Update Speech Engine

PATCH https://api.elevenlabs.io/v1/speech-engine/ Content-Type: application/json

Update a Speech Engine resource (partial update)

Reference: https://elevenlabs.io/docs/api-reference/speech-engine/update

• https://api.elevenlabs.io (Production, default)
• https://api.us.elevenlabs.io (Production US)
• https://api.eu.residency.elevenlabs.io (Production EU)
• https://api.in.residency.elevenlabs.io (Production India)
• https://api.sg.residency.elevenlabs.io (Production Singapore)

• speech_engine_id (string, required) — The speech engine ID (accepts seng_ or agent_ prefix)

This endpoint expects an UpdateSpeechEngineRequest.

• name (string, optional, nullable)
• speech_engine (SpeechEngineConfig, optional, nullable)
• asr (ASRConversationalConfig, optional, nullable)
• tts (TTSConversationalConfig-Input, optional, nullable)
• turn (BaseTurnConfig, optional, nullable)
• vad (VADConfig, optional, nullable)
• conversation (ConversationConfig-Input, optional, nullable)
• privacy (PrivacyConfig-Input, optional, nullable)
• call_limits (AgentCallLimits, optional, nullable)
• language (string, optional, nullable)
• cascade_timeout_seconds (double, optional, nullable) — Time in seconds to wait for the upstream speech engine endpoint to respond before the attempt is abandoned and retried. Must be between 2 and 15 seconds.
• tags (list of string, optional, nullable)
• overrides (SpeechEngineConversationInitiationClientDataConfig, optional, nullable)

Successful Response

• speech_engine_id (string, required) — The speech engine resource ID
• name (string, required) — Human-readable name for the speech engine
• speech_engine (SpeechEngineConfig, required) — WebSocket connection settings for the upstream transcript server
• asr (ASRConversationalConfig, required) — Automatic speech recognition configuration
• tts (TTSConversationalConfig-Output, required) — Text-to-speech output configuration
• turn (BaseTurnConfig, required) — Turn detection configuration
• vad (VADConfig, required) — Configuration for voice activity detection
• conversation (ConversationConfig-Output, required) — Conversation-level settings including client events and duration limits
• privacy (PrivacyConfig-Output, required) — Privacy settings controlling recording, retention, and PII handling
• call_limits (AgentCallLimits, required) — Concurrency and daily conversation limits for this speech engine
• language (string, required) — ISO language code used by the speech engine (e.g. 'en')
• cascade_timeout_seconds (double, required) — Time in seconds to wait for the upstream speech engine endpoint to respond before the attempt is abandoned and retried. Must be between 2 and 15 seconds.
• tags (list of string, required) — Arbitrary tags for categorization and filtering
• overrides (SpeechEngineConversationInitiationClientDataConfig, required) — Override settings the client may set during conversation initiation
• metadata (AgentMetadataDBModel, required) — Creation and update timestamps with source information
• access_info (ResourceAccessInfo, optional, nullable) — The access information of the speech engine for the user

Validation Error

• detail (list of ValidationError, optional)

• ws_url (string, required) — The WebSocket URL for the transcript server
• request_headers (map from string to SpeechEngineConfigRequestHeaders, optional) — Headers to include in the WebSocket connection request

• quality (enum, optional, default: high) — The quality of the transcription
  • Allowed values: high
• provider (enum, optional, default: scribe_realtime) — The provider of the transcription service
  • Allowed values: elevenlabs, scribe_realtime
• user_input_audio_format (enum, optional, default: pcm_16000) — The format of the audio to be transcribed
  • Allowed values: pcm_8000, pcm_16000, pcm_22050, pcm_24000, pcm_44100, pcm_48000, ulaw_8000
• keywords (list of string, optional) — Keywords to boost prediction probability for

