name: Command description: Call control command operations - name: Callbacks description: Webhook callbacks for call events paths: /calls/{call_control_id}/actions/record_start: post: tags: - Call Commands summary: Recording start description: > Start recording the call. Recording will stop on call hang-up, or can be initiated via the Stop Recording command. **Expected Webhooks:** - `call.recording.saved` - `call.recording.transcription.saved` - `call.recording.error` operationId: StartCallRecord parameters: - $ref: '#/components/parameters/CallControlId' requestBody: description: Start recording audio request required: true content: application/json: schema: $ref: '#/components/schemas/StartRecordingRequest' responses: '200': $ref: '#/components/responses/CallControlCommandResponse' '422': $ref: '#/components/responses/UnprocessableEntityResponse' default: $ref: '#/components/responses/call-control_GenericErrorResponse' x-codeSamples: - lang: JavaScript source: >- import Telnyx from 'telnyx'; const client = new Telnyx({ apiKey: process.env['TELNYX_API_KEY'], // This is the default and can be omitted }); const response = await client.calls.actions.startRecording('call_control_id', { channels: 'single', format: 'wav', }); console.log(response.data); - lang: Python source: |- import os from telnyx import Telnyx client = Telnyx( api_key=os.environ.get("TELNYX_API_KEY"), # This is the default and can be omitted ) response = client.calls.actions.start_recording( call_control_id="call_control_id", channels="single", format="wav", ) print(response.data) - lang: Go source: "package main\n\nimport (\n\t\"context\"\n\t\"fmt\"\n\n\t\"github.com/team-telnyx/telnyx-go\"\n\t\"github.com/team-telnyx/telnyx-go/option\"\n)\n\nfunc main() {\n\tclient := telnyx.NewClient(\n\t\toption.WithAPIKey(\"My API Key\"),\n\t)\n\tresponse, err := client.Calls.Actions.StartRecording(\n\t\tcontext.TODO(),\n\t\t\"call_control_id\",\n\t\ttelnyx.CallActionStartRecordingParams{\n\t\t\tChannels: telnyx.CallActionStartRecordingParamsChannelsSingle,\n\t\t\tFormat: telnyx.CallActionStartRecordingParamsFormatWav,\n\t\t},\n\t)\n\tif err != nil {\n\t\tpanic(err.Error())\n\t}\n\tfmt.Printf(\"%+v\\n\", response.Data)\n}\n" - lang: Java source: >- package com.telnyx.sdk.example; import com.telnyx.sdk.client.TelnyxClient; import com.telnyx.sdk.client.okhttp.TelnyxOkHttpClient; import com.telnyx.sdk.models.calls.actions.ActionStartRecordingParams; import com.telnyx.sdk.models.calls.actions.ActionStartRecordingResponse; public final class Main { private Main() {} public static void main(String[] args) { TelnyxClient client = TelnyxOkHttpClient.fromEnv(); ActionStartRecordingParams params = ActionStartRecordingParams.builder() .callControlId("call_control_id") .channels(ActionStartRecordingParams.Channels.SINGLE) .format(ActionStartRecordingParams.Format.WAV) .build(); ActionStartRecordingResponse response = client.calls().actions().startRecording(params); } } - lang: Ruby source: >- require "telnyx" telnyx = Telnyx::Client.new(api_key: "My API Key") response = telnyx.calls.actions.start_recording("call_control_id", channels: :single, format_: :wav) puts(response) - lang: CLI source: |- telnyx calls:actions start-recording \ --api-key 'My API Key' \ --call-control-id call_control_id \ --channels single \ --format wav components: parameters: CallControlId: name: call_control_id description: Unique identifier and token for controlling the call in: path required: true schema: type: string schemas: StartRecordingRequest: type: object title: Start Recording Request required: - format - channels properties: format: description: >- The audio file format used when storing the call recording. Can be either `mp3` or `wav`. type: string enum: - wav - mp3 example: mp3 channels: description: >- When `dual`, final audio file will be stereo recorded with the first leg on channel A, and the rest on channel B. enum: - single - dual type: string example: single client_state: description: >- Use this field to add state to every subsequent webhook. It must be a valid Base-64 encoded string. type: string example: aGF2ZSBhIG5pY2UgZGF5ID1d command_id: description: >- Use this field to avoid duplicate commands. Telnyx will ignore any command with the same `command_id` for the same `call_control_id`. type: string example: 891510ac-f3e4-11e8-af5b-de00688a4901 play_beep: description: If enabled, a beep sound will be played at the start of a recording. type: boolean example: true max_length: description: >- Defines the maximum length for the recording in seconds. The minimum value is 0. The maximum value is 14400. The default value is 0 (infinite) type: integer example: 100 default: 0 format: int32 timeout_secs: description: >- The number of seconds that Telnyx will wait for the recording to be stopped if silence is detected. The timer only starts when the speech is detected. Please note that call