Create standalone OTP

Send an OTP for step-up authentication or standalone verification. Can be initiated with a challenge token (step-up flow) or an identifier (standalone flow).

Note: When a request is blocked by fraud/antispam rules, the server returns 204 No Content rather than a 4xx error, so callers cannot distinguish a blocked attempt from a successful dispatch.

When the identifier is an email whose domain is bound to a SAML connection with enforced login, OTP creation is refused with the saml_login_required error (403) and the flow must be restarted via the SAML initiate endpoint.

POST

session

otp

Create standalone OTP

curl --request POST \
  --url https://{appId}.session.prelude.dev/v1/session/otp \
  --header 'Content-Type: application/json' \
  --data '
{
  "challenge_token": "<string>",
  "code_challenge": "<string>",
  "dispatch_id": "<string>",
  "login_config_id": "<string>"
}
'

import requests

url = "https://{appId}.session.prelude.dev/v1/session/otp"

payload = {
    "challenge_token": "<string>",
    "code_challenge": "<string>",
    "dispatch_id": "<string>",
    "login_config_id": "<string>"
}
headers = {"Content-Type": "application/json"}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    challenge_token: '<string>',
    code_challenge: '<string>',
    dispatch_id: '<string>',
    login_config_id: '<string>'
  })
};

fetch('https://{appId}.session.prelude.dev/v1/session/otp', 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://{appId}.session.prelude.dev/v1/session/otp",
  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([
    'challenge_token' => '<string>',
    'code_challenge' => '<string>',
    'dispatch_id' => '<string>',
    'login_config_id' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "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://{appId}.session.prelude.dev/v1/session/otp"

	payload := strings.NewReader("{\n  \"challenge_token\": \"<string>\",\n  \"code_challenge\": \"<string>\",\n  \"dispatch_id\": \"<string>\",\n  \"login_config_id\": \"<string>\"\n}")

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

	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://{appId}.session.prelude.dev/v1/session/otp")
  .header("Content-Type", "application/json")
  .body("{\n  \"challenge_token\": \"<string>\",\n  \"code_challenge\": \"<string>\",\n  \"dispatch_id\": \"<string>\",\n  \"login_config_id\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://{appId}.session.prelude.dev/v1/session/otp")

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

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"challenge_token\": \"<string>\",\n  \"code_challenge\": \"<string>\",\n  \"dispatch_id\": \"<string>\",\n  \"login_config_id\": \"<string>\"\n}"

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

{
  "code": "bad_request",
  "type": "bad_request"
}

{
  "code": "insufficient_balance",
  "type": "bad_request"
}

{
  "code": "saml_login_required",
  "type": "forbidden",
  "message": "<string>"
}

{
  "code": "internal",
  "type": "internal"
}

Body

application/json

Option 1
Option 2

Either challenge_token or identifier must be provided. Use challenge_token for step-up flows, identifier for standalone OTP.

challenge_token

string

required

The challenge token from a step-up request.

Example:

"eyJhbGciOiJFZERTQSIsInR5cCI6IkpXVCJ9..."

identifier

object

The verification target. Either a phone number or an email address.

Show child attributes

code_challenge

string

PKCE code challenge (S256) for the standalone OTP login flow. Only used with identifier; bound to the verification token so that code_verifier can be replayed against Finalize login. Step-up flows ignore this field — they inherit PKCE from the originating challenge token.

Example:

"E9Melhoa2OwvFrEMTJguCHaoeK1t8URWbuGJSstw-cM"

dispatch_id

string

The identifier of the dispatch from the front-end SDK.

Example:

"123e4567-e89b-12d3-a456-426614174000"

The identifier of the login config to use.

Example:

"lcfg_01jqebhswje1ka1z7ahr9rfsgt"

Response

No Content

Create standalone OTP

curl --request POST \
  --url https://{appId}.session.prelude.dev/v1/session/otp \
  --header 'Content-Type: application/json' \
  --data '
{
  "challenge_token": "<string>",
  "code_challenge": "<string>",
  "dispatch_id": "<string>",
  "login_config_id": "<string>"
}
'

import requests

url = "https://{appId}.session.prelude.dev/v1/session/otp"

payload = {
    "challenge_token": "<string>",
    "code_challenge": "<string>",
    "dispatch_id": "<string>",
    "login_config_id": "<string>"
}
headers = {"Content-Type": "application/json"}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({
    challenge_token: '<string>',
    code_challenge: '<string>',
    dispatch_id: '<string>',
    login_config_id: '<string>'
  })
};

fetch('https://{appId}.session.prelude.dev/v1/session/otp', 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://{appId}.session.prelude.dev/v1/session/otp",
  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([
    'challenge_token' => '<string>',
    'code_challenge' => '<string>',
    'dispatch_id' => '<string>',
    'login_config_id' => '<string>'
  ]),
  CURLOPT_HTTPHEADER => [
    "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://{appId}.session.prelude.dev/v1/session/otp"

	payload := strings.NewReader("{\n  \"challenge_token\": \"<string>\",\n  \"code_challenge\": \"<string>\",\n  \"dispatch_id\": \"<string>\",\n  \"login_config_id\": \"<string>\"\n}")

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

	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://{appId}.session.prelude.dev/v1/session/otp")
  .header("Content-Type", "application/json")
  .body("{\n  \"challenge_token\": \"<string>\",\n  \"code_challenge\": \"<string>\",\n  \"dispatch_id\": \"<string>\",\n  \"login_config_id\": \"<string>\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://{appId}.session.prelude.dev/v1/session/otp")

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

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"challenge_token\": \"<string>\",\n  \"code_challenge\": \"<string>\",\n  \"dispatch_id\": \"<string>\",\n  \"login_config_id\": \"<string>\"\n}"

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

{
  "code": "bad_request",
  "type": "bad_request"
}

{
  "code": "insufficient_balance",
  "type": "bad_request"
}

{
  "code": "saml_login_required",
  "type": "forbidden",
  "message": "<string>"
}

{
  "code": "internal",
  "type": "internal"
}

Documentation

API Reference

Create standalone OTP

Body

Response