15 ATS APIs to Integrate With in 2026: Greenhouse, Lever, Workable

March 11, 2026

Updated June 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.

This guide covers 15+ ATS APIs developers commonly integrate with, the challenges of building recruiting integrations, and how a unified ATS API simplifies integration across dozens of recruiting systems.

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 expose 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 platforms depend on it to power recruiting workflows.

Why SaaS products integrate with ATS APIs

Recruiting integrations enable automation across hiring workflows. Common use cases:

• Recruiting analytics and reporting — pull 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 check automation — trigger 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

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, and recruiting activity. 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, and pipeline stages. Lever integrations often power sourcing automation and recruiting CRM tools.

Workable API

Widely used by SMBs and mid-market companies. Its APIs expose candidate applications, job postings, recruiting stages, interview scheduling, and hiring-team assignments. Workable is frequently integrated into interview platforms and recruiting analytics tools.

iCIMS API

A large enterprise recruiting platform used by global organizations. Typical capabilities include candidate records, hiring workflows, job requisitions, interview management, and recruiting reports. iCIMS integrations often require enterprise access.

SmartRecruiters API

Enterprise recruiting infrastructure. Common capabilities include job posting distribution, candidate pipelines, interview scheduling, hiring workflows, and recruiting analytics.

Jobvite API

Recruiting automation and talent acquisition tools. Its APIs support candidate management, recruiting workflows, job requisitions, and applicant pipelines.

JazzHR API

Focused on SMB recruiting teams. Typical integrations include candidate applications, job listings, hiring pipelines, and interview scheduling.

Ashby API

A modern ATS built API-first. Common integrations include recruiting analytics, sourcing automation, interview scheduling, and pipelines. Ashby is increasingly popular with startups.

BreezyHR API

Recruiting automation and candidate pipeline tools. Its APIs enable job management, candidate tracking, interview scheduling, and recruiting workflows.

Teamtailor API

Recruiting tools used heavily in Europe. Common integrations include job postings, candidate pipelines, recruiting automation, and hiring analytics.

Workday Recruiting API

Workday provides recruiting infrastructure alongside HR and payroll. Its recruiting APIs expose job requisitions, candidate applications, hiring pipelines, and recruiting workflows.

Oracle HCM API

Oracle's HCM recruiting capabilities (the platform formerly known as Taleo) remain widely used by large enterprises. Common integrations include candidate applications, recruiting pipelines, and hiring workflows.

Additional ATS platforms

Many other ATS platforms are commonly integrated by SaaS products, including Recruitee, RecruitCRM, Manatal, Loxo, Pinpoint, Tribepad, and Vincere. The recruiting ecosystem is highly fragmented, so supporting customers often means 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, 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 — 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 quickly.

The role of a unified ATS API

To reduce this complexity, many SaaS platforms adopt a unified ATS API that standardizes recruiting data models and authentication across multiple ATS providers.

Instead of building separate integrations for Greenhouse, Lever, Workable, Jobvite, and dozens of others, you integrate once and support many recruiting systems. A unified API typically provides normalized candidate and job data models, consistent authentication, standardized endpoints, unified webhooks, and ongoing handling of vendor API changes — which substantially reduces integration maintenance.

Build once with the Unified.to ATS API

The Unified.to ATS API provides access to recruiting data across 85+ ATS integrations through a single API, normalizing hiring data across platforms like Greenhouse, Lever, Workable, SmartRecruiters, and many others.

Unified.to ATS data objects

Recruiting data fetched live from the source

Unified.to uses a real-time pass-through architecture: every request is routed directly to the underlying ATS. That means no cached candidate data, no scheduled sync jobs, and pipeline data that reflects the source at the moment you call it.

No data stored at rest

Unified.to does not store candidate data. Requests are stateless and routed directly to ATS providers, which reduces compliance scope for platforms handling sensitive recruiting information.

Final thoughts

ATS APIs power modern recruiting software, from sourcing tools to analytics platforms. But integrating recruiting platforms individually quickly becomes a complex engineering challenge, and as the ecosystem grows, many SaaS companies adopt a unified ATS API to support dozens of recruiting systems through one integration layer.

If your product connects to recruiting tools, the Unified.to ATS API lets you support Greenhouse, Lever, Workable, and many other ATS platforms without maintaining separate integrations for each provider.

Start a free 30-day trial or book a demo.