transcription is used to detect silence and the related charge will be applied. The minimum value is 0. The default value is 0 (infinite) type: integer example: 100 default: 0 format: int32 recording_track: description: >- The audio track to be recorded. Can be either `both`, `inbound` or `outbound`. If only single track is specified (`inbound`, `outbound`), `channels` configuration is ignored and it will be recorded as mono (single channel). type: string example: outbound default: both enum: - both - inbound - outbound trim: description: >- When set to `trim-silence`, silence will be removed from the beginning and end of the recording. enum: - trim-silence type: string example: trim-silence custom_file_name: description: >- The custom recording file name to be used instead of the default `call_leg_id`. Telnyx will still add a Unix timestamp suffix. type: string minLength: 1 maxLength: 40 example: my_recording_file_name transcription: description: Enable post recording transcription. The default value is false. type: boolean default: false example: true transcription_engine: description: >- Engine to use for speech recognition. `A` - `Google`, `B` - `Telnyx`, `deepgram/nova-3` - `Deepgram Nova-3`. Note: `deepgram/nova-3` supports only `en` and `en-{Region}` languages. type: string enum: - A - B - deepgram/nova-3 default: A example: A transcription_language: $ref: '#/components/schemas/TranscriptionLanguage' transcription_profanity_filter: description: Enables profanity_filter. Applies to `google` engine only. type: boolean default: false example: true transcription_speaker_diarization: description: Enables speaker diarization. Applies to `google` engine only. type: boolean default: false example: true transcription_min_speaker_count: description: >- Defines minimum number of speakers in the conversation. Applies to `google` engine only. type: integer example: 4 default: 2 format: int32 transcription_max_speaker_count: description: >- Defines maximum number of speakers in the conversation. Applies to `google` engine only. type: integer example: 4 default: 6 format: int32 example: format: wav channels: single client_state: aGF2ZSBhIG5pY2UgZGF5ID1d command_id: 891510ac-f3e4-11e8-af5b-de00688a4901 play_beep: true max_length: 0 timeout_secs: 0 transcription: true transcription_engine: B transcription_language: en TranscriptionLanguage: title: Transcription Language type: string description: >- Language code for transcription. Note: Not all languages are supported by all transcription engines (google, telnyx, deepgram). See engine-specific documentation for supported values. example: en-US default: en-US enum: - af - af-ZA - am - am-ET - ar - ar-AE - ar-BH - ar-DZ - ar-EG - ar-IL - ar-IQ - ar-JO - ar-KW - ar-LB - ar-MA - ar-MR - ar-OM - ar-PS - ar-QA - ar-SA - ar-TN - ar-YE - as - auto_detect - az - az-AZ - ba - be - bg - bg-BG - bn - bn-BD - bn-IN - bo - br - bs - bs-BA - ca - ca-ES - cs - cs-CZ - cy - da - da-DK - de - de-AT - de-CH - de-DE - el - el-GR - en - en-AU - en-CA - en-GB - en-GH - en-HK - en-IE - en-IN - en-KE - en-NG - en-NZ - en-PH - en-PK - en-SG - en-TZ - en-US - en-ZA - es - es-419 - es-AR - es-BO - es-CL - es-CO - es-CR - es-DO - es-EC - es-ES - es-GT - es-HN - es-MX - es-NI - es-PA - es-PE - es-PR - es-PY - es-SV - es-US - es-UY - es-VE - et - et-EE - eu - eu-ES - fa - fa-IR - fi - fi-FI - fil-PH - fo - fr - fr-BE - fr-CA - fr-CH - fr-FR - gl - gl-ES - gu - gu-IN - ha - haw - he - hi - hi-IN - hr - hr-HR - ht - hu - hu-HU - hy - hy-AM - id - id-ID - is - is-IS - it - it-CH - it-IT - iw-IL - ja - ja-JP - jv-ID - jw - ka - ka-GE - kk - kk-KZ - km - km-KH - kn - kn-IN - ko - ko-KR - la - lb - ln - lo - lo-LA - lt - lt-LT - lv - lv-LV - mg - mi - mk - mk-MK - ml - ml-IN - mn - mn-MN - mr - mr-IN - ms - ms-MY - mt - my - my-MM - ne - ne-NP - nl - nl-BE - nl-NL - nn - 'no' - no-NO - oc - pa - pa-Guru-IN - pl - pl-PL - ps - pt - pt-BR - pt-PT - ro - ro-RO - ru - ru-RU - rw-RW - sa - sd - si - si-LK - sk - sk-SK - sl - sl-SI - sn - so - sq - sq-AL - sr - sr-RS - ss-latn-za - st-ZA - su - su-ID - sv - sv-SE - sw - sw-KE - sw-TZ - ta - ta-IN - ta-LK - ta-MY - ta-SG - te - te-IN - tg - th - th-TH - tk - tl - tn-latn-za - tr - tr-TR - ts-ZA - tt - uk - uk-UA - ur - ur-IN - ur-PK - uz - uz-UZ - ve-ZA - vi - vi-VN - xh-ZA - yi - yo - yue-Hant-HK - zh - zh-TW - zu-ZA CallControlCommandResult: type: object title: Call Control Command Result example: result: ok properties: result: type: string example: ok call-control_Errors: properties: errors: type: array items: $ref: '#/components/schemas/call-control_Error' call-control_Error: required: - code - title properties: code: type: string format: integer title: type: string detail: type: string source: type: object properties: pointer: description: JSON pointer (RFC6901) to the offending entity. type: string format: json-pointer parameter: description: Indicates which query