01 / TL;DR
These solve different integration problems
Public ATS endpoints are the shortest path to one employer’s published jobs. Greenhouse describes its Job Board API as a JSON view of one company’s offices, departments, and jobs; Lever namespaces postings under a company site; Ashby exposes an organization’s currently published postings.
Clair sits one layer above that source diversity. It continuously reads validated public boards, normalizes comparable fields, retains provenance, and serves one cross-company search contract. You give up source-native completeness and write operations in exchange for not owning a fleet of provider adapters.
02 / SIDE BY SIDE
Where the engineering work lives
| Direct ATS APIs | Clair Job Search API | |
|---|---|---|
| Scope | One employer or ATS tenant per board identifier or credential set | One prepared search surface across supported public boards and ATS providers |
| Schema | Source-native fields and provider-specific naming | Normalized jobs, compensation, workplace, seniority, skills, time, and provenance fields |
| Freshness | You schedule requests, retries, removals, and provider health checks | Per-record verification time plus response-level index health and stale-board counts |
| Search | Whatever filtering or pagination each public board endpoint exposes | Cross-company structured filters and one query-bound cursor contract |
| Write access | Some authenticated ATS APIs support applications or recruiting workflows | None; read-only results link back to publisher-controlled application flows |
| Best fit | Employer-owned career sites, source-native workflows, or one known tenant | Job discovery, alerts, labor-market research, and multi-company ingestion |
Source behavior above follows the current official Greenhouse Job Board API, Lever Postings API, and Ashby public postings API documentation. Providers can change their contracts; verify the source you plan to maintain.
03 / DIRECT
Choose direct when source-native behavior is the product
A direct integration is clearer when you operate an employer’s career page, know the exact tenant, or need fields Clair does not normalize. It is also the only appropriate path for authenticated ATS workflows such as receiving applications or working with private recruiting data.
In that model, your team owns provider discovery, identifiers, pagination differences, retry policies, schema drift, deduplication, removals, and monitoring. That can be a good trade when fidelity to a small number of sources matters more than market breadth.
04 / INDEXED
Choose Clair when comparability is the product
Clair is shaped for products that ask one question across many employers: find newly discovered internships, compare stated salary bands, monitor remote roles, or maintain a research dataset. The same filters and cursor rules apply regardless of the source ATS.
Normalized does not mean inferred without limits. Missing fields stay null, compensation keeps its source and interval, and every result retains ATS, board, external ID, links, and verification time.
05 / HYBRID
A hybrid is often the honest architecture
Use Clair for discovery and cross-market filtering, then follow the publisher URL or call a direct source integration for the latest source-native detail. This keeps a broad catalog from pretending to be an applicant-tracking system.
The job-market data pipeline guide explains how to retain the time and provenance fields needed for that handoff.
06 / FAQ
Questions before choosing
Does Clair replace an ATS?
No. An ATS owns recruiting workflows, private records, applications, and the employer's source data. Clair is a read-only search index over public postings.
Can I submit applications through Clair?
No. Clair returns the publisher's posting and application URLs when available. Application submission remains with the employer or ATS.
When should I integrate an ATS directly?
Use a direct integration when you control the employer account, need source-native fields or write operations, or only need one known board. Use Clair when the product needs comparable search across many companies and providers.