curl -X POST 'https://api.elevenlabs.io/v1/convai/llm-usage/calculate' \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
  "prompt_length": 0,
  "number_of_pages": 0,
  "rag_enabled": true
}'

# POST /v1/convai/llm-usage/calculate (ElevenLabs API)
Base URL: https://api.elevenlabs.io
Auth: xi-api-key: <ELEVENLABS_API_KEY>
Last verified: 2026-09-03

> Calculate Expected Llm Usage

## Critical Gotchas
* Authentication uses the non-standard `xi-api-key` header, not `Authorization: Bearer`. Sending a Bearer token returns HTTP 401.
* Text-to-speech responses are raw binary audio, not JSON. Write the body to a file (`--output speech.mp3`) rather than parsing it.

## cURL
curl -X POST 'https://api.elevenlabs.io/v1/convai/llm-usage/calculate' \
  -H "xi-api-key: $ELEVENLABS_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{"prompt_length":0,"number_of_pages":0,"rag_enabled":true}'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| prompt_length | body | integer | Yes | Length of the prompt in characters. |
| number_of_pages | body | integer | Yes | Pages of content in PDF documents or URLs in the agent's... |
| rag_enabled | body | boolean | Yes | Whether RAG is enabled. |

## Response (200 OK)
{"llm_prices":[{"llm":"gpt-4o-mini","price_per_minute":0}]}

---
Need an API key? Get one at https://elevenlabs.io/app/sign-up

POST

/v1/convai/llm-usage/calculate

ElevenLabs API

Calculate Expected Llm Usage

Base URL: https://api.elevenlabs.io
Auth: xi-api-key: <ELEVENLABS_API_KEY>
Last verified: 2026-09-03 · upstream hash matched

Actions

Agents: curl -H "Accept: text/markdown" this URL
→ 216 tokens · Vary: Accept

Critical gotchas

Authentication uses the non-standard xi-api-key header, not Authorization: Bearer. Sending a Bearer token returns HTTP 401.

Text-to-speech responses are raw binary audio, not JSON. Write the body to a file (--output speech.mp3) rather than parsing it.

cURL

curl -X POST 'https://api.elevenlabs.io/v1/convai/llm-usage/calculate' \  -H "xi-api-key: $ELEVENLABS_API_KEY" \  -H 'Content-Type: application/json' \  -d '{  "prompt_length": 0,  "number_of_pages": 0,  "rag_enabled": true}'

Get a free ElevenLabs API key → sponsored

Parameters

Name	In	Type	Required	Description
prompt_length	body	integer	Yes	Length of the prompt in characters.
number_of_pages	body	integer	Yes	Pages of content in PDF documents or URLs in the agent's knowledge base.
rag_enabled	body	boolean	Yes	Whether RAG is enabled.

Response 200 OK

{
  "llm_prices": [
    {
      "llm": "gpt-4o-mini",
      "price_per_minute": 0
    }
  ]
}