Workday vs Workday Legacy — Why Unified.to Supports Both
July 22, 2025
Workday provides two main API integration formats:
- Workday REST API: Workday's newer API, still adding endpoints.
- Workday SOAP API (Workday Web Services, often called Legacy): the older API, which still covers objects and actions REST doesn't yet.
Unified.to supports both, as two integrations, Workday and Workday (Legacy), so you can use whichever covers the objects you need.
Why You Might Need Both
While Workday is steadily improving their REST API, there are still important gaps. Here's why using both makes sense today:
- Application create / list: Workday's REST API does not support job applications. List, get, create, and update are only available through the Legacy SOAP integration.
- Candidate updates: REST supports list, get and create for candidates (prospects), but updating candidates still requires Legacy.
- Create / update job: Creating and updating jobs still relies on the Legacy integration. REST supports list and get for job postings.
- ATS activity & application statuses: available on Legacy only today.
- Broader HRIS / payroll / payments coverage on Legacy: objects like HR benefit, deduction, bank account, location, payslip, taxonomy, job (positions), and Payment are Legacy-only. REST uniquely covers LMS content, accounting purchase orders, expenses and expense reports, HR earnings (with create/update/remove), projects and project tasks, Help cases (ticketing), and performance goals and feedback.
- Coverage changes: Workday keeps adding REST endpoints, so check each integration's Feature Support tab for current coverage.
The support matrix below shows Unified.to's coverage for Workday (REST) and Workday (Legacy) (SOAP), from the integration pages in the docs as of 27 October 2026.
| Workday (REST) | Workday Legacy (SOAP) | |
|---|---|---|
| ATS Activity | List, Get, Create | |
| ATS Application | List, Get, Create, Update | |
| ATS Application Status | List | |
| ATS Candidate | List, Get, Create | List, Get, Create, Update |
| ATS Company | List, Get | List, Get |
| ATS Document | List, Get, Create | List, Get, Create |
| ATS Interview | List, Get | List, Get, Create, Update |
| ATS Job | List, Get | List, Get, Create, Update |
| ATS Scorecard | List, Get, Create | List, Get, Create, Update |
| HR Attendance | List, Get | List, Get |
| HR Bank Account | List | |
| HR Benefit | List, Get | |
| HR Company | List, Get | List, Get |
| HR Deduction | List, Get, Create, Update | |
| HR Document | List, Get | List, Get |
| HR Earning | List, Get, Create, Update, Remove | |
| HR Employee | List, Get | List, Get, Create |
| HR Group | List, Get | List, Get, Create, Update |
| HR Job | List, Get | |
| HR Location | List, Get, Create, Update | |
| HR Payslip | List | |
| HR Taxonomy | List | |
| HR Timeoff | List, Get, Create, Update, Remove | List, Get, Create, Update |
| HR Timeshift | List, Get, Create, Update, Remove | List, Get |
| LMS Content | List, Get | |
| Accounting Bill | List, Get | List, Get, Remove |
| Accounting Contact | List, Get | List, Get, Create, Update |
| Accounting Invoice | List, Get | List, Get, Remove |
| Accounting Payment Term | List, Get, Create | |
| Accounting Purchase Order | List, Get | |
| Accounting Expense | List, Get, Remove | |
| Accounting Expense Report | List, Get, Create | |
| Payment | List, Get, Remove | |
| Performance Feedback | List, Create | |
| Performance Goal | List | |
| Task Project | List, Get | |
| Task | List, Get, Update, Remove | |
| Ticketing Category | List, Get | |
| Ticketing Customer | List, Get, Create | |
| Ticketing Note | List, Create | |
| Ticketing Ticket | List, Get, Create |
Frequently Asked Questions & Answers
Question: Do I have to send XML requests for Workday Legacy?
Answer: No! You always send JSON requests to Unified.to. We handle the conversion to XML behind the scenes for the SOAP API.
Question: Can I use both the REST and Legacy APIs at the same time?
A****nswer: Yes. Each is its own connection, so you can, for example, read documents through Workday (REST) and create applications through Workday (Legacy), both returning the same unified models.
Question: Is the Workday (Legacy) integration going to be deprecated?
Answer: The docs show no deprecation for Workday (Legacy) as of 19 October 2026, and it still covers objects the REST integration doesn't, such as applications, deductions and payslips.
Question: Is authentication different for Legacy vs REST?
Answer: Yes. Workday (REST) uses OAuth 2.0 with a client ID, client secret and refresh token. Workday (Legacy) uses an Integration System User (ISU): the integration page asks for the Workday host, tenant name, ISU username and ISU password, and the SOAP API receives them as a WS-Security UsernameToken inside the SOAP envelope rather than in an HTTP Authorization header. Unified.to handles both.
Question: Are the data models the same between REST and Legacy?
Answer: Yes. Unified.to maps both onto the same unified models, so an employee or a job has the same fields whichever Workday API is behind it. Which objects and methods each integration supports differs, as the table shows.
Question: Can I switch from Legacy to REST later?
Answer: Yes, object by object, as REST coverage grows. Because both integrations return the same unified models, your code for an object stays the same; what changes is which connection you call, and each connection needs its own authorization.
Question: Will using both cost more?
Answer: No. Unified.to prices by API call with unlimited connections, so a second Workday connection adds no fee of its own.
Which Workday integration should you use?
Workday is moving more features to its REST API, but some objects and actions are still available only through the SOAP-based Legacy API, so Unified.to supports both.
Our recommendation: Use the Workday (REST) integration wherever it covers your workflow (including time off writes, earnings, LMS, purchase orders, expenses, projects and tasks, Help cases, and performance goals and feedback), and use Workday (Legacy) for gaps such as applications, candidate updates, job create/update, broader HRIS/payroll objects, and payments. Unified.to handles each API's authorization and format, including converting your JSON requests to SOAP for Legacy.
Have more questions?
Reach out to our support team for help choosing between the two Workday integrations.