parameter caused the error. type: string meta: type: object responses: CallControlCommandResponse: description: Successful response upon making a call control command. content: application/json: schema: type: object title: Call Control Command Response properties: data: $ref: '#/components/schemas/CallControlCommandResult' UnprocessableEntityResponse: description: >- Unprocessable entity. The request was well-formed but could not be processed due to semantic errors. This includes validation errors, invalid parameter values, call state errors, conference errors, queue errors, recording/transcription errors, and business logic violations. content: application/json: schema: $ref: '#/components/schemas/call-control_Errors' examples: missing_required_parameter: summary: Missing required parameter value: errors: - code: '10004' title: Missing required parameter detail: The 'to' parameter is required and cannot be blank. source: pointer: /to invalid_call_control_id: summary: Invalid call control ID value: errors: - code: '90015' title: Invalid Call Control ID detail: The call_control_id provided was not valid. source: pointer: /call_control_id call_already_ended: summary: Call has already ended value: errors: - code: '90018' title: Call has already ended detail: This call is no longer active and can't receive commands. call_not_answered: summary: Call not answered yet value: errors: - code: '90034' title: Call not answered yet detail: >- This call can't receive this command because it has not been answered yet. cannot_record_before_audio_started: summary: Cannot record before audio started value: errors: - code: '90020' title: Call recording triggered before audio started detail: >- Call recording cannot be started until audio has commenced on the call. transcription_already_active: summary: Transcription already active value: errors: - code: '90054' title: Call transcription is already in progress detail: Call transcription can not be started more than once. ai_assistant_already_active: summary: AI Assistant already active value: errors: - code: '90061' title: AI Assistant is already in progress detail: AI Assistant cannot be started more than once. conference_already_ended: summary: Conference has already ended value: errors: - code: '90019' title: Conference has already ended detail: >- This conference is no longer active and can't receive commands. conference_name_conflict: summary: Conference name conflict value: errors: - code: '90033' title: Unable to execute command detail: Conference with given name already exists and it's active. max_participants_reached: summary: Maximum participants reached value: errors: - code: '90032' title: Maximum number of participants reached detail: >- The maximum allowed value of `max_participants` has been reached at 100. queue_full: summary: Queue is full value: errors: - code: '90036' title: Queue full detail: The 'support' queue is full and can't accept more calls. call_already_in_queue: summary: Call already in queue value: errors: - code: '90038' title: Call already in queue detail: Call can't be added to a queue it's already in. invalid_connection_id: summary: Invalid connection ID value: errors: - code: '10015' title: Invalid value for connection_id (Call Control App ID) detail: >- The requested connection_id (Call Control App ID) is either invalid or does not exist. Only Call Control Apps with valid webhook URL are accepted. source: pointer: /connection_id invalid_phone_number_format: summary: Invalid phone number format value: errors: - code: '10016' title: Phone number must be in +E164 format detail: The 'to' parameter must be in E164 format. source: pointer: /to srtp_not_supported_for_pstn: summary: SRTP not supported for PSTN calls value: errors: - source: pointer: /media_encryption title: Media encryption not supported for PSTN calls detail: SRTP media encryption is not supported for PSTN calls. code: '10011' fork_not_found: summary: Call is not forked value: errors: - code: '90031' title: Call is not currently forked detail: >- Can't stop forking, because the call isn't currently forked. media_streaming_used: summary: Media streaming in use value: errors: - code: '90045' title: Media Streaming is used detail: This command can't be issued when media streaming is used. invalid_enumerated_value: summary: Invalid enumerated value value: errors: - code: '10032' title: Invalid enumerated value detail: 'The value must be one of: dual, single.' source: pointer: /record_channels value_outside_range: summary: Value outside of range value: errors: - code: '10033' title: Value outside of range detail: The value is outside of allowed range 1 to 5000 source: pointer: /max_participants call-control_GenericErrorResponse: description: Unexpected error content: application/json: schema: $ref: '#/components/schemas/call-control_Errors' securitySchemes: bearerAuth: scheme: bearer type: http ````