• model_id (enum, optional, default: eleven_flash_v2) — The model to use for TTS
  • Allowed values: eleven_turbo_v2, eleven_turbo_v2_5, eleven_flash_v2, eleven_flash_v2_5, eleven_multilingual_v2, eleven_v3_conversational
• voice_id (string, optional, default: cjVigY5qzO86Huf0OWal) — The voice ID to use for TTS
• supported_voices (list of SupportedVoice, optional) — Additional supported voices for the agent
• expressive_mode (boolean, optional, default: true) — When enabled, applies expressive audio tags prompt. Automatically disabled for non-v3 models.
• suggested_audio_tags (list of SuggestedAudioTag, optional) — Suggested audio tags to boost expressive speech (for eleven_v3 and eleven_v3_conversational models). The agent can still use other tags not listed here.
• agent_output_audio_format (enum, optional, default: pcm_16000) — The audio format to use for TTS
  • Allowed values: pcm_8000, pcm_16000, pcm_22050, pcm_24000, pcm_44100, pcm_48000, ulaw_8000
• stability (double, optional, default: 0.5) — The stability of generated speech
• speed (double, optional, default: 1) — The speed of generated speech
• similarity_boost (double, optional, default: 0.8) — The similarity boost for generated speech
• text_normalisation_type (enum, optional, default: system_prompt) — Method for converting numbers to words before converting text to speech. If set to SYSTEM_PROMPT, the system prompt will be updated to include normalization instructions. If set to ELEVENLABS, the text will be normalized after generation, incurring slight additional latency.
  • Allowed values: system_prompt, elevenlabs
• pronunciation_dictionary_locators (list of PydanticPronunciationDictionaryVersionLocator, optional) — The pronunciation dictionary locators
• enable_phoneme_tags (boolean, optional, default: true) — Opt-in to SSML phoneme tag handling for V3 models. When enabled, phoneme tags (inline and from pronunciation dictionaries) are parsed into inline IPA before being sent to the model.
• audio_effects (EffectsSpec-Input, optional, nullable) — Optional TTS effects spec: filter preset, distance (proximity EQ), and environment (convolution reverb).
• optimize_streaming_latency (enum, optional, deprecated) — Deprecated: this field is a no-op and is ignored.
  • Allowed values: 0, 1, 2, 3, 4

• turn_timeout (double, optional, default: 7) — Maximum wait time for the user's reply before re-engaging the user
• initial_wait_time (double, optional, nullable) — How long the agent will wait for the user to start the conversation if the first message is empty. If not set, uses the regular turn_timeout.
• silence_end_call_timeout (double, optional, default: -1) — Maximum wait time since the user last spoke before terminating the call
• turn_eagerness (enum, optional, default: normal) — Controls how eager the agent is to respond. Low = less eager (waits longer), Standard = default eagerness, High = more eager (responds sooner)
  • Allowed values: patient, normal, eager
• spelling_patience (enum, optional, default: auto) — Controls if the agent should be more patient when user is spelling numbers and named entities. Auto = model based, Off = never wait extra
  • Allowed values: auto, off
• speculative_turn (boolean, optional, default: false) — When enabled, starts generating LLM responses during silence before full turn confidence is reached, reducing perceived latency. May increase LLM costs.
• retranscribe_on_turn_timeout (boolean, optional, default: false) — When enabled, if VAD detects no speech, attempts to re-transcribe accumulated audio at turn timeout. Disables silence discount billing for affected turns.
• turn_model (enum, optional, default: turn_v3) — Version of the turn detection model to use.
  • Allowed values: turn_v2, turn_v3
• interruption_ignore_terms (list of string, optional) — List of terms that should not trigger an interruption when spoken by the user (e.g. 'gotcha', 'understood'). Uses case-insensitive exact matching.
• interruption_ignore_term_languages (list of string, optional) — Language codes for which preset ignore-term categories have been activated. Stored explicitly so display is not inferred from term overlap.
• merge_with_default_ignore_terms (boolean, optional, default: false) — When enabled, the curated default terms for interruption_ignore_term_languages are used in addition to interruption_ignore_terms.
• transcribe_on_disabled_interruptions (boolean, optional, default: false) — When interruptions are disabled, still transcribe what the user says so it can carry into the next turn. When off, user speech during a non-interruptible turn is ignored and won't trigger a turn.

