I've been trying to setup a new ATS (Applicant Tracking System) automation for a recruiting agency, but one aspect we couldn't overcome:
The ATS provider doesn't give us the API keys. 😠 Hence, we can't connect from Claude or any other system and access candidate information from outside of the ATS.
The CEO got frustrated and considers switching the ATS/CRM system. This is how I think about ATS going forward… and my preferred ones below.
API over UI
(API = Application Programming Interface, UI = User Interface)
ATS systems usually have lots of features. You'll probably only use a fraction of them, but still you have to pay license fees no matter who of your recruiters use what features. This pricing model is broken and not sustainable with the advent of AI, agentic engineering, and custom applications.
To fully utilize the power of AI, agents need to be able to connect to your systems (ATS, CRM, email, etc.). They can connect either via MCPs (slow, expensive) or APIs (faster, cheaper).
I can imagine in 6-12 months most of your colleagues in the recruiting department will not even need to login to your ATS:
An AI agent invites best candidates for interviews
Another agent pre-screens candidates CVs and requests additional info
Another agent sources candidates in external databases
Your ATS essentially becomes an external database with fancy UI (which you don't need).
So what's most important?
API quality (so you can integrate)
License fees / TCO (so you don't pay for tons of features that you don't need)
APIs allow you to run your own automations, integrate with other systems, connect Claude or other AI agents, for example the autonomous sourcing agents at Calyflow.ai.
Focus on ATS with really good APIs that you can connect to (top left quadrant). I'd ignore the giant, expensive ATS providers with tons of features, most of which you'll never use.
Executive take
Best API-first shortlist: Ashby, Greenhouse, Recruitee, Pinpoint, Lever, Workable, SmartRecruiters, Teamtailor, JazzHR, Zoho Recruit.
Good but verify commercial/API tier: Recruit CRM, Loxo, JobAdder, Bullhorn, CEIPAL, TalentLyft, Comeet.
Not ideal: Vincere, Manatal, Jobvite, UKG, ADP Recruiting, and most heavy HCM-suite ATSs unless your company is already committed to that ecosystem.
ATS systems categorized
I have fresh and very positive experience with Ashby as I just finished a complex custom implementation in a trading company. Use the list below to choose yours:
🟢 Category 1: The Best Fits (Open APIs, Mid-Tier Access, No Approvals)
Ashby: Strong. My favorite; it worked really well on my most recent implementation (June 2026).
Teamtailor: Excellent. Full REST API access is included in their standard plans. No enterprise upgrade required.
Workable: Great. Available on the "Standard" plan (mid-tier). Not locked behind custom enterprise tiers.
Breezy: HR Great. Included in the "Growth" and "Business" tiers (standard SMB/mid-market plans).
Recruitee: Good. Available on their "Grow" plan (mid-tier).
Manatal: Excellent Value. API access is standard across their affordable tiers. Pinpoint Good. Open API access is standard in their core offering. Comeet Good. API access is available without requiring their top-flight custom enterprise plans.
Greenhouse: Borderline. Full API capability (Harvest API) is open, but you must be on their "Advanced" plan (mid-tier) rather than "Essential."
🟡 Category 2: Proceed with Caution (Mid-Tier, but High Friction or Technical Debt)
JazzHR: Highly affordable and API is available on mid-tiers, but the API looks dated, XML-heavy in places, and limited in write capabilities compared to modern REST interfaces.
BambooHR: If using it as an ATS, the API is open on standard tiers, but the data structure is built around HRIS records, making pure recruiting workflows clunky to build.
Rippling: Beautifully documented, but API access is deeply tied to their broader unified workforce platform. If you only want the ATS, it's an expensive ecosystem to buy into.
Zoho Recruit: Cheap and accessible, but their API API rate limits are heavily throttled on mid-tiers, forcing you to upgrade just for call volume.
ClearCompany: API is available, but documentation is notoriously difficult to get without contacting their support team.
Freshteam: Accessible on mid-tiers, but the API endpoints for deep recruitment customization are relatively shallow.
CEIPAL: Primarily for staffing; API is available but documentation is clunky and heavily geared toward legacy VMS systems.
Tracker: Solid staffing ATS, but setting up webhooks and custom REST streams requires coordination with their engineering team.
🔴 Category 3: Immediate Disqualifications (Locked Behind Enterprise or Requires Approvals)
The "Approval Required" Group (Friction & Gatekeeping)
Vincere: Requires partner ecosystem approval and manual verification. Really painful—we're not able to get it for a UK-based agency. ❌
Bullhorn: The industry giant for staffing, but obtaining REST API credentials requires submitting a developer request form, getting vetted, and waiting for manual provisioning.
Loxo: Excellent AI-sourcing ATS, but they strictly control their API access. You cannot simply generate a key; you have to go through an approval process with their team.
Jobvite: Legacy architecture. API keys must be requested through account managers and provisioned manually.
Avionté: Heavily locked down. API access requires formal partnership requests or paid professional services.
The "Enterprise-Only Paywall" Group (Most Expensive Tier)
SmartRecruiters: While their API is incredibly robust, access to full write-capabilities, custom fields, and real-time webhooks is strictly restricted to their high-end Enterprise Core packages.
Lever: To get full programmatic access to their developer ecosystem (LeverTRM), you are almost always pushed into their top-tier Enterprise packages or forced to pay for a high-cost "Advanced Tech" add-on package.
iCIMS: Extremely enterprise-focused. API integrations require paid implementation consultants and top-tier subscription scaling.
SAP SuccessFactors: Requires massive enterprise deployment and specialized integration cloud access.
Workday Recruiting: No standalone mid-tier exists. API access requires complex web services (WSDL) and massive enterprise contracts.
Oracle Taleo: Legacy enterprise tool; API access is complex, often requires middleware, and is restricted to enterprise-level tiers.
NEXT: Connect your ATS at Calyflow
Calyflow is a suite of next-generation, open-source AI recruiting agents.
If your ATS supports API integrations, GREAT! You can just copy-paste your API keys to Calyflow and run your first AI-powered autonomous sourcing agent.
If you need to migrate from one ATS to a new one, reach out and we'll discuss how to migrate the data.
