Create a new user (individual or business) in the system.

Verification Modes:

Use verification_mode in the request body to choose how KYC/KYB is collected:

• automatic (default) — Send a complete payload and Kira triggers KYC/KYB in the background.
• verification_link — Send a minimal payload and Kira returns a hosted link the end user follows to complete KYC/KYB. Only first_name, last_name, email are required for individuals; only business_legal_name, email for businesses. An optional redirect_uri controls where the user lands after submission.

Automatic Verification flow:

1. No additional API calls needed — verification starts as soon as required fields are present.
2. Webhook notifications — you'll receive user.verification.accepted or user.verification.failed events.
3. The response includes a verification_triggered boolean indicating whether verification was actually started.

Eligibility model:

Kira evaluates the user against every active product and triggers verification as soon as at least one product has all of its required fields. Two virtual-account products are currently supported, each with different requirements:

• usa-virtual-accounts (Diameter) — Powered by the Diameter provider (PORTAGE for USA, SLOVAK_SAVINGS_BANK for international). Requires Government ID images and uploaded supporting documents (proof of address, source of wealth, business formation).
• usa-virtual-accounts-act (ACT) — Lighter onboarding via Austin Capital Trust. No photo documents required at create time (they are uploaded separately). Requires extra immigration / employment / banking-history fields instead.

Required-field lists are evaluated per category, derived from the user's address_country (and nationality / formation_country as fallback): usa_individual, international_individual, usa_business, international_business.

Required Fields — usa-virtual-accounts (Diameter):

USA Individual (usa_individual):

• Identity: first_name, last_name, birth_date, email, phone, nationality
• Address: address_street, address_city, address_state, address_zip_code, address_country
• Government doc (flat): document_type, document_number, document_country
• Tax ID: ssn (sent flat, or as identifying_information[].type = "ssn")
• Document files in identifying_information[].documents[]: front, back (required unless document_type = passport), file_proof_of_address, file_source_of_wealth

International Individual (international_individual):

• Same as USA Individual, except ssn is not required. A non-USA tax ID may be supplied via identifying_information (curp, rfc, cpf, tin, tax_id, etc.) but is not enforced for KYC triggering.

USA Business (usa_business):

• Business identity: business_legal_name, doing_business_as, business_type, business_industry
• Formation: formation_date
• Contact: email, phone
• Address: address_street, address_city, address_zip_code, address_country (note: address_state is NOT required for businesses)
• Government doc: document_number
• Tax ID: ein
• Business files in identifying_information[].documents[]: file_proof_of_address, file_business_formation, file_source_of_wealth
• At least one entry in associated_persons[], each with identifying_information[].documents[] containing front (always) and back (unless document_type = passport)

International Business (international_business):

• Same as USA Business, except ein is not required.

Required Fields — usa-virtual-accounts-act (ACT):

USA Individual (usa_individual):

• first_name, last_name, birth_date, email, phone, nationality
• address_street, address_city, address_state, address_zip_code, address_country
• document_type, document_number
• ssn
• employment_status, plus current_employer only when employment_status = employed

International Individual (international_individual):

• first_name, last_name, birth_date, email, phone, nationality
• address_street, address_city, address_state, address_zip_code, address_country
• document_type, document_number, document_country
• immigration_status
• additional_info.has_us_bank_account, additional_info.has_denied_bank_account
• employment_status, plus current_employer when employment_status = employed

USA Business (usa_business):

• business_legal_name, email, formation_date, formation_country, business_type
• address_street, address_city, address_state, address_zip_code, address_country
• ein
• associated_persons[] with: first_name, last_name, birth_date, email, nationality, document_number, and ssn unless the AP's nationality is non-US

International Business (international_business):

• business_legal_name, email, formation_date, formation_country, business_type
• address_street, address_city, address_state, address_zip_code, address_country
• associated_persons[] with: first_name, last_name, birth_date, email, nationality, document_number, document_country
• international_entity_type
• additional_info.has_us_bank_account, additional_info.has_denied_bank_account

Restricted Countries:

Users whose address_country is one of the following (ISO 3166-1 alpha-3) are blocked from virtual-account products: AFG, BLR, MMR, CAF, CIV, CUB, COD, IRN, IRQ, LBR, LBY, PRK, RUS, SAU, SOM, SDN, SYR, UKR, YEM, VEN, ZWE.

Authentication: Both x-api-key header and Authorization: Bearer <token> header are required.