15 ATS APIs to Integrate With in 2026: Greenhouse, Lever, Workable
March 11, 2026
Applicant Tracking Systems (ATS) sit at the center of modern hiring infrastructure. They manage candidate pipelines, job postings, applications, interview scheduling, and recruiting analytics.
For SaaS platforms building recruiting tools, HR analytics products, background check services, sourcing platforms, or interview tools, integrating with ATS systems has become essential.
But integrating ATS systems is rarely simple.
Every recruiting platform exposes a different API structure, authentication system, webhook model, and hiring pipeline schema. Supporting multiple ATS providers quickly becomes a major engineering burden.
In this guide we'll cover 15+ ATS APIs developers commonly integrate with, the challenges of building recruiting integrations, and how unified ATS APIs simplify integration across dozens of recruiting systems.
What Is an ATS API?
An ATS API allows software applications to programmatically access recruiting and hiring data stored inside an applicant tracking system.
These APIs typically expose endpoints for:
- candidates
- job postings
- applications
- interviews
- recruiting activities
- resumes and documents
- hiring scorecards
- recruiting pipelines
ATS APIs enable SaaS products to build features such as:
- candidate sourcing tools
- recruiting analytics dashboards
- interview scheduling platforms
- background check automation
- recruiting CRM systems
- recruitment marketing tools
Because ATS systems act as the system of record for hiring data, many SaaS platforms depend on them to power recruiting workflows.
Why SaaS Products Integrate with ATS APIs
Recruiting integrations unlock powerful automation across hiring workflows.
Common use cases include:
Recruiting analytics and reporting
Pull candidate pipeline data to measure time-to-hire, conversion rates, and recruiter performance.
Candidate sourcing tools
Automatically push sourced candidates into a company's ATS pipeline.
Interview scheduling platforms
Coordinate interviewer availability and update interview events inside the ATS.
Background check automation
Trigger background checks when candidates reach specific hiring stages.
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.
As recruiting stacks expand, ATS integrations become critical infrastructure.
15+ ATS APIs Developers Integrate With
Below are some of the most commonly integrated ATS APIs used by SaaS products today.
Greenhouse API
Greenhouse is one of the most widely used enterprise ATS platforms.
Its APIs provide access to:
- candidate profiles
- applications and job pipelines
- interview scheduling
- scorecards and feedback
- recruiting activity tracking
Greenhouse integrations are common for recruiting analytics platforms and sourcing tools.
Lever API
Lever provides recruiting CRM functionality alongside traditional ATS capabilities.
Its API supports:
- candidates and opportunities
- job postings
- interview scheduling
- candidate communications
- recruiting pipeline stages
Lever integrations often power sourcing automation and recruiting CRM tools.
Workable API
Workable is widely used by SMBs and mid-market companies.
Its APIs expose:
- candidate applications
- job postings
- recruiting stages
- interview scheduling
- hiring team assignments
Workable is frequently integrated into interview platforms and recruiting analytics tools.
iCIMS API
iCIMS is a large enterprise recruiting platform used by global organizations.
Typical integration capabilities include:
- candidate records
- hiring workflows
- job requisitions
- interview management
- recruiting reports
iCIMS integrations often require enterprise access.
SmartRecruiters API
SmartRecruiters provides enterprise recruiting infrastructure.
Common API capabilities include:
- job posting distribution
- candidate pipelines
- interview scheduling
- hiring workflows
- recruiting analytics
Jobvite API
Jobvite offers recruiting automation and talent acquisition tools.
Its APIs support:
- candidate management
- recruiting workflows
- job requisitions
- applicant pipelines
JazzHR API
JazzHR focuses on SMB recruiting teams.
Typical integrations include:
- candidate applications
- job listings
- hiring pipelines
- interview scheduling
Ashby API
Ashby is a modern ATS built with an API-first architecture.
Common integrations include:
- recruiting analytics
- sourcing automation
- interview scheduling
- recruiting pipelines
Ashby is becoming increasingly popular with startups.
