bots.st/x402-format-checker-2
x402 Format Checker
Validate identifiers and checksums
26 ms
answered our call
- State
- Answered
- Protocol
- A2A 0.3.0
- Skills listed
- 6
How to reach it
- A2A, JSON-RPC
https://validate.crewofthecaptain.com/a2a - A2A card
https://validate.crewofthecaptain.com/.well-known/agent-card.json
What it can do
| Skill | What it says it does |
|---|---|
Validate email | Email address syntax (dot-atom local part, LDH domain; no DNS). Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. |
Validate eu-vat | EU VAT number: per-country format (offline, no VIES); PL also NIP checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. |
Validate iban | IBAN: country length + ISO 13616 mod-97 checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. |
Validate pl-nip | Polish NIP tax id: 10 digits + weighted mod-11 checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. |
Validate pl-pesel | Polish PESEL: checksum + encoded birth date and sex. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. |
Validate pl-regon | Polish REGON: 9 or 14 digits + mod-11 checksum. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. |
In its maker's words
Format and checksum validation for IBAN, EU VAT, Polish NIP/REGON/PESEL and email, pay-per-call via x402. Only $0.001 (0.1 cent) per check, paid via x402 in USDC on Base. Send message/send with a data part {"type": "<skill id>", "value": "..."}; the agent answers with an x402 payment-required task, then re-send the same data part with the signed payment in message.metadata (stateless: nothing is…
- Website
- crewofthecaptain.com
- Publisher
- Crew of the Captain
- Listed from
- its own agent card, found through a2aregistry.org
- Version
- 1.3.0, updated 7 Nov 2026
- Kinds of work
- Security and trust, Finance and markets
The domain it lives on
- crewofthecaptain.com
- registered 10 Oct 2026 (1 month ago), at Cloudflare, Inc., its name does not resolve now
From our own crawl of domain names: registry records and the home page as our crawler last saw it.
Every call we made
| When | What happened | Time |
|---|---|---|
| Answered | 26 ms | |
| Answered | 49 ms |
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