15 ATS APIs to Integrate With in 2026: Greenhouse, Lever, Workable
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The ATS APIs SaaS teams integrate with include Greenhouse, Lever, Workable, iCIMS, SmartRecruiters, Jobvite, JazzHR, Ashby, BreezyHR, Teamtailor, Workday Recruiting and Oracle Recruiting, plus a long tail such as Recruitee, RecruitCRM, Manatal, Loxo, Pinpoint, Tribepad and Vincere. This list is for teams building recruiting, sourcing, assessment, background-check and interview products: it covers what each vendor's API gives you and why integrating many of them is hard, since each ATS has its own authentication, object model, webhook support and pipeline stages.
To reach many of these through one integration, Unified.to's ATS API covers 162 ATS integrations; to compare unified API platforms for ATS, see Best Unified API for ATS Integrations in 2026.
What is an ATS API?
An ATS API lets software applications programmatically access recruiting and hiring data stored inside an applicant tracking system.
These APIs typically have endpoints for candidates, job postings, applications, interviews, recruiting activities, resumes and documents, hiring scorecards, and recruiting pipelines.
They enable SaaS products to build candidate sourcing tools, recruiting analytics dashboards, interview scheduling platforms, background check automation, recruiting CRM systems, and recruitment marketing tools. Because the ATS acts as the system of record for hiring data, many SaaS products depend on it for their recruiting features.
Why do SaaS products integrate with ATS APIs?
SaaS products integrate with ATS APIs because the ATS is the system of record for candidates, jobs and applications, so recruiting tools have to read from it and write back to it. Common use cases:
- Recruiting analytics and reporting: read pipeline data to measure time-to-hire, conversion rates, and recruiter performance.
- Candidate sourcing tools: add sourced candidates into a company's ATS pipeline.
- Interview scheduling platforms: coordinate interviewer availability and update interview events in the ATS.
- Background checks and assessments: start a check when a candidate reaches a stage, or list your packages inside ATSes that have an assessment module.
- Recruitment marketing: publish job postings to career pages and track candidate sources.
- AI recruiting assistants: analyze candidate profiles and recommend top candidates based on job requirements.
Which ATS APIs do developers integrate with?
Each entry below says what that vendor's API covers; other ATS platforms with APIs follow.
Greenhouse API
Greenhouse's Harvest API covers candidate profiles, applications and job pipelines, interviews, scorecards and recruiting activity; a separate partner-only Assessment API handles embedded tests (see 6 ATS assessment APIs).
Lever API
Lever provides recruiting CRM functionality alongside traditional ATS capabilities. Its API supports candidates and opportunities, job postings, interview scheduling, candidate communications, and pipeline stages.
Workable API
Workable's API covers candidate applications, job postings, recruiting stages, interview scheduling, and hiring-team assignments.
iCIMS API
iCIMS documents its APIs on the iCIMS Developer Community, which requires a login or an access request (as of 20 October 2026). Typical capabilities include candidate records, job requisitions and applicant pipelines.
SmartRecruiters API
SmartRecruiters' API covers job posting distribution, candidate pipelines, interview scheduling, hiring processes, and recruiting analytics.
Jobvite API
Jobvite's API covers candidate management, recruiting processes, job requisitions, and applicant pipelines.
JazzHR API
JazzHR's API covers applicants, jobs, applications to jobs, activity and files. As of 19 October 2026, Unified.to's JazzHR integration reads jobs, scorecards and documents, and reads and creates candidates and applications.
Ashby API
Ashby's API covers candidates, applications, jobs, interviews and pipelines, and Ashby runs a partner Assessments framework for skills tests, reference checks and background checks.
BreezyHR API
BreezyHR's API covers job management, candidate tracking, interview scheduling, and recruiting stages.
Teamtailor API
Teamtailor's API covers job postings, candidate pipelines, recruiting automation, and hiring analytics.
Workday Recruiting API
Workday provides recruiting infrastructure alongside HR and payroll. Its recruiting APIs cover job requisitions, candidate applications, hiring pipelines, and recruiting processes.
Oracle HCM API
Oracle Recruiting, part of Oracle Cloud HCM, is Oracle's current recruiting product, and Oracle offers Taleo customers a path to move to it (Oracle Recruiting). Common integrations include candidate applications, recruiting pipelines, and hiring processes.
Additional ATS platforms
As of 19 October 2026, Unified.to also integrates with Recruitee, RecruitCRM, Manatal, Loxo, Pinpoint, Vincere and Tribepad (beta). See the full ATS integration list. Access terms vary: as of 21 October 2026, Manatal enables its Open API by default on its Enterprise Plus plan and on request otherwise, Loxo's Open API is a paid feature, and Tribepad sets up its APIs for customers rather than offering them self-serve. The recruiting market is fragmented, so supporting your customers often means integrating many ATS platforms at once.
Assessment and background-check products also need the ATSes' separate partner APIs; 6 ATS assessment APIs compares them.
What makes ATS APIs hard to integrate?
ATS APIs are hard to integrate at scale because each vendor differs in authentication, data model, events and versioning:
- Different authentication systems: some ATS platforms use OAuth, others rely on API keys or enterprise auth flows.
- Inconsistent data models: candidate records, applications, and pipeline stages vary widely between vendors.
- Webhook and event differences: some platforms support native webhooks while others require polling.
- API version changes: vendors deprecate endpoints on their own schedules (Greenhouse deprecated assessment polling on 1 October 2019, for example).
- Compliance and candidate data: candidate records often include sensitive personal information that must be handled securely.
Each ATS you add is another set of these differences to build and maintain. For how teams handle them, and when to build versus buy, see ATS API Integration: Real-Time Recruiting Data, Candidate Pipelines, and Hiring Automation.
How do you integrate many ATS APIs at once?
To integrate many ATS APIs at once, teams use a unified ATS API: one data model and one authorization flow across many recruiting systems, instead of a separate build per vendor. Unified.to's ATS API covers 162 ATS integrations, including Greenhouse, Lever, Workable and SmartRecruiters; it reads from and writes to each source ATS at request time, with no customer records at rest. Its objects and per-integration field support are in the ATS API overview and the ATS integration list; to compare it with other unified API platforms, see Best Unified API for ATS Integrations in 2026.