Discover / creditcard.openverbs.com

Validate a card number

■ Challenge detected

Validate a payment-card number: Luhn check-digit test plus network detection and length check. A syntactically valid number that fails Luhn returns `valid:false` (a 200, not an error).

x402
Base
USDC

Listed price: $0.002
Challenge detected: 10 of the last 10 checks
Median response: 183 ms
Last checked: 17 Oct, 09:26 UTC
In our index since: 26 Sept 2026

Endpoint

curl -i https://creditcard.openverbs.com/v1/validate
# 402 Payment Required: pay with an x402 client (USDC on Base),
# then send the same request again with the payment attached.

5 listed endpoints · on x402 Bazaar

Checks and payment terms on this page refer to the endpoint above. Other listed endpoints have not been checked individually.

Base URLhttps://creditcard.openverbs.com/v1

POST/format$0.002Format a card number into the conventional display groups for its network (4-6-5 for Amex, 4-6-4 for 14-digit Diners, otherwise groups of four).
POST/validate$0.002Validate a payment-card number: Luhn check-digit test plus network detection and length check. A syntactically valid number that fails Luhn returns `valid:false` (a 200, not an error).
POST/generate$0.002Generate a random Luhn-valid TEST card number for the given network (default Visa). For testing only — these are not issued cards and cannot be charged. The response is always flagged `test:true`.
POST/network$0.002Detect the issuing network/brand (Visa, Mastercard, American Express, Discover, Diners Club, JCB, UnionPay, Maestro) from the card's IIN prefix, with the network's valid lengths. Returns `network:null` for an unrecognized prefix.
POST/mask$0.002Mask a card number for display, keeping the first six and last four digits (the PCI-permitted maximum) and replacing the rest with a mask character (default `*`).

A dash means the listing gives no price or method. Copy buttons copy the full URL.

Showing 5 of 5 listed endpoints.

Agents can find it through the Superstables MCP server and JSON API: GET /api/v1/services/creditcard.openverbs.com

Recent checks

2 Oct 2026One bar per check, showing up to 20 recent checks. Coloured bars show relative response time, with a minimum visible height; full-height grey bars mean no challenge was detected. “Challenge detected” means HTTP 402 or another detected payment-challenge signal.17 Oct 2026

All 10 checks

When (UTC)	Result	HTTP	Response
17 Oct, 09:26 UTC	Challenge detected	402	421ms
16 Oct, 13:59 UTC	Challenge detected	402	183ms
15 Oct, 08:20 UTC	Challenge detected	402	180ms
13 Oct, 22:50 UTC	Challenge detected	402	183ms
11 Oct, 22:04 UTC	Challenge detected	402	183ms
10 Oct, 10:04 UTC	Challenge detected	402	237ms
9 Oct, 03:33 UTC	Challenge detected	402	174ms
8 Oct, 00:44 UTC	Challenge detected	402	161ms
6 Oct, 21:30 UTC	Challenge detected	402	199ms
2 Oct, 05:04 UTC	Challenge detected	402	182ms

Questions

Did our last probe detect a payment challenge?

At our last probe on 17 Oct, 09:26 UTC, it returned HTTP 402 or another detected payment-challenge signal. This check did not test payment, delivery or compatibility with the Superstables client.

What price is recorded for Validate a card number?

Its listed price is $0.002.

What payment terms does Validate a card number advertise?

The listing advertises x402, Base and USDC. It names cdp as its facilitator. Check the seller's current payment challenge and authentication requirements before paying.

Where is Validate a card number listed?

In x402 Bazaar. Superstables first indexed it on 26 Sept 2026.

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