Zero Auth

Quick Reference

WhatZero-value card validation

WhyConfirm a card is active without moving money

DifficultyBeginner

PrerequisitesAuthentication → Wallet

Zero-auth sends a non-monetary pre-authorization to the card network, confirming the card exists, is active, and can accept charges — without moving any funds.

Why zero-auth

Use case	Benefit
Subscription setup	Validate the card before the first billing cycle begins
Card-on-file	Confirm a stored card is still valid before a future charge
Fraud pre-check	Detect stolen or blocked cards at onboarding, not at checkout
Onboarding	Verify payment credentials during account creation

Endpoint

POST https://core-manager.a55.tech/api/v1/bank/wallet/zeroauth/

Postman: Import the A55 API Collection to test this endpoint interactively.

Request fields

Field	Type	Required	Description
`wallet_uuid`	string	Yes	Wallet identifier
`holder_name`	string	Yes	Name as printed on the card
`card_number`	string	Yes	Full PAN
`expiry_month`	string	Yes	Two-digit month
`expiry_year`	string	Yes	Four-digit year
`cvv`	string	Yes	Card verification value
`brand`	string	No	Card brand (auto-detected if omitted)

cURL
Python
JavaScript

curl -X POST https://core-manager.a55.tech/api/v1/bank/wallet/zeroauth/ \
  -H "Authorization: Bearer $TOKEN" -H "Content-Type: application/json" \
  -d '{"wallet_uuid":"wal_abc123","holder_name":"Jane Doe","card_number":"4111111111111111","expiry_month":"12","expiry_year":"2027","cvv":"123"}'

resp = requests.post("https://core-manager.a55.tech/api/v1/bank/wallet/zeroauth/",
    headers={"Authorization": f"Bearer {token}"},
    json={"wallet_uuid": "wal_abc123", "holder_name": "Jane Doe",
          "card_number": "4111111111111111", "expiry_month": "12",
          "expiry_year": "2027", "cvv": "123"})

const resp = await fetch("https://core-manager.a55.tech/api/v1/bank/wallet/zeroauth/", {
  method: "POST",
  headers: { Authorization: `Bearer ${token}`, "Content-Type": "application/json" },
  body: JSON.stringify({ wallet_uuid: "wal_abc123", holder_name: "Jane Doe",
    card_number: "4111111111111111", expiry_month: "12", expiry_year: "2027", cvv: "123" }),
});

Response examples

Valid card:

{ "status": "confirmed", "response_code": "00", "message": "Card is valid and active" }

Invalid card:

{ "status": "declined", "response_code": "14", "message": "Invalid card number" }

Zero-auth flow

Response codes

Code	Description	Action
`00`	Approved	Card is valid — proceed
`05`	Do not honor	Contact cardholder — issuer declined without specific reason
`14`	Invalid card number	Check for typos in the PAN
`51`	Insufficient funds	Not relevant for zero-auth — treat as valid card
`54`	Expired card	Request updated card details
`57`	Transaction not permitted	Card type does not support this operation
`62`	Restricted card	Card is flagged — do not proceed
`63`	Security violation	CVV mismatch — ask cardholder to re-enter
`76`	Invalid account	Account closed or non-existent
`79`	Lifecycle decline	Card was recently reissued — request new details
`N7`	CVV mismatch	Verify the CVV with the cardholder
`91`	Issuer unavailable	Retry after 30 seconds
`96`	System malfunction	Retry with exponential backoff
`389`	Fraud suspicion	Do not retry — flag for manual review
`500`	A55 internal error	Retry or contact support

Pair with tokenization

Combine zero-auth with tokenization: validate the card first, then tokenize it in the same flow. This ensures you only store tokens for cards that are confirmed active.

Card Tokenization →Store the validated card as a secure token Subscriptions →Set up recurring billing after validation Anti-Fraud →Enrich charges with device and behavioral signals

Quick Reference

Why zero-auth​

Endpoint​

Request fields​

Response examples​

Zero-auth flow​

Response codes​