ADP APIConnect ADP without building on its API
ADP has a REST API. Not self-serve: partners must join ADP Marketplace, and Workforce Now customers must buy the ADP API Central add-on to build their own integrations. If you're reading the docs because you need ADP to talk to the rest of your stack, Caddi does that without you writing or maintaining integration code: you show it the job once, and it runs it across ADP and your other tools.
- APIREST (JSON)
- AuthOAuth 2.0 client credentials
- AccessApproval or paid add-on
What the ADP API gives you
- Type
- REST (JSON)
- Authentication
- OAuth 2.0 client credentials plus a mutual TLS (mTLS) certificate on every call
- Who can get access
- Not self-serve: partners must join ADP Marketplace, and Workforce Now customers must buy the ADP API Central add-on to build their own integrations.
- What it covers
- HR and payroll data such as workers, onboarding, job requisitions and applications, and pay data, listed in the Workforce Now API catalog.
Official docs: developers.adp.com. Checked September 2026. Vendors change access terms, so confirm with ADP before you build.
Building on the ADP API vs. having Caddi run it
| The job | Build it on the API | With Caddi |
|---|---|---|
| Getting access | Register an app, get ADP credentials, and manage tokens and refreshes. | Connect your ADP account once. Caddi holds the connection. |
| Writing the integration | A developer maps fields, handles pagination, retries and rate limits, and writes the sync. | You show Caddi the ADP task the way you'd train a new hire. It writes verified code for it. |
| Steps the API doesn't cover | Screens with no endpoint stay manual, or need a separate RPA tool. | Caddi uses a secure, audited browser session where there's no API, in the same automation. |
| The other systems in the loop | Each extra tool is another API, another set of credentials, another integration to own. | One automation runs across all the tools the job touches. |
| Keeping it running | Someone owns the code when the API version, fields or your process change. | Every automation is reviewed before it runs in production, and every run is logged. |
Building on the API is the right call when you have engineers and the integration is your product. When the goal is getting ADP work off someone's desk, the build is the slow part.
What teams usually want the ADP API for
New-hire onboarding
Caddi takes a signed offer or HRIS record and sets up the employee in ADP, then files the paperwork and notifies the manager.
Payroll prep & reconciliation
Caddi assembles hours, PTO, and adjustments ahead of each run, validates against source systems, and hands a clean file to payroll for review.
Payroll journal to accounting
After each run, Caddi writes the matching payroll journal entries to the accounting system with the right coding.
ADP API questions
Does ADP have an API?
Yes. ADP has a REST API, authenticated with OAuth 2.0 client credentials plus a mutual TLS (mTLS) certificate on every call. The official documentation is at https://developers.adp.com/.
How do I get access to the ADP API?
Not self-serve: partners must join ADP Marketplace, and Workforce Now customers must buy the ADP API Central add-on to build their own integrations.
Can I connect ADP to my other tools without writing code against its API?
Yes. With Caddi you show the ADP task once, the way you'd train a new hire, and Caddi builds it as verified code that runs across ADP and the other tools the job touches. Where a step has no API, Caddi uses a secure, audited browser session in the same automation.
Do I need a developer to automate ADP with Caddi?
No. There is no integration code for you to write or maintain. Every automation Caddi builds for ADP is reviewed before it runs in production, and every run is logged.
Connect ADP without the build.
Drop your work email and pick a time. We'll show you Caddi running your ADP workflow end to end.