Get Employee Leave Data from OneLogin API

Introduction

This article is part of a series on HRIS APIs. In this post, we focus on a common requirement, retrieving employee leave data—and explain how far the OneLogin API can support this use case.

Prerequisites

Before you begin, make sure you have:

• Access to a OneLogin account with API permissions enabled
• A valid OneLogin API client (Client ID and Client Secret)
• Python installed on your system
• The requests library available in your Python environment

API Endpoints

• Base URL
  https://api.onelogin.com
• Authentication Endpoint
  /auth/oauth2/v2/token
• User Data Endpoint
  /api/1/users

Step-by-Step Process

Step 1: Authenticate and Obtain an Access Token

Use the OAuth 2.0 client credentials flow to retrieve an access token.

import requests

client_id = 'YOUR_CLIENT_ID'
client_secret = 'YOUR_CLIENT_SECRET'

auth_url = 'https://api.onelogin.com/auth/oauth2/v2/token'
auth_headers = {
    'Content-Type': 'application/json'
}
auth_data = {
    'grant_type': 'client_credentials',
    'client_id': client_id,
    'client_secret': client_secret
}

response = requests.post(auth_url, headers=auth_headers, json=auth_data)
access_token = response.json().get('access_token')

Step 2: Fetch User Data

Once authenticated, use the access token to retrieve user records from OneLogin.

user_url = 'https://api.onelogin.com/api/1/users'
user_headers = {
    'Authorization': f'Bearer {access_token}'
}

user_response = requests.get(user_url, headers=user_headers)
users = user_response.json()

This endpoint returns identity-related information such as user IDs, names, email addresses, roles, and status.

Step 3: Extract Leave Data (Key Limitation)

At this stage, it’s important to set expectations clearly:

OneLogin does not provide employee leave or attendance data through its API.

If your use case requires leave information, you will need to:

• Integrate with a dedicated HR or payroll system that manages leave
• Use OneLogin user IDs or email addresses as a linking key between systems

Common Pitfalls

• Treating OneLogin as an HR system rather than an identity provider
• Assuming leave or attendance data is available in user objects
• Failing to refresh or reissue access tokens after expiration
• Not validating API response status codes before processing data
• Ignoring pagination when fetching large user directories
• Hardcoding API credentials instead of securing them properly
• Overlooking OneLogin API rate limits during bulk syncs

FAQs

Q: How do I get API credentials for OneLogin?
A: Log in to OneLogin and navigate to Settings → API to create a client and obtain your Client ID and Client Secret.

Q: What happens when the access token expires?
A: You must re-run the authentication flow to obtain a new access token.

Q: Can OneLogin provide employee leave or attendance data?
A: No. OneLogin does not manage or expose leave data via its API.

Q: How should I handle pagination when fetching users?
A: Use the pagination parameters returned in the API response to iterate through user records.

Q: Are there rate limits on the OneLogin API?
A: Yes. Rate limits apply and should be handled according to OneLogin’s API documentation.

Q: Is this API suitable for production use?
A: Yes, provided you follow security best practices and handle tokens, rate limits, and errors correctly.

Q: What response format does the OneLogin API use?
A: All responses are returned in JSON format.

Knit for OneLogin API Integration

If you’re looking to avoid managing OAuth flows, token refresh logic, pagination, and long-term maintenance, Knit provides a streamlined alternative.

By integrating with Knit once, you can access OneLogin data through a unified API layer. Knit handles authentication, authorization, and ongoing integration upkeep, allowing teams to focus on downstream workflows rather than infrastructure complexity.

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Ready to build this integration?
Explore Knit’s OneLogin integration or read more about our Unified HRIS API.