• text_only (boolean, optional, default: false) — If enabled audio will not be processed and only text will be used, use to avoid audio pricing.
• max_duration_seconds (integer, optional, default: 600) — The maximum duration of a conversation in seconds
• client_events (list of enum, optional) — The events that will be sent to the client
  • Allowed values: conversation_initiation_metadata, asr_initiation_metadata, ping, audio, interruption, user_transcript, tentative_user_transcript, agent_response, agent_response_correction, client_tool_call, mcp_tool_call, mcp_connection_status, agent_tool_request, agent_tool_response, agent_tool_response_full_payload, agent_response_metadata, vad_score, agent_chat_response_part, client_error, guardrail_triggered, dtmf_request, agent_response_complete, context_usage, internal_turn_probability, internal_tentative_agent_response
• file_input (FileInputConfig, optional) — Configuration for file input (image/PDF uploads) during conversations.
• monitoring_enabled (boolean, optional, default: false) — Enable real-time monitoring of conversations via WebSocket
• monitoring_events (list of enum, optional) — The events that will be sent to monitoring connections.
  • Allowed values: conversation_initiation_metadata, asr_initiation_metadata, ping, audio, interruption, user_transcript, tentative_user_transcript, agent_response, agent_response_correction, client_tool_call, mcp_tool_call, mcp_connection_status, agent_tool_request, agent_tool_response, agent_tool_response_full_payload, agent_response_metadata, vad_score, agent_chat_response_part, client_error, guardrail_triggered, dtmf_request, agent_response_complete, context_usage, internal_turn_probability, internal_tentative_agent_response
• dtmf_input_settings (DTMFInputConfig, optional, nullable) — Configure DTMF (keypad) input collection during phone calls
• background_sound (BackgroundSoundConfig, optional) — Configuration for background sound during conversations.
• source_attribution (boolean, optional, default: false) — When enabled and knowledge base content is present, the LLM is instructed to report which sources it used.

• record_voice (boolean, optional, default: true) — Whether to record the conversation
• retention_days (integer, optional, default: -1) — The number of days to retain the conversation. -1 indicates there is no retention limit
• delete_transcript_and_pii (boolean, optional, default: false) — Whether to delete the transcript and PII
• delete_audio (boolean, optional, default: false) — Whether to delete the audio
• apply_to_existing_conversations (boolean, optional, default: false) — Whether to apply the privacy settings to existing conversations
• zero_retention_mode (boolean, optional, default: false) — Whether to enable zero retention mode - no PII data is stored
• conversation_history_redaction (ConversationHistoryRedactionConfig, optional) — Config for PII redaction in the conversation history

• agent_concurrency_limit (integer, optional, default: -1) — The maximum number of concurrent conversations. -1 indicates that there is no maximum
• daily_limit (integer, optional, default: 100000) — The maximum number of conversations per day
• bursting_enabled (boolean, optional, default: true) — Whether to enable bursting. If true, exceeding workspace concurrency limit will be allowed up to 3 times the limit. Calls will be charged at double rate when exceeding the limit.

• first_message (boolean, optional, default: false) — Whether the first message can be overridden by the client

• model_id (enum, optional, default: eleven_flash_v2) — The model to use for TTS
  • Allowed values: eleven_turbo_v2, eleven_turbo_v2_5, eleven_flash_v2, eleven_flash_v2_5, eleven_multilingual_v2, eleven_v3_conversational
• voice_id (string, optional, default: cjVigY5qzO86Huf0OWal) — The voice ID to use for TTS
• supported_voices (list of SupportedVoice, optional) — Additional supported voices for the agent
• expressive_mode (boolean, optional, default: true) — When enabled, applies expressive audio tags prompt. Automatically disabled for non-v3 models.
• suggested_audio_tags (list of SuggestedAudioTag, optional) — Suggested audio tags to boost expressive speech (for eleven_v3 and eleven_v3_conversational models). The agent can still use other tags not listed here.
• agent_output_audio_format (enum, optional, default: pcm_16000) — The audio format to use for TTS
  • Allowed values: pcm_8000, pcm_16000, pcm_22050, pcm_24000, pcm_44100, pcm_48000, ulaw_8000
• stability (double, optional, default: 0.5) — The stability of generated speech
• speed (double, optional, default: 1) — The speed of generated speech
• similarity_boost (double, optional, default: 0.8) — The similarity boost for generated speech
• text_normalisation_type (enum, optional, default: system_prompt) — Method for converting numbers to words before converting text to speech. If set to SYSTEM_PROMPT, the system prompt will be updated to include normalization instructions. If set to ELEVENLABS, the text will be normalized after generation, incurring slight additional latency.
  • Allowed values: system_prompt, elevenlabs
• pronunciation_dictionary_locators (list of PydanticPronunciationDictionaryVersionLocator, optional) — The pronunciation dictionary locators
• enable_phoneme_tags (boolean, optional, default: true) — Opt-in to SSML phoneme tag handling for V3 models. When enabled, phoneme tags (inline and from pronunciation dictionaries) are parsed into inline IPA before being sent to the model.
• audio_effects (EffectsSpec-Output, optional, nullable) — Optional TTS effects spec: filter preset, distance (proximity EQ), and environment (convolution reverb).
• optimize_streaming_latency (enum, optional, deprecated) — Deprecated: this field is a no-op and is ignored.
  • Allowed values: 0, 1, 2, 3, 4

