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otp.openverbs.com v1 hotp
https://otp.openverbs.com/v1/hotp
answers 402
Generate an RFC 4226 counter-based HMAC one-time password from a base32 secret and counter. Configurable digits (6–10, default 6) and algorithm (SHA1/SHA256/SHA512, default SHA1). An invalid base32 secret is a clean 400.
We sent a real
POST request to this endpoint and it
answered 402 with payment requirements we could parse.
- Price
- $0.004
- Network
- base
- Pay to
- 0xb3f4de103F34b99f0Da19B4F16D6B53a14C2194A
- Spec dialect
- v2 (declares x402Version 2)
- Transport
- PAYMENT-REQUIRED header
- HTTP method
- POST
- Response latency
- 271 ms
- Payment options
- 1 usable of 1
- Last checked
- 2026-09-06T01:20:12.242Z (23d ago)
- Category
- ai-inference
Re-check it yourself:
curl "https://api.the402.dev/validate?url=https%3A%2F%2Fotp.openverbs.com%2Fv1%2Fhotp"