Documentation Index
Fetch the complete documentation index at: https://docs.cryptomate.me/llms.txt
Use this file to discover all available pages before exploring further.
Overview
Cards is a virtual prepaid card product powered by cryptocurrency collateral. Designed for businesses, it uses stablecoins on Polygon as the backing asset: each card is linked to a stablecoin wallet, and funds are automatically converted to dollars at a 1:1 ratio, making integration with conventional payment networks seamless.Card specifications
- Brand: Visa
- Acceptance: Google Wallet and e-commerce platforms
- Security: Protected by 3DS to mitigate fraud
Operational models
Top Up
Users load funds directly onto the card through a dedicated deposit wallet created exclusively for this purpose.
External authorization
Your systems integrate via webhooks: for each transaction you have 1,200 ms to authorize or reject it based on your own approval logic.
Issuance and flexibility
Each business can issue as many cards as are available in their pack, enabling teams to scale deployment according to user demand.Holding wallet mechanism
A holding wallet backs every card transaction. A purchase only succeeds if the holding wallet has sufficient balance — otherwise the transaction is declined.Withdrawals
Funds can be withdrawn from the holding wallet to external accounts for independent use. A minimum balance is always locked to preserve capacity for at least one transaction, ensuring continuous payment capability.Why CryptoMate Cards
This solution combines the convenience of conventional cards with the flexibility of blockchain infrastructure, giving businesses a modern way to manage payments backed by crypto reserves.Webhooks
Cards is the most event-heavy product. Every authorization, clearing, refund, reversal, and card deposit is pushed to your webhook endpoint withproduct: "cards". Register a webhook URL and webhook_key from the Portal (or via the Subscribe webhook URL and Subscribe webhook key endpoints).
| Event | When it fires |
|---|---|
authorization | A transaction needs your approval. Respond within 1,200 ms with "00"/"SUCCESS" to approve or "05" to decline. |
authorized | A transaction was authorized by CryptoMate (external authorization not required or approved). |
cleared | An authorized transaction cleared and funds settled. |
declined | A transaction was declined (by your webhook response or by CryptoMate). |
reversal | A previously authorized transaction was reversed. |
refund | A merchant refund was applied to the card. |
deposit | A deposit arrived at the card’s top-up wallet. |
visa_direct_deposit | A Visa Direct deposit credited the card. |
warranty_withdraw | A withdrawal from the card’s warranty/holding balance completed. |
notification_3ds_authorization | A 3DS challenge was triggered for the cardholder. |
card_blocked_by_velocity | A card was automatically blocked after a velocity rule triggered. Sent once per ACTIVE → BLOCKED transition. |
X-Webhook-Key, the 1,200 ms deadline on authorization, and payload examples.
Velocity rules
Velocity rules let you define purchase rate limits at the account level to protect against fraud and card probing. Each rule specifies a maximum number of approved authorizations allowed within a sliding time window, applied per card. You can configure up to 5 rules per company. When any rule is triggered during an authorization, the transaction is declined and the card is automatically blocked until manually unblocked. Unblocking the card also resets its authorization counter, ensuring the card can resume normal operation immediately. If no rules are configured, no rate-limit validation is applied.| Rule field | Description |
|---|---|
max_authorizations | Maximum approved authorizations within the window (integer ≥ 1) |
time_window_seconds | Sliding time window duration in seconds (integer ≥ 1, unique per rule) |
card_blocked_by_velocity webhook to your endpoint so your systems can react in real time (alert the cardholder, open a fraud investigation, etc.).
Cards API reference
Explore endpoints for virtual cards, transactions, holding, and account configuration.