Confidential AI API: Secure LLM Inference at Scale

Encrypted Audio Transcriptions (RVENC)

curl --request POST \
  --url https://gateway.prem.io/rvenc/audio/transcriptions \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "whisper-large-v3",
  "encryptedInference": "encrypted_inference_payload_data",
  "cipherText": "cipher_text_for_key_exchange",
  "nonce": "nonce_value",
  "fileNameNonce": "file_name_nonce_value",
  "encryptedFileName": "encrypted_audio_file_name_data",
  "fileNonce": "file_nonce_value",
  "encryptedFile": "encrypted_audio_file_data"
}
'

import requests

url = "https://gateway.prem.io/rvenc/audio/transcriptions"

payload = {
    "model": "whisper-large-v3",
    "encryptedInference": "encrypted_inference_payload_data",
    "cipherText": "cipher_text_for_key_exchange",
    "nonce": "nonce_value",
    "fileNameNonce": "file_name_nonce_value",
    "encryptedFileName": "encrypted_audio_file_name_data",
    "fileNonce": "file_nonce_value",
    "encryptedFile": "encrypted_audio_file_data"
}
headers = {
    "Authorization": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    model: 'whisper-large-v3',
    encryptedInference: 'encrypted_inference_payload_data',
    cipherText: 'cipher_text_for_key_exchange',
    nonce: 'nonce_value',
    fileNameNonce: 'file_name_nonce_value',
    encryptedFileName: 'encrypted_audio_file_name_data',
    fileNonce: 'file_nonce_value',
    encryptedFile: 'encrypted_audio_file_data'
  })
};

fetch('https://gateway.prem.io/rvenc/audio/transcriptions', 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://gateway.prem.io/rvenc/audio/transcriptions",
  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([
    'model' => 'whisper-large-v3',
    'encryptedInference' => 'encrypted_inference_payload_data',
    'cipherText' => 'cipher_text_for_key_exchange',
    'nonce' => 'nonce_value',
    'fileNameNonce' => 'file_name_nonce_value',
    'encryptedFileName' => 'encrypted_audio_file_name_data',
    'fileNonce' => 'file_nonce_value',
    'encryptedFile' => 'encrypted_audio_file_data'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <api-key>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($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://gateway.prem.io/rvenc/audio/transcriptions"

	payload := strings.NewReader("{\n  \"model\": \"whisper-large-v3\",\n  \"encryptedInference\": \"encrypted_inference_payload_data\",\n  \"cipherText\": \"cipher_text_for_key_exchange\",\n  \"nonce\": \"nonce_value\",\n  \"fileNameNonce\": \"file_name_nonce_value\",\n  \"encryptedFileName\": \"encrypted_audio_file_name_data\",\n  \"fileNonce\": \"file_nonce_value\",\n  \"encryptedFile\": \"encrypted_audio_file_data\"\n}")

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

	req.Header.Add("Authorization", "<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://gateway.prem.io/rvenc/audio/transcriptions")
  .header("Authorization", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"whisper-large-v3\",\n  \"encryptedInference\": \"encrypted_inference_payload_data\",\n  \"cipherText\": \"cipher_text_for_key_exchange\",\n  \"nonce\": \"nonce_value\",\n  \"fileNameNonce\": \"file_name_nonce_value\",\n  \"encryptedFileName\": \"encrypted_audio_file_name_data\",\n  \"fileNonce\": \"file_nonce_value\",\n  \"encryptedFile\": \"encrypted_audio_file_data\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://gateway.prem.io/rvenc/audio/transcriptions")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"whisper-large-v3\",\n  \"encryptedInference\": \"encrypted_inference_payload_data\",\n  \"cipherText\": \"cipher_text_for_key_exchange\",\n  \"nonce\": \"nonce_value\",\n  \"fileNameNonce\": \"file_name_nonce_value\",\n  \"encryptedFileName\": \"encrypted_audio_file_name_data\",\n  \"fileNonce\": \"file_nonce_value\",\n  \"encryptedFile\": \"encrypted_audio_file_data\"\n}"

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

{
  "status": 200,
  "data": {
    "id": "123"
  },
  "error": null,
  "log": null,
  "validator": null,
  "support_id": null,
  "message": "Resource created successfully",
  "env": "development"
}

