Your first result

Start with a check.
Build from there.

Try a sample without connecting a wallet. Then use the same service from your application or AI agent.

The first 5 calls per day are free, subject to the service allowance. Shared networks may share an allowance. Synthetic sandbox fixtures (such as GB82WEST12345698765432) evaluate free; real production counterparty identifiers and pack routes require x402 payment or a prepaid ck_live_ card key. Paid requests return payment instructions; this guide never submits a payment.

01 · Explore

See a real result

Open the checker, keep the sample IBAN, and select Run a check. Read the verdict and receipt returned by the service.

Open the sample checker →

A valid checksum confirms structure, not ownership or account existence.

02 · Connect

Bring your agent or app

Use the HTTP MCP endpoint or make a REST request. No private key belongs in a chat, configuration example, or this page.

Choose an integration →

Already building commerce? Check your protocol document.

Copy, run, inspect

One endpoint. Your preferred client.

REST · cURL

Run this sample from a terminal. It makes one API request.

curl -X POST 'https://hcrb.in/v1/tools/iban-check/call' \
  -H 'Content-Type: application/json' \
  -d '{"input":{"iban":"GB82WEST12345698765432"}}'

Windows PowerShell users: use curl.exe and put the command on one line.

MCP · Connect an AI client

Add this as a remote HTTP MCP server in a compatible client:

https://hcrb.in/mcp

For clients that accept a mcpServers configuration:

{
  "mcpServers": {
    "hcrb": { "url": "https://hcrb.in/mcp" }
  }
}

Client setup varies. Use a client supporting remote Streamable HTTP. View tool discovery.

JavaScript · Use fetch

const response = await fetch('https://hcrb.in/v1/tools/iban-check/call', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({ input: { iban: 'GB82WEST12345698765432' } })
});
console.log(response.status, await response.json());

Understand the next step

What happens after a request?

200 · Read the result

Inspect the returned validity, scope and signed receipt when supplied. A successful HTTP response alone does not mean an identifier is valid.

How to verify a receipt →

402 · Choose paid access

Dual-Rail Autonomous Settlement Active: Machines settle per call in Base L2 USDC / Circle EURC (x402 v2); operators and enterprise workflows purchase instant ck_live_ card quota keys or $99 batch audits via Stripe (Operated by JUANA LIMITED, UK Co. No. 14043409). Choose Operator Starter ($49/mo or £39/mo for 5,000 calls), Single Batch Exception Audit ($99 or £79 one-off for 2,000 rows), or Enterprise Corridor Guard ($499/mo or £399/mo for 75,000 calls).

Open instant Stripe card checkout (ck_live_) → · Compare access plans →

For other errors, inspect the response before retrying. Check service status or contact support with the request or receipt reference, never a private key.