Create Avatar Realtime Session

Start a low-latency streaming avatar session and return a stream_id. Three modes, selected by the type discriminator: tts (speak a fixed script), audio (drive lip-sync from a pre-existing audio asset), and text_stream (seed with initial text, then append more text deltas over time via POST /v3/avatar-realtime//text — e.g. as an upstream LLM streams tokens). Poll GET /v3/avatar-realtime/ for the session status and HLS playback URL.

POST /v3/avatar-realtime

Create Avatar Realtime Session

cURL

curl --request POST \
  --url https://api.heygen.com/v3/avatar-realtime \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "type": "<string>",
  "avatar_id": "<string>",
  "text": "<string>",
  "voice_id": "<string>"
}
'

import requests

url = "https://api.heygen.com/v3/avatar-realtime"

payload = {
    "type": "<string>",
    "avatar_id": "<string>",
    "text": "<string>",
    "voice_id": "<string>"
}
headers = {
    "x-api-key": "<api-key>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {'x-api-key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    type: '<string>',
    avatar_id: '<string>',
    text: '<string>',
    voice_id: '<string>'
  })
};

fetch('https://api.heygen.com/v3/avatar-realtime', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.heygen.com/v3/avatar-realtime",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'type' => '<string>',
    'avatar_id' => '<string>',
    'text' => '<string>',
    'voice_id' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "x-api-key: <api-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

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

func main() {

	url := "https://api.heygen.com/v3/avatar-realtime"

	payload := strings.NewReader("{\n  \"type\": \"<string>\",\n  \"avatar_id\": \"<string>\",\n  \"text\": \"<string>\",\n  \"voice_id\": \"<string>\"\n}")

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

	req.Header.Add("x-api-key", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.heygen.com/v3/avatar-realtime")
  .header("x-api-key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"type\": \"<string>\",\n  \"avatar_id\": \"<string>\",\n  \"text\": \"<string>\",\n  \"voice_id\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.heygen.com/v3/avatar-realtime")

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

request = Net::HTTP::Post.new(url)
request["x-api-key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"type\": \"<string>\",\n  \"avatar_id\": \"<string>\",\n  \"text\": \"<string>\",\n  \"voice_id\": \"<string>\"\n}"

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

201

{
  "data": {
    "stream_id": "<string>"
  }
}

{
  "error": {
    "code": "invalid_parameter",
    "message": "Invalid 'type'. Must be one of: tts, audio, text_stream.",
    "param": "type",
    "doc_url": null
  }
}

{
  "error": {
    "code": "authentication_failed",
    "message": "Invalid or expired API key. Verify your x-api-key header.",
    "param": null,
    "doc_url": null
  }
}

{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Too many requests. Retry after the duration specified in the Retry-After header.",
    "param": null,
    "doc_url": null
  }
}

Authorizations

ApiKeyAuthBearerAuth

x-api-key · string · header · required

HeyGen API key. Obtain from your HeyGen dashboard.

Body

application/json

CreateAvatarRealtimeTTS

CreateAvatarRealtimeAudio

CreateAvatarRealtimeTextStream

Create a stream with text-to-speech audio.

type · string · required

Audio source type: text-to-speech.

Allowed value: "tts"

avatar_id · string · required

HeyGen photo avatar or motion avatar look ID.

text · string · required

Text script for the avatar to speak.

Minimum string length: 1

voice_id · string · required

Voice ID for text-to-speech.

Response

201

application/json

Created.

data · CreateAvatarRealtimeResponse · object

Response data for POST /v3/avatar-realtime.

Show child attributes