• text_only (boolean, optional, default: false) — If enabled audio will not be processed and only text will be used, use to avoid audio pricing.
• max_duration_seconds (integer, optional, default: 600) — The maximum duration of a conversation in seconds
• client_events (list of enum, optional) — The events that will be sent to the client
  • Allowed values: conversation_initiation_metadata, asr_initiation_metadata, ping, audio, interruption, user_transcript, tentative_user_transcript, agent_response, agent_response_correction, client_tool_call, mcp_tool_call, mcp_connection_status, agent_tool_request, agent_tool_response, agent_tool_response_full_payload, agent_response_metadata, vad_score, agent_chat_response_part, client_error, guardrail_triggered, dtmf_request, agent_response_complete, context_usage, internal_turn_probability, internal_tentative_agent_response
• file_input (FileInputConfig, optional) — Configuration for file input (image/PDF uploads) during conversations.
• monitoring_enabled (boolean, optional, default: false) — Enable real-time monitoring of conversations via WebSocket
• monitoring_events (list of enum, optional) — The events that will be sent to monitoring connections.
  • Allowed values: conversation_initiation_metadata, asr_initiation_metadata, ping, audio, interruption, user_transcript, tentative_user_transcript, agent_response, agent_response_correction, client_tool_call, mcp_tool_call, mcp_connection_status, agent_tool_request, agent_tool_response, agent_tool_response_full_payload, agent_response_metadata, vad_score, agent_chat_response_part, client_error, guardrail_triggered, dtmf_request, agent_response_complete, context_usage, internal_turn_probability, internal_tentative_agent_response
• dtmf_input_settings (DTMFInputConfig, optional, nullable) — Configure DTMF (keypad) input collection during phone calls
• background_sound (BackgroundSoundConfig, optional) — Configuration for background sound during conversations.
• source_attribution (boolean, optional, default: false) — When enabled and knowledge base content is present, the LLM is instructed to report which sources it used.

• record_voice (boolean, optional, default: true) — Whether to record the conversation
• retention_days (integer, optional, default: -1) — The number of days to retain the conversation. -1 indicates there is no retention limit
• delete_transcript_and_pii (boolean, optional, default: false) — Whether to delete the transcript and PII
• delete_audio (boolean, optional, default: false) — Whether to delete the audio
• apply_to_existing_conversations (boolean, optional, default: false) — Whether to apply the privacy settings to existing conversations
• zero_retention_mode (boolean, optional, default: false) — Whether to enable zero retention mode - no PII data is stored
• conversation_history_redaction (ConversationHistoryRedactionConfig, optional) — Config for PII redaction in the conversation history

• created_at_unix_secs (integer, required)
• updated_at_unix_secs (integer, required)
• created_from (enum, optional, default: unknown)
  • Allowed values: cli, ui, api, template, unknown
• last_updated_from (enum, optional, default: unknown)
  • Allowed values: cli, ui, api, template, unknown

• is_creator (boolean, required) — Whether the user making the request is the creator of the agent
• creator_name (string, required) — Name of the agent's creator
• creator_email (string, required) — Email of the agent's creator
• role (enum, required) — The role of the user making the request
  • Allowed values: admin, editor, commenter, viewer
• anonymous_access_level_override (enum, optional, nullable) — The access level for anonymous users. If None, the resource is not shared publicly.
  • Allowed values: admin, editor, commenter, viewer
• access_source (enum, optional, nullable) — Why the requesting user has access to this resource. 'creator' = caller is the owner. 'explicit' = caller (or one of their workspace groups) is listed in role_to_group_ids beyond the workspace-wide everyone group. 'workspace_default' = the workspace-wide everyone group is listed in role_to_group_ids (every non-anon workspace member, including admins, sees this resource). 'workspace_admin' = caller is a workspace admin and the admin seat is the only path to access; reserved for docs nobody else can see. Lets the UI disclose why an admin-bypass viewer sees a doc that wasn't explicitly shared with them.
  • Allowed values: creator, explicit, workspace_admin, workspace_default

