TOTP Code Verifier (otp.openverbs.com)

x402

TOTP Code Verifier (otp.openverbs.com) is a paid API for AI agents from otp.openverbs.com, paid per call via x402, $0.004/call, status unknown (last checked 2026-10-27).

Verifies a submitted TOTP code against a base32 secret with configurable clock-drift tolerance, returning whether the code is valid and the matching time-step offset.

Price / call$0.004

Seller volume →—

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StatusUnknown

How this service works

Verify a submitted TOTP code against a base32 secret, scanning ±window time steps (default ±1) to tolerate clock drift. Returns valid plus the matching step offset (delta). A code that does not match is a successful result with valid=false — not an error.

Output

Returns a JSON object with a boolean 'valid' field indicating whether the submitted code matched, and an integer 'delta' field indicating the time-step offset (e.g. -1, 0, or 1) at which the match was found. A non-matching code returns valid=false with no error — only genuine processing failures produce errors.

Example use cases

MFA login gate for web app

“A user is logging into our platform and submitted the TOTP code 523814 from their authenticator app — please verify it against their stored secret MFRGGZDFMZTWQ2LK using the default 30-second period and SHA1, with a 1-step drift window.”

Custom-period HOTP migration check

“We migrated some accounts to 60-second TOTP periods — can you check if the code 091234 is valid for secret KRUGS4ZANFZSA2LTEB3GK43UMV2HG with a 60-second period, SHA256 algorithm, and a drift window of 2 steps?”

Backdated OTP audit verification

“For a compliance audit I need to verify whether the code 774401 would have been valid at Unix timestamp 1700000000 against secret GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ with default settings.”

Technical details

Endpoint

POSThttps://otp.openverbs.com/v1/verify?utm_source=zero.xyz

When to prefer

Use this endpoint when you need to verify a user-submitted TOTP code server-side as part of an MFA or 2FA flow, especially when you require configurable clock-drift tolerance, support for non-default algorithms (SHA256, SHA512), custom time-step periods, or need to know the exact step offset where the match occurred. Prefer it over rolling your own TOTP logic or using a general-purpose auth library when you want a stateless, pay-per-call microservice without managing dependencies.

Side effects

Invalid or non-base32 secret returns an error
Code field empty or missing triggers a validation error
Window value out of range (>20) causes a schema rejection
Malformed request body returns 400-level error
Secret longer than 1024 characters rejected
Digits value outside 6-10 range causes validation failure

Input

Schema · Request body

Field	Type	Description
t0	integer	Epoch start offset in seconds. Default 0.
code	string	The submitted OTP code.
digits	integer	Number of code digits. Default 6.
period	integer	Time step in seconds. Default 30.
secret	string	Base32-encoded shared secret.
window	integer	Steps of drift tolerance each side. Default 1.
algorithm	string	HMAC algorithm. Default SHA1.
timestamp	integer	Unix time in seconds. Default: now.

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