Comparing Japanese ATS APIs for AI Agents — Only HERP Hire, Talentio, and Wantedly Hire (Read-Only) Are Usable Today

This post compares Japanese ATS public APIs through the lens of handing recruiting operations to an AI coding agent. The criteria are OpenAPI availability, auth and scope, write endpoints, documented rate limits, update cadence, and whether an official MCP server exists. As of 2026-09-14 only HERP Hire and Talentio (read-write) and Wantedly Hire (read-only) are usable right now; HRMOS Recruiting is at the announcement stage; sonar ATS is restricted to HRTech integration vendors and has paused new intake. I write up the per-vendor differences and the thin-CLI pattern I'd use to put any of them in an agent's hands.