{
  "status": 400,
  "error": "Some error message",
  "message": null,
  "env": "development",
  "log": {
    "request_id": "req_1234567890"
  },
  "support_id": "support_uuidv7-something-else",
  "data": {},
  "validator": {
    "email": "Invalid email address",
    "password": "Password is required"
  }
}

{
  "status": 401,
  "error": "Some error message",
  "message": null,
  "env": "development",
  "log": {
    "request_id": "req_1234567890"
  },
  "support_id": "support_uuidv7-something-else",
  "data": {},
  "validator": {
    "email": "Invalid email address",
    "password": "Password is required"
  }
}

{
  "status": 403,
  "error": "Some error message",
  "message": null,
  "env": "development",
  "log": {
    "request_id": "req_1234567890"
  },
  "support_id": "support_uuidv7-something-else",
  "data": {},
  "validator": {
    "email": "Invalid email address",
    "password": "Password is required"
  }
}

{
  "status": 413,
  "error": "Audio file size exceeds the maximum allowed limit of 25MB."
}

{
  "status": 429,
  "error": "Rate limit exceeded. Please try again later."
}

POST

rvenc

audio

transcriptions

Encrypted Audio Transcriptions (RVENC)

curl --request POST \
  --url https://gateway.prem.io/rvenc/audio/transcriptions \
  --header 'Authorization: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "model": "whisper-large-v3",
  "encryptedInference": "encrypted_inference_payload_data",
  "cipherText": "cipher_text_for_key_exchange",
  "nonce": "nonce_value",
  "fileNameNonce": "file_name_nonce_value",
  "encryptedFileName": "encrypted_audio_file_name_data",
  "fileNonce": "file_nonce_value",
  "encryptedFile": "encrypted_audio_file_data"
}
'

import requests

url = "https://gateway.prem.io/rvenc/audio/transcriptions"

payload = {
    "model": "whisper-large-v3",
    "encryptedInference": "encrypted_inference_payload_data",
    "cipherText": "cipher_text_for_key_exchange",
    "nonce": "nonce_value",
    "fileNameNonce": "file_name_nonce_value",
    "encryptedFileName": "encrypted_audio_file_name_data",
    "fileNonce": "file_nonce_value",
    "encryptedFile": "encrypted_audio_file_data"
}
headers = {
    "Authorization": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    model: 'whisper-large-v3',
    encryptedInference: 'encrypted_inference_payload_data',
    cipherText: 'cipher_text_for_key_exchange',
    nonce: 'nonce_value',
    fileNameNonce: 'file_name_nonce_value',
    encryptedFileName: 'encrypted_audio_file_name_data',
    fileNonce: 'file_nonce_value',
    encryptedFile: 'encrypted_audio_file_data'
  })
};

fetch('https://gateway.prem.io/rvenc/audio/transcriptions', 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://gateway.prem.io/rvenc/audio/transcriptions",
  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([
    'model' => 'whisper-large-v3',
    'encryptedInference' => 'encrypted_inference_payload_data',
    'cipherText' => 'cipher_text_for_key_exchange',
    'nonce' => 'nonce_value',
    'fileNameNonce' => 'file_name_nonce_value',
    'encryptedFileName' => 'encrypted_audio_file_name_data',
    'fileNonce' => 'file_nonce_value',
    'encryptedFile' => 'encrypted_audio_file_data'
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: <api-key>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($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://gateway.prem.io/rvenc/audio/transcriptions"

	payload := strings.NewReader("{\n  \"model\": \"whisper-large-v3\",\n  \"encryptedInference\": \"encrypted_inference_payload_data\",\n  \"cipherText\": \"cipher_text_for_key_exchange\",\n  \"nonce\": \"nonce_value\",\n  \"fileNameNonce\": \"file_name_nonce_value\",\n  \"encryptedFileName\": \"encrypted_audio_file_name_data\",\n  \"fileNonce\": \"file_nonce_value\",\n  \"encryptedFile\": \"encrypted_audio_file_data\"\n}")

