> ## Documentation Index
> Fetch the complete documentation index at: https://hub.stackone.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Unified HRIS API

> Unified HRIS API for HR management across platforms, with consistent data models for employee data, shifts, time-off, documents, and benefits.

<Warning>
  **Legacy documentation.** The Legacy Unified APIs are no longer in active development. Existing functionality remains supported, and no new features or enhancements will be added.

  For the current StackOne platform, connectors, and agent tooling, see [docs.stackone.com](https://docs.stackone.com).
</Warning>

## What is a Unified API?

A **unified API** provides a single, standardized interface to interact with multiple third-party providers. Instead of learning each provider's unique API format, authentication scheme, and data model, you write code once, and StackOne handles the differences.

**What StackOne normalizes:**

* **Data models** – Consistent field names and structures across providers (e.g., `files` in Google Drive, SharePoint, and Dropbox all return the same schema; `users` in Google Workspace, Okta, and 1Password all return the same schema)
* **Authentication** – OAuth, API keys, and tokens are managed per-provider; you just pass an `x-account-id` header
* **Pagination** – Cursor-based pagination works the same regardless of whether the provider uses offsets, pages, or cursors
* **Error formats** – Standardized error responses with provider-specific details when available

<Tip>
  **Building AI agents?** Use the [MCP Server](https://docs.stackone.com/embed/call-actions/mcp), an [AI Toolset SDK](https://docs.stackone.com/embed/call-actions/agent-sdk), or the [Actions API (RPC)](https://docs.stackone.com/platform/api-reference/actions/make-an-rpc-call-to-an-action) instead. Same data, optimized for LLM tool calling.
</Tip>

## Benefits of the HRIS API

<AccordionGroup>
  <Accordion title="Real-Time Data Synchronization">
    StackOne's APIs support real-time data polling, allowing for immediate updates and synchronization across platforms.
  </Accordion>

  <Accordion title="Privacy-First Design Ensuring Compliance">
    With a [focus on security](https://www.stackone.com/blog/why-your-choice-of-unified-api-could-make-or-break-compliance), StackOne's architecture avoids unnecessary data storage, maintaining compliance with data protection regulations.
  </Accordion>

  <Accordion title="Synthetic and Native Webhooks for Updates">
    The platform provides both [synthetic and native webhooks](/legacy-unified-apis/common-guide/webhooks), enabling real-time notifications for employee and payroll changes.
  </Accordion>

  <Accordion title="Comprehensive HRIS Integration Coverage">
    StackOne offers [pre-built connectors](https://www.stackone.com/integrations) with a wide range of HRIS platforms, simplifying the integration process.
  </Accordion>
</AccordionGroup>

## Key Features

The table below shows key features of the HRIS API that make human resources management easier, from real-time employee tracking to payroll management:

| **Feature**                         | **Description**                                                                                               |
| ----------------------------------- | ------------------------------------------------------------------------------------------------------------- |
| Comprehensive Employee Management   | Easily create, update, and retrieve employee profiles, including personal information and employment history. |
| Payroll and Compensation Management | Manage payroll data, track compensation ranges, and update salary information for employees.                  |
| Leave and Attendance Tracking       | Monitor and update employee attendance, time-off requests, and manage leave balances.                         |
| Real-Time Webhooks                  | Receive instant notifications for changes in employee profiles, payroll, or leave data.                       |
| Document Management                 | Upload, download, and manage employee documents such as contracts and performance reviews.                    |
| Benefits Management                 | Record and manage employee benefits, including health, retirement, and wellness programs.                     |
| Employee Onboarding and Offboarding | Handle employee onboarding, document signing, and offboarding processes, tracking key milestones.             |

## StackOne SDKs & OpenAPI Specification

<p class="sdk-text">Use our official SDKs for faster integration. Build with language-native libraries. Full list [here](https://docs.stackone.com/platform-api/api-sdks).</p>

<CardGroup cols={2}>
  <Card title="OpenAPI Specification" icon="link" href="https://api.eu1.stackone.com/oas/hris.json" arrow="true" cta="Click here" />

