Stream Avatar Realtime Word Timestamps

Open a Server-Sent Events (text/event-stream) stream of per-word timestamps for a session. Each data: frame is a WordBatch ({"words": [{"word", "start", "end"}, ...]}); times are in seconds from the start of the streamed audio (matching OpenAI Whisper and ElevenLabs). Punctuation is emitted as its own word event. Batches are capped at ~1s of audio or 10 words, whichever comes first. Late subscribers receive the full session history; completed sessions are served from a durable snapshot. The stream ends with a single event: end frame carrying a WordsEndEvent.

GET /v3/avatar-realtime/{stream_id}/words

Stream Avatar Realtime Word Timestamps

cURL

curl --request GET \
  --url https://api.heygen.com/v3/avatar-realtime/{stream_id}/words \
  --header 'x-api-key: <api-key>'

import requests

url = "https://api.heygen.com/v3/avatar-realtime/{stream_id}/words"

headers = {"x-api-key": "<api-key>"}

response = requests.get(url, headers=headers)

print(response.text)

const options = {method: 'GET', headers: {'x-api-key': '<api-key>'}};

fetch('https://api.heygen.com/v3/avatar-realtime/{stream_id}/words', 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/{stream_id}/words",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
  CURLOPT_HTTPHEADER => [
    "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"
	"net/http"
	"io"
)

func main() {

	url := "https://api.heygen.com/v3/avatar-realtime/{stream_id}/words"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("x-api-key", "<api-key>")

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.get("https://api.heygen.com/v3/avatar-realtime/{stream_id}/words")
  .header("x-api-key", "<api-key>")
  .asString();

require 'uri'
require 'net/http'

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

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

request = Net::HTTP::Get.new(url)
request["x-api-key"] = '<api-key>'

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

200

{
  "words": [
    {
      "word": "<string>",
      "start": 123,
      "end": 123
    }
  ]
}

{
  "error": {
    "code": "invalid_parameter",
    "message": "Video not found",
    "param": "<string>",
    "doc_url": "<string>"
  }
}

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

{
  "error": {
    "code": "not_found",
    "message": "Streaming session not found.",
    "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.

Path Parameters

stream_id · string · required

Streaming session identifier returned by POST /v3/avatar-realtime.

Response

200

text/event-stream

Server-Sent Events stream (text/event-stream). Each data: frame carries one WordBatch JSON payload; the stream terminates with a single event: end frame whose data is a WordsEndEvent.

One SSE data: payload — a batch of words that share a ~1s window.

words · WordEvent · object[] · required

Words in this batch, ordered by start time.

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