Use ElevenLabs in Hermes Agent.
ElevenLabs provides six audio endpoints through RunAPI — turbo-v2.5 TTS with sub-second latency, multilingual-v2 covering 29 languages, dialogue-v3 for multi-speaker conversations, sound effects, speech-to-text transcription, and vocal isolation. Hermes Agent calls them through the custom:runapi provider with one API key.
Use RunAPI to generate speech audio with ElevenLabs text-to-speech.
Requirements:
- Read the API key from RUNAPI_API_KEY.
- Use the custom:runapi provider with base_url https://runapi.ai/v1.
- Call POST https://runapi.ai/api/v1/elevenlabs/text_to_speech
- Set model to "text-to-speech-turbo-v2.5".
- Set text to the content you want spoken.
- Optionally set voice to a specific ElevenLabs voice ID.
- Optionally set speed between 0.7 and 1.2.
- The task is async. Poll the returned task_id until status is "completed".
- When done, read the audio URL from the response output.
curl -X POST https://runapi.ai/api/v1/elevenlabs/text_to_speech \
-H "Authorization: Bearer $RUNAPI_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"model": "text-to-speech-turbo-v2.5",
"text": "Welcome to RunAPI. This audio was generated by ElevenLabs turbo v2.5.",
"speed": 1.0,
"stability": 0.5,
"similarity_boost": 0.75
}'
{
"task_id": "tsk_abc123",
"status": "pending",
"model": "text-to-speech-turbo-v2.5"
}
Use ElevenLabs in Hermes Agent in three steps
Configure RunAPI
Set RUNAPI_API_KEY in the environment where Hermes Agent runs. If you already added RunAPI as a custom:runapi provider, the same key and base_url handle all ElevenLabs endpoints — TTS, STT, dialogue, sound effects, and audio isolation.
export RUNAPI_API_KEY=runapi_xxx
Call text_to_speech
Send a POST to the text_to_speech endpoint with model set to text-to-speech-turbo-v2.5, the text you want spoken, and optional voice, speed, and stability parameters. Hermes Agent routes the request through the custom:runapi provider. For multilingual output, use text-to-speech-multilingual-v2 with a voice and language_code.
POST /api/v1/elevenlabs/text_to_speech
Poll for the result
The endpoint returns a task_id immediately. Poll the task status endpoint until the status is completed, then read the output audio URL from the response.
GET /api/v1/elevenlabs/text_to_speech/tsk_abc123
ElevenLabs text_to_speech API parameters
| Parameter | Type | Description |
|---|---|---|
model |
string |
Required. text-to-speech-turbo-v2.5 (low latency) or text-to-speech-multilingual-v2 (29 languages). |
text |
string |
Required. The text to convert to speech. Max 5000 characters. |
voice |
string |
ElevenLabs voice ID. Required for multilingual-v2. Turbo-v2.5 uses a default voice if omitted. |
speed |
float |
Optional. Playback speed multiplier. Range 0.7 to 1.2. |
stability |
float |
Optional. Voice consistency. Range 0.0 to 1.0. Lower values add expressiveness. |
similarity_boost |
float |
Optional. Voice similarity enforcement. Range 0.0 to 1.0. |
style |
float |
Optional. Style exaggeration. Range 0.0 to 1.0. |
language_code |
string |
Optional. Target language for multilingual-v2, e.g. en, es, ja. |
callback_url |
string |
Optional. Webhook URL that receives a POST when the task completes. |
What is ElevenLabs on Hermes Agent?
ElevenLabs is the leading text-to-speech API, and Hermes Agent calls it through the custom:runapi provider for voice generation, transcription, and audio processing. The key advantage in Hermes is chaining -- generate speech, then pass the audio URL to InfiniteTalk for a talking avatar or to a video model for complete audiovisual content, all in one agent run. Six endpoints are available including turbo TTS, multilingual voices, multi-speaker dialogue, and sound effects.
ElevenLabs use cases
Conversational AI voice agents
Build voice agents that speak naturally by generating speech through turbo-v2.5 with sub-second latency, suitable for customer service bots, interactive assistants, or phone-based interfaces.
YouTube content narration
Produce voiceover for YouTube videos in consistent character voices, adjusting stability for narrator consistency and style exaggeration for emotional range across an entire series.
Text-to-spoken-video pipelines
Chain ElevenLabs TTS with InfiniteTalk or other video models in a Hermes Agent workflow to go from text to narrated video with a talking avatar in a single automated run.
ElevenLabs + Hermes Agent questions
Yes. Configure RunAPI as a custom:runapi provider in Hermes Agent with base_url https://runapi.ai/v1 and key_env RUNAPI_API_KEY, then call any ElevenLabs endpoint -- text_to_speech, speech_to_text, text_to_dialogue, text_to_sound, or isolate_audio.
Start with stability at 0.5 and similarity_boost at 0.75. Higher stability makes the voice more consistent but less expressive. Higher similarity keeps the voice closer to the original profile. For audiobooks, try stability 0.6-0.8. For conversational content, lower stability (0.3-0.5) adds natural variation.
Use turbo-v2.5 for English content -- it costs roughly half as much per character as multilingual-v2. Break long texts into chunks under 5000 characters per request. Use the RunAPI batch approach to process chapters in parallel rather than sequentially.
Yes. Call the speech_to_text endpoint at /api/v1/elevenlabs/speech_to_text with a source_audio_url. The endpoint supports optional speaker diarization via the diarize parameter and audio event tagging via tag_audio_events. Results are returned asynchronously.
Call the isolate_audio endpoint at /api/v1/elevenlabs/isolate_audio with a source_audio_url pointing to your mixed audio file. The endpoint extracts vocals from background noise and returns a cleaned audio URL. The task is async -- poll or use a callback_url.
Yes. Hermes Agent can generate speech with ElevenLabs, then pass the audio URL to InfiniteTalk for avatar video or to Wan for speech-to-video, creating a complete text-to-spoken-video pipeline in one run.
Hermes Agent general setup
Not configured yet? Start with the RunAPI setup guide for Hermes Agent.
Hermes Agent setup guide →Try ElevenLabs in Hermes Agent today.
Get a free RunAPI key, configure the custom:runapi provider, and generate speech audio with ElevenLabs — six endpoints, one API key, per-character billing.