• loc (list of ValidationErrorLocItems, required)
• msg (string, required)
• type (string, required)

• label (string, required)
• voice_id (string, required)
• description (string, optional, nullable)
• language (string, optional, nullable)
• model_family (enum, optional, nullable)
  • Allowed values: turbo, flash, multilingual, v3_conversational
• optimize_streaming_latency (enum, optional, nullable)
  • Allowed values: 0, 1, 2, 3, 4
• stability (double, optional, nullable)
• speed (double, optional, nullable)
• similarity_boost (double, optional, nullable)

• tag (string, required) — Audio tag to use (for best performance, 1-2 words, e.g., 'happy', 'excited')
• description (string, optional, nullable) — Optional description of when to use this tag

A locator for other documents to be able to reference a specific dictionary and it's version. This is a pydantic version of PronunciationDictionaryVersionLocatorDBModel. Required to ensure compat with the rest of the agent data models.

• pronunciation_dictionary_id (string, required) — The ID of the pronunciation dictionary
• version_id (string, required, nullable) — The ID of the version of the pronunciation dictionary

Filter preset, distance (proximity EQ), and environment (convolution reverb).

• filter_preset_id (string, optional, nullable)
• distance (double, optional, default: 0)
• environment_id (string, optional, nullable)
• background_noise_id (string, optional, nullable)
• send_level (double, optional, default: 1)
• seed (integer, optional, nullable)

• enabled (boolean, optional, default: true) — When enabled, users may attach images or PDFs in chat when the LLM supports multimodal input.
• max_files_in_memory (integer, optional, default: 10) — Number of most-recent files kept in memory during a conversation. Older files are summarized and their bytes freed.
• max_files_per_conversation (integer, optional, default: 10) — Total files a user can upload in one conversation. Uploads are billed per file. Use -1 for no limit, or a value >= max_files_in_memory.

Configuration for DTMF (keypad) input collection during phone calls.

• dtmf_input_timeout (double, optional, default: 2) — Timeout in seconds to wait for additional DTMF digits
• hash_terminator (boolean, optional, default: true) — If true, pressing # immediately completes DTMF input
• redact_input (boolean, optional, default: false) — If true, replace the caller's DTMF (keypad) entries with a redaction marker in the transcript, conversation log and analysis. Digits the agent repeats back or passes to a tool are not affected.

• source_type (enum, optional, nullable) — The type of background sound source.
  • Allowed values: preset
• source_id (enum, optional, nullable) — Identifier for the sound source.
  • Allowed values: office2, office1, restaurant, city, typing, elevator1, elevator2, elevator3, elevator4
• volume (double, optional, default: 0.15) — Volume level for background sound (0.01 to 1.0).
• crossfade_loop (boolean, optional, default: true) — Apply a crossfade at the loop boundary to avoid audible pops when the sound loops.

• enabled (boolean, optional, default: false) — Whether conversation history redaction is enabled
• entities (list of enum, optional) — The entities to redact from the conversation transcript, audio and analysis. Use top-level types like 'name', 'email_address', or dot notation for specific subtypes like 'name.full_name'.
  • Allowed values: name, name.name_given, name.name_family, name.name_other, email_address, contact_number, dob, age, religious_belief, political_opinion, sexual_orientation, ethnicity_race, marital_status, occupation, physical_attribute, language, username, password, url, organization, financial_id, financial_id.payment_card, financial_id.payment_card.payment_card_number, financial_id.payment_card.payment_card_expiration_date, financial_id.payment_card.payment_card_cvv, financial_id.bank_account, financial_id.bank_account.bank_account_number, financial_id.bank_account.bank_routing_number, financial_id.bank_account.swift_bic_code, financial_id.financial_id_other, location, location.location_address, location.location_city, location.location_postal_code, location.location_coordinate, location.location_state, location.location_country, location.location_other, date, date_interval, unique_id, unique_id.government_issued_id, unique_id.account_number, unique_id.vehicle_id, unique_id.healthcare_number, unique_id.healthcare_number.medical_record_number, unique_id.healthcare_number.health_plan_beneficiary_number, unique_id.device_id, unique_id.unique_id_other, medical, medical.medical_condition, medical.medication, medical.medical_procedure, medical.medical_measurement, medical.medical_other

Filter preset, distance (proximity EQ), and environment (convolution reverb).