BreezyHR API
BreezyHR offers recruiting automation and candidate pipeline tools.
Its APIs enable:
- job management
- candidate tracking
- interview scheduling
- recruiting workflows
Teamtailor API
Teamtailor provides recruiting tools used heavily in Europe.
Common integrations include:
- job postings
- candidate pipelines
- recruiting automation
- hiring analytics
Workday Recruiting API
Workday provides recruiting infrastructure alongside HR and payroll.
Its recruiting APIs expose:
- job requisitions
- candidate applications
- hiring pipelines
- recruiting workflows
Oracle Taleo API
Oracle Taleo remains widely used by large enterprises.
Common integrations include:
- candidate applications
- recruiting pipelines
- hiring workflows
Additional ATS Platforms
Many other ATS platforms are commonly integrated by SaaS products, including:
The recruiting ecosystem is highly fragmented, which means supporting customers often requires integrating dozens of ATS platforms simultaneously.
Challenges When Integrating ATS APIs
Integrating recruiting platforms directly introduces several engineering challenges.
Different authentication systems
Some ATS platforms use OAuth while others rely on API keys or enterprise authentication flows.
Inconsistent candidate data models
Candidate records, applications, and pipeline stages vary widely between vendors.
Webhook and event differences
Some platforms support real-time webhooks while others require polling.
API version changes
Recruiting platforms frequently update APIs and deprecate endpoints.
Compliance and candidate data
Candidate records often include sensitive personal information that must be handled securely.
As companies support more ATS integrations, this complexity grows exponentially.
The Role of Unified ATS APIs
To reduce integration complexity, many SaaS platforms adopt Unified ATS APIs.
A unified API standardizes recruiting data models and authentication across multiple ATS providers.
Instead of building separate integrations for Greenhouse, Lever, Workable, Jobvite, and dozens of others, developers integrate once and support many recruiting systems.
Unified APIs typically provide:
- normalized candidate and job data models
- consistent authentication flows
- standardized endpoints
- unified webhooks
- automatic handling of vendor API changes
This dramatically reduces integration maintenance.
Build Once with the Unified ATS API
The Unified ATS API allows developers to access recruiting data across 73+ ATS integrations through a single API.
Unified normalizes hiring data across platforms like Greenhouse, Lever, Workable, SmartRecruiters, and many others.
Unified ATS Data Objects
Unified provides standardized recruiting objects across all ATS platforms:
Candidates
Applicant profiles and recruiting information.
Jobs
Job postings and requisitions.
Applications
Candidate submissions to jobs.
Interviews
Interview schedules and interviewer assignments.
Activities
Notes, communications, and recruiting interactions.
Scorecards
Interview feedback and evaluation forms.
Documents
Resumes, cover letters, and attachments.
Companies
Organizations related to recruiting workflows.
Each object supports consistent methods:
- create
- list
- retrieve
- update
- remove
This allows SaaS products to build recruiting features once and support dozens of ATS providers.
Real-Time Recruiting Data
Unified uses a real-time pass-through architecture.
Every request is routed directly to the underlying ATS system.
This means:
- no cached candidate data
- no scheduled sync jobs
- real-time pipeline updates
- instant recruiting workflow automation
Zero-Storage Architecture
Unified never stores candidate data.
All requests are stateless and routed directly to ATS providers.
This architecture reduces compliance scope for platforms handling sensitive recruiting information.
Final Thoughts
ATS APIs power modern recruiting software, enabling everything from sourcing tools to recruiting analytics platforms.
However, integrating recruiting platforms individually quickly becomes a complex engineering challenge.
As the recruiting ecosystem continues to grow, many SaaS companies are adopting Unified ATS APIs to simplify integrations and support dozens of recruiting systems through a single integration layer.
If your product connects to recruiting tools, unified APIs make it possible to support Greenhouse, Lever, Workable, and many other ATS platforms without maintaining separate integrations for each provider.