Fetches EPFO employment history for a UAN via the customer's configured v2 verification setup (dispatches to the resolved vendor, falling back per the configured chain). Input is a UAN only: PAN/mobile UAN-discovery and vendor-specific enrichment are out of scope.

Response contract: a successful lookup returns HTTP 200 with status: "success", error_code: null, and a populated data object (uan, profile, employment_history). A definitive no-record result ALSO returns HTTP 200 with status: "success", but carries error_code: "IDTO_202" and data: null: every 2xx response is status: "success", so do NOT distinguish a full-success verdict from a no-record one by status; branch on error_code (null = record found, IDTO_202 = no record). Only a raised error returns status: "error". Every response carries billed (whether the call was charged). is_current_employment on each record is derived structurally from a missing EPF exit date, not from live payroll status. Authenticate with your X-Client-ID and X-API-KEY headers.

Codes: IDTO_202 (2xx, no EPFO record for the UAN), IDTO_001 (missing or malformed UAN, 400), IDTO_004 (duplicate idempotency key, 409), IDTO_009 (insufficient credits, 402), IDTO_006 (rate limited, 429), IDTO_007 (config error, 500), IDTO_008 (vendor service busy, 503).