• filter_preset_id (string, required, nullable)
• distance (double, required, default: 0)
• environment_id (string, required, nullable)
• background_noise_id (string, required, nullable)
• send_level (double, required, default: 1)
• seed (integer, required, nullable)

Used to reference a secret from the agent's secret store.

• secret_id (string, required)

Used to reference a dynamic variable.

• variable_name (string, required)

Request

{}

Response

{
  "speech_engine_id": "seng_3701k3ttaq12ewp8b7qv5rfyszkz",
  "name": "My Speech Engine",
  "speech_engine": {
    "ws_url": "wss://example.com/transcript",
    "request_headers": {}
  },
  "asr": {
    "quality": "high",
    "provider": "elevenlabs",
    "user_input_audio_format": "pcm_16000",
    "keywords": []
  },
  "tts": {
    "model_id": "eleven_flash_v2",
    "voice_id": "cjVigY5qzO86Huf0OWal",
    "agent_output_audio_format": "pcm_16000",
    "stability": 0.5,
    "speed": 1,
    "similarity_boost": 0.8,
    "optimize_streaming_latency": 3
  },
  "turn": {
    "turn_timeout": 7,
    "silence_end_call_timeout": -1,
    "turn_eagerness": "normal",
    "mode": "turn"
  },
  "vad": {
    "background_voice_detection": false
  },
  "conversation": {
    "max_duration_seconds": 600,
    "client_events": [
      "audio",
      "interruption",
      "agent_response",
      "user_transcript"
    ]
  },
  "privacy": {
    "record_voice": true,
    "retention_days": -1,
    "delete_transcript_and_pii": false,
    "delete_audio": false,
    "apply_to_existing_conversations": false,
    "zero_retention_mode": false
  },
  "call_limits": {
    "agent_concurrency_limit": -1,
    "daily_limit": 100000,
    "bursting_enabled": true
  },
  "language": "en",
  "cascade_timeout_seconds": 4,
  "tags": [
    "production",
    "v1"
  ],
  "overrides": {
    "first_message": false
  },
  "metadata": {
    "created_at_unix_secs": 1714000000,
    "updated_at_unix_secs": 1714000000,
    "created_from": "api",
    "last_updated_from": "api"
  }
}

SDK Code

import { ElevenLabsClient } from "@elevenlabs/elevenlabs-js";

async function main() {
    const client = new ElevenLabsClient();
    await client.speechEngine.update("seng_3701k3ttaq12ewp8b7qv5rfyszkz", {});
}
main();

from elevenlabs import ElevenLabs

client = ElevenLabs()

client.speech_engine.update(
    speech_engine_id="seng_3701k3ttaq12ewp8b7qv5rfyszkz",
)

package main

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

func main() {

	url := "https://api.elevenlabs.io/v1/speech-engine/seng_3701k3ttaq12ewp8b7qv5rfyszkz"

	payload := strings.NewReader("{}")

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

	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))

}

require 'uri'
require 'net/http'

url = URI("https://api.elevenlabs.io/v1/speech-engine/seng_3701k3ttaq12ewp8b7qv5rfyszkz")

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

request = Net::HTTP::Patch.new(url)
request["Content-Type"] = 'application/json'
request.body = "{}"

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

import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.patch("https://api.elevenlabs.io/v1/speech-engine/seng_3701k3ttaq12ewp8b7qv5rfyszkz")
  .header("Content-Type", "application/json")
  .body("{}")
  .asString();

<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('PATCH', 'https://api.elevenlabs.io/v1/speech-engine/seng_3701k3ttaq12ewp8b7qv5rfyszkz', [
  'body' => '{}',
  'headers' => [
    'Content-Type' => 'application/json',
  ],
]);

echo $response->getBody();

using RestSharp;

var client = new RestClient("https://api.elevenlabs.io/v1/speech-engine/seng_3701k3ttaq12ewp8b7qv5rfyszkz");
var request = new RestRequest(Method.PATCH);
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);

import Foundation

let headers = ["Content-Type": "application/json"]
let parameters = [] as [String : Any]

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

let request = NSMutableURLRequest(url: NSURL(string: "https://api.elevenlabs.io/v1/speech-engine/seng_3701k3ttaq12ewp8b7qv5rfyszkz")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "PATCH"
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()