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

	req.Header.Add("Authorization", "<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://gateway.prem.io/rvenc/audio/transcriptions")
  .header("Authorization", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"whisper-large-v3\",\n  \"encryptedInference\": \"encrypted_inference_payload_data\",\n  \"cipherText\": \"cipher_text_for_key_exchange\",\n  \"nonce\": \"nonce_value\",\n  \"fileNameNonce\": \"file_name_nonce_value\",\n  \"encryptedFileName\": \"encrypted_audio_file_name_data\",\n  \"fileNonce\": \"file_nonce_value\",\n  \"encryptedFile\": \"encrypted_audio_file_data\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://gateway.prem.io/rvenc/audio/transcriptions")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"whisper-large-v3\",\n  \"encryptedInference\": \"encrypted_inference_payload_data\",\n  \"cipherText\": \"cipher_text_for_key_exchange\",\n  \"nonce\": \"nonce_value\",\n  \"fileNameNonce\": \"file_name_nonce_value\",\n  \"encryptedFileName\": \"encrypted_audio_file_name_data\",\n  \"fileNonce\": \"file_nonce_value\",\n  \"encryptedFile\": \"encrypted_audio_file_data\"\n}"

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

{
  "status": 200,
  "data": {
    "id": "123"
  },
  "error": null,
  "log": null,
  "validator": null,
  "support_id": null,
  "message": "Resource created successfully",
  "env": "development"
}

{
  "status": 400,
  "error": "Some error message",
  "message": null,
  "env": "development",
  "log": {
    "request_id": "req_1234567890"
  },
  "support_id": "support_uuidv7-something-else",
  "data": {},
  "validator": {
    "email": "Invalid email address",
    "password": "Password is required"
  }
}

{
  "status": 401,
  "error": "Some error message",
  "message": null,
  "env": "development",
  "log": {
    "request_id": "req_1234567890"
  },
  "support_id": "support_uuidv7-something-else",
  "data": {},
  "validator": {
    "email": "Invalid email address",
    "password": "Password is required"
  }
}

{
  "status": 403,
  "error": "Some error message",
  "message": null,
  "env": "development",
  "log": {
    "request_id": "req_1234567890"
  },
  "support_id": "support_uuidv7-something-else",
  "data": {},
  "validator": {
    "email": "Invalid email address",
    "password": "Password is required"
  }
}

{
  "status": 413,
  "error": "Audio file size exceeds the maximum allowed limit of 25MB."
}

{
  "status": 429,
  "error": "Rate limit exceeded. Please try again later."
}

TypeScript SDK

The SDK is available on GitHub: premAI-io/api-sdk-ts

Basic Setup

Create a 32-byte KEK. Encode it as 64 hexadecimal characters. Keep the KEK. Reuse it for later requests.

export CLIENT_KEK="$(openssl rand -hex 32)"

Create the client:

import { createRvencClient } from "@premai/api-sdk";
import fs from "fs";

const client = await createRvencClient({
  apiKey: process.env.PREM_API_KEY,
  clientKEK: process.env.CLIENT_KEK
});

Pre-generate Keys

You can pre-generate encryption keys and reuse them with the same KEK:

import { createRvencClient, generateEncryptionKeys } from "@premai/api-sdk";

const encryptionKeys = await generateEncryptionKeys();

const client = await createRvencClient({
  apiKey: process.env.PREM_API_KEY,
  clientKEK: process.env.CLIENT_KEK,
  encryptionKeys,
  requestTimeoutMs: 60000,  // optional
  maxBufferSize: 20 * 1024 * 1024, // optional
});

Basic Transcription

const transcription = await client.audio.transcriptions.create({
  file: fs.createReadStream('./audio.wav'),
  model: 'deepgram/general-nova-3',
  smart_format: true,
});

console.log(transcription.results?.channels?.[0]?.alternatives?.[0]?.transcript ?? '');

Transcription with Options

const transcription = await client.audio.transcriptions.create({
  file: fs.createReadStream('./audio.mp3'),
  model: 'deepgram/general-nova-3',
  diarize: true,
  smart_format: true,
});

Configuration

Option	Default	Description
`file`	required	Audio file (ReadStream, Buffer, Blob, etc.)
`model`	required	Current enabled model ID: `'deepgram/general-nova-3'`
`diarize`	`false`	Ask the backend to identify speakers
`smart_format`	`false`	Ask the backend to format dates, numbers, and punctuation

Note: The current Deepgram route is non-streaming and returns Deepgram-style metadata and results, not an OpenAI { text } object.

