Flutter SDK

This SDK has the capabilities related to device intelligence and OTL

Integration Steps

At its core, the solution functions through three straightforward steps:

  1. Start by installing OTL SDK with mobile application.
  2. call the authenticate()method. This initialises the SDK and makes the initiate api call.
  3. You can then utilize our API to access user insights, aiding you in deciding the subsequent actions for your user.

Flow Diagram

This diagram shows the interactions between a merchant's mobile app and Bureau's SDK.

  1. sessionId is generated by the client backend and sent to the SDK.
  2. phoneNumber is entered by the user
  3. Invoke the authenticate function in SDK to make the initiate api call.
  4. Upon successful submission of the parameters, a callback is received in the SDK. The next steps can be taken based on the callback (success/failure).
  5. If the callback is successful, Invoke the Bureau's backend API v2/auth/userinfo to fetch user info for OTL.
  6. Based on the user info, you can determine to login or send OTP as SMS in case of failure.

Step 1 - SDK Installation

 Install onetaplogin: 1.3.7

Step 2 - Initialise SDK

Android Changes

Android outer level build.gradle changes

buildscript {
  repositories {
    maven {
      url = uri("https://storage.googleapis.com/r8-releases/raw")
  dependencies {

Android Manifest changes

//Add the folowing call if targeting S+ devices


or if you are using network config

<?xml version="1.0" encoding="utf-8"?>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="false">PLEASE CONTACT BUREAU TO GET DOMAIN</domain>

IOS Changes

Make the below changes to Info.plist


On Production

// Import package
import 'package:onetaplogin/onetaplogin.dart';

// Authenticate : phoneNumber should be starting with 91
int status = await Onetaplogin.authenticate(
					timeoutinMs:timeoutinMs); //we suggest atleast 4*1000 milli sec



Onetaplogin.authenticate()(OTL) is available only in Android and IOS platforms

On Sandbox

// Import package
import 'package:onetaplogin/onetaplogin.dart';

// Authenticate : phoneNumber should be starting with 91
int status = await Onetaplogin.authenticate(
  				env : "Sandbox",
					timeoutinMs:timeoutinMs); //we suggest atleast 4*1000 milli sec

The status object for authenticate method would be an integer which mean as mentioned in SDK Responses

SDK Responses


Step 3 - Invoke API for User Info

To access insights from users for OTL, integrating with Bureau's backend API is a must for both OTL.

Please find below the link to the respective API documentations:

OTL - https://docs.bureau.id/reference/one-tap-login#userinfo-api-call


API's are authenticated via an clientID and secret, they have to be base64 encoded and sent in the header with the parameter name as Authorisation.

Authorisation : Base64(clientID:secret)

curl --location --request GET 'https://api.sandbox.bureau.id/v2/auth/userinfo?transactionId=E1DA15EB-1111-1111-A9FA-2F1F65A9D046' \
--header 'Authorization: Basic MzNjMDBg0YzZWM3NTI1OWNiOA=='

curl --location --request GET 'https://api.bureau.id/v2/auth/userinfo?transactionId=E1DA15EB-1111-1111-A9FA-2F1F65A9D046' \
--header 'Authorization: Basic MzNjMDBg0YzZWM3NTI1OWNiOA=='

API Response

Bureau's Backend API will return one of the following HTTP status codes for every request:

  "mobileNumber": "919932403339",
  "country_code": "IN",
  "status": "Success",
  "authenticatedAt": "1704364405"
    "statusCode": 400,
    "error": {
        "code": 0,
        "type": "BAD_REQUEST",
        "message": "Session key is missing",
        "description": "request does not contain additionalData.sessionKey param in request",
        "referenceId": "24f94ae8-xxxx-48a4-xxxx-b25f99fb06d9",
        "metadata": null
    "timestamp": 1658402143450,
    "merchantId": "auth0|61dfbbxxxx3420071be7021",
    "requestId": "66403193-xxxx-44bc-xxxx-14735a45dfeb"
  "data": null,
  "errors": {
    "status": 401,
    "errorCode": "UNAUTHORIZED",
    "service": "Overwatch"
  "message": "",
  "meta": {
    "length": 0,
    "took": 0,
    "total": 0
    "error": {
        "code": 422,
        "description": "Failed to find fingerprint for given session key",
        "message": "NO_RECORD_FOUND",
        "metadata": null,
        "referenceId": "",
        "type": "NO_RECORD_FOUND"
    "merchantId": "auth0|61dfbbxxxx420071be7021",
    "requestId": "24e1aa7f-xxxx-404d-xxxx-5f8a0227e8f0",
    "statusCode": 422,
    "timestamp": 1658402132141
  "error": {
    "code": 0,
    "description": "",
    "message": "Server encountered an error",
    "metadata": null,
    "referenceId": "86529a18-a5cb-4da9-91b0-8d04cdb9167e",
  "merchantId": "auth0|61dfxxxx0071be7021",
  "requestId": "c69d86f0-xxxx-4ef0-xxxx-e687d595a507",
  "statusCode": 500,
  "timestamp": 1657009043753