  <Card title="Popular SDKs" icon="download" class="sdk-card">
    [Node.js](https://www.npmjs.com/package/@stackone/stackone-client-ts)
    [Java (JVM)](https://mvnrepository.com/artifact/com.stackone/stackone-client-java)
    [PHP](https://packagist.org/packages/stackone/client-sdk)
    [Ruby](https://rubygems.org/gems/stackone_client)
  </Card>
</CardGroup>

## Entity Model and Relationships

The following diagram illustrates the key entities within the HRIS API:

```mermaid theme={null}
erDiagram
    Employee {
        string id
        string company_id
        string manager_id
        string job_id
        string department_id
    }

    Employment {
        string id
        string employee_id
    }

    TimeOff {
        string id
        string employee_id
        string approver_id
        string time_off_policy_id
    }

    TimeOffPolicies {
        string id
    }

    Company {
        string id
    }

    TimeOffBalances {
        string id
        string employee_id
        string policy_id
    }

    TimeEntries {
        string id
        string employee_id
    }

    Document {
        string id
        string employee_id
        string category_id
    }

    Location {
        string id
    }

    Benefit {
        string id
    }

    Group {
        string id
    }

    Job {
        string id
    }

    WorkEligibility {
        string id
        string employee_id
    }

    DocumentCategory {
        string id
    }

    CustomFieldDefinition {
        string id
    }

    Employee ||--o{ Employment : ""
    Employee ||--o{ TimeOff : ""
    Employee ||--o{ TimeOffBalances : ""
    Employee ||--o{ WorkEligibility : ""
    Employee ||--o{ Document : ""
    Employee ||--o{ TimeEntries : ""

    Company ||--o{ Employee : ""
    Company ||--o{ Location : ""

    Job ||--o{ Employee : ""

    Location ||--o{ Employee : ""

    Group ||--o{ Employee : ""
    Group ||--o{ Employment : ""

    Benefit ||--o{ Employee : ""

    TimeOffPolicies ||--o{ TimeOff : ""
    TimeOffPolicies ||--o{ TimeOffBalances : ""

    DocumentCategory ||--o{ Document : ""
```

The following table outlines key entities within the HRIS system and provides a brief description of each.

| Entity            | Description                                                                                                                                        |
| ----------------- | -------------------------------------------------------------------------------------------------------------------------------------------------- |
| Companies         | Represents the high-level organizational details of companies present in the underlying system, such as name, display name, and other identifiers. |
| Employees         | Contains comprehensive information about employees, including personal details, contact information, and relationship to other entities.           |
| Employments       | Details the employment records of each employee including job positions, start and end dates, compensation details, and more.                      |
| Locations         | Manages information about the work locations. Location may contain a name associated contact details.                                              |
| Time Off          | Manages records of employee leave requests and their approval status, including request type, duration, and related policies.                      |
| Time Off Balances | Tracks the available balance of time off for employees according to specific policies.                                                             |
| Time Off Policies | Defines the policies governing time off requests, including types of leave, duration units, and associated reasons.                                |
| Benefits          | Manages information about employee benefits programs, providers, and descriptions.                                                                 |
| Groups            | Organizes employees into logical groupings such as departments, teams, and cost centers.                                                           |
| Jobs              | Represents job positions available within the organization, including titles and statuses.                                                         |
| Time Entries      | Records employee work time entries, including start and end times, breaks, and status.                                                             |
| Work Eligibility  | Tracks employee work authorization documents such as visas, passports, and other legal identification.                                             |
| Documents         | Manages employee-related documentation including personal identification, contracts, and administrative forms.                                     |
| Skills            | Represents employee professional skills, proficiency levels, and related attributes.                                                               |

## Use cases

<CardGroup cols={3}>
  <Card title="User Syncing" href="/hris/use-cases/sync-users">
    Ensure your system is up to date with all the employees details in your customers' HRIS system.&#x20;
  </Card>

  <Card title="Automated Employee Provisioning" href="/hris/use-cases/employee-provisioning">
    After the recruitment process, automate the provisioning and management of employees in your customer's HRIS system.
  </Card>
</CardGroup>