OpenAI-Compatible API Server

Run the SDK as a standalone server. The proxy requires the same 32-byte KEK described above and automatically manages one DEK store for each API key:

bunx -p @premai/api-sdk@1.0.66 confidential-proxy --kek "$CLIENT_KEK"
# Server runs on http://127.0.0.1:8787

Use the server with any OpenAI-compatible client:

curl http://127.0.0.1:8787/v1/audio/transcriptions \
  -H "Authorization: Bearer your-api-key" \
  -F "file=@audio.mp3" \
  -F "model=deepgram/general-nova-3"

You can also use the OpenAI SDK against the local proxy:

import OpenAI from "openai";

const client = new OpenAI({
  apiKey: process.env.PREM_API_KEY,
  baseURL: "http://127.0.0.1:8787/v1",
});

const transcription = await client.audio.transcriptions.create({
  file: fs.createReadStream('./audio.mp3'),
  model: 'deepgram/general-nova-3',
});

console.log(JSON.stringify(transcription, null, 2));

The server establishes a secure client instance for each API key.

API Reference

Authorizations

Authorization

string

header

required

Send your access token as header Authorization: Bearer {accessToken}

Authorization

string

header

required

Your API key that starts with sk_live or sk_test. You can create yours at go.prem.io/api-keys.

Body

application/json

Audio transcription request with an end-to-end encrypted payload and the key material needed to decrypt it.

model

string

required

Model identifier to use for transcription

encryptedInference

string

required

Encrypted JSON string containing all audio transcription parameters. When decrypted, this string must match the structure shown in the expandable _decryptedInference property below (reference only - do not send this property).

cipherText

string

required

Cipher text for shared secret generation (ECDH key exchange)

nonce

string

required

Nonce used for encrypting the inference payload

encryptedFileName

string

required

The encrypted audio file name. The file name is encrypted using XChaCha20-Poly1305 with the shared secret and fileNameNonce.

fileNameNonce

string

required

Nonce used for encrypting the encrypted audio file name

encryptedFile

string

required

The encrypted audio file data. The audio content is encrypted using XChaCha20-Poly1305 with the shared secret and fileNonce.

fileNonce

string

required

Nonce used for encrypting the encrypted audio file

Response

Encrypted audio transcription response. The response contains the encrypted transcription result which must be decrypted using the shared secret derived from the request's cipherText, along with the response nonce.

status

enum<integer>

required

Status code of the response

Available options:

200,

201,

202

data

object

required

Encrypted audio transcription response. Contains the encrypted transcription result that must be decrypted using the shared secret derived from the request's cipherText.

Show child attributes

Example:

{
  "encryptedResponse": "a1b2c3d4e5f67890abcdef1234567890abcdef123456789012345678901234567890abcdef...",
  "nonce": "f6e5d4c3b2a19876543210fedcba9876"
}

message

string | null

required

Message of the response, human readable

Example:

"Resource created successfully"

env

enum<string>

required

API environment

Available options:

development,

production

error

string | null

Error message of the response, human readable

Example:

"Invalid email address"

log

Useful informaiton, not always present, to debug the response

Examples:

{ "request_id": "req_1234567890" }

"Some pertinent log message"

validator

Validator response object, each key is the field name and value is the error message

Example:

{
  "email": "Invalid email address",
  "password": "Password is required"
}

support_id

string<uuid> | null

Support ID linked to the response, used to identify it when talking with our team

Example:

"support_uuidv7-something-else"

Endpoints

API Keys

Billing

Encrypted Audio Transcriptions (RVENC)

TypeScript SDK

Basic Setup

Pre-generate Keys

Basic Transcription

Transcription with Options

Configuration

OpenAI-Compatible API Server

API Reference

Authorizations

Body

Response

​TypeScript SDK

​Basic Setup

​Pre-generate Keys

​Basic Transcription

​Transcription with Options

​Configuration

​OpenAI-Compatible API Server

​API Reference

Authorizations

Body

Response

TypeScript SDK

Basic Setup

Pre-generate Keys

Basic Transcription

Transcription with Options

Configuration

OpenAI-Compatible API Server

API Reference