Assay

agent402.tools

Utilities514 endpointsagent402.tools

Cryptographic hash of a text string. Algorithms: sha256 (default), sha512, sha1, md5. Returns hex and base64 digests.

Pays to C7IIHG7SPLPZ5H7ZT6HW3UV2OQMQQE6Y2HBNGZXSLRJULE42BEE2OY2XIE

Pays elsewhere2 rerouted · 23h ago2 above list8 of 514 failing
$0.001 – $1.50
USDC
Score
None yetno buyer reviews yet
Positive
None yetno buyer reviews yet
Paid calls
2,0894 distinct payers
Verified
23h ago506 of 514 as listed
On-chain
C7IIHG7S…OY2XIEpayout address on Algorand
All514With a finding8Free with proof of work12

514 of 514 endpoints

  • GET

    /api/ulid

    Generate ULIDs (sortable, timestamp-prefixed identifiers). ?count=1..100.

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/unit-convert

    Convert a value between units of length, mass, temperature, volume, area, speed, time, data, pressure, energy, power, angle, frequency — every unit the retired convert-* endpoints handled (e.g. miles, kilograms, us-gallons, fahrenheit, psi, kilowa...

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/url-code

    Percent-encode or decode a string for URLs. mode: encode (default) or decode. component: true (default) uses encodeURIComponent semantics.

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/url-parse

    Parse a URL into components: protocol, host, port, path, query params (decoded), hash, origin, punycode hostname.

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/user-agent

    Heuristic user-agent string parser: browser, version, OS, device class, and bot detection.

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • GET

    /api/uuid

    Generate UUIDs. ?version=4 (default, random) or 7 (time-ordered), ?count=1..100.

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/uuid-v5

    Generate a deterministic name-based UUID (version 5, SHA-1) from a namespace + name — the same inputs always yield the same UUID, for stable IDs without a database. Namespace may be a UUID or an alias: dns | url | oid | x500.

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/uuid-validate

    Validate a UUID and report its version (1-8) and variant. Accepts hyphenated or braced forms.

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/webhook-verify

    Verify a webhook's HMAC signature against the correct per-provider scheme: GitHub (X-Hub-Signature-256, sha256=hex), Stripe (Stripe-Signature t/v1 over "<t>.<body>" with replay tolerance), Shopify (X-Shopify-Hmac-Sha256, base64), Slack (X-Slack-Si...

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/word-frequency

    Top N words and bigrams from text. Lowercase, strip punctuation, filter common English stop words. Returns sorted word and bigram frequency lists.

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/word-wrap

    Wrap text to a specified column width, breaking at word boundaries. Words longer than the width are forcibly broken. An optional indent string is prepended to each line. Deterministic, pure CPU.

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • GET

    /api/workday-count

    Count business days (weekdays) between two dates, optionally excluding US federal holidays (MLK, Presidents Day, Memorial Day, Juneteenth, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving, Christmas, New Year). ?start=2026-01-...

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/xml-validate

    Check XML well-formedness: balanced open/close tags, proper nesting, unescaped entities. No DTD/schema validation — syntax only. Pure CPU, deterministic.

    as listed23h agoagent402.tools

    $0.001
    per call, USDC
    Try it
  • POST

    /api/a2a-card-validate

    Validate an A2A (Agent2Agent protocol) Agent Card: required fields, skill shape, transport names, capability flags — spec v0.3 structural core. Returns errors, interop warnings, and a normalized summary (skills, interfaces, capabilities). Determin...

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Try it
  • POST

    /api/address-label

    Label a known EVM address from a curated, committed dataset: major stablecoin + token contracts (USDC on every chain we settle on, USDT, DAI, WETH, WBTC), DEX routers (Uniswap, 1inch, 0x), canonical L1↔L2 bridges, large exchange hot/cold wallets, ...

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Open below

    Call it from here

    POST /api/address-label

    Assay builds the request this listing describes, sends it, and shows you exactly what comes back — including when what comes back is a complaint.

    The request, built from the listing

    POST https://agent402.tools/api/address-label

{"address":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"}

    Declared inputsaddress

    Listed at $0.002. If it demands payment, you will see its live terms — this site cannot settle them.

    This page holds no key and cannot move money. Paid verification runs in an isolated worker with the only signing account, under the spend ceiling published in the methodology.

  • GET

    /api/b20-activation-check

    Is B20 live on Base mainnet? Queries the Activation Registry precompile for base.b20_asset and base.b20_stablecoin (or a custom feature id). Honest pre-launch too: reports not-activated until the registry flips. ?feature=base.b20_asset (optional)

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Try it
  • POST

    /api/black-scholes

    Price a European option (call or put) with the Black-Scholes-Merton model, plus the greeks (delta, gamma, vega, theta, rho). Continuous dividend yield supported. Greeks are per unit: theta is per year, vega per 1.00 change in volatility, rho per 1...

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Try it
  • GET

    /api/block-info

    Header-level detail for one block on Ethereum, Base, Polygon, Arbitrum, or Optimism: hash, timestamp (unix + ISO), transaction count, gas used/limit, base fee. Pass a block number, 0x hex, or "latest". Keyless multi-endpoint failover. ?block=lates...

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Try it
  • POST

    /api/bond-ytm

    Solve a bond's yield to maturity from its market price — the annual rate that present-values the coupons plus face to that price. Bracketed bisection root-find.

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Try it
  • POST

    /api/calc

    Safely evaluate an arithmetic expression (+ - * / % ^ and parentheses). No code execution — a real parser, not eval.

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Try it
  • POST

    /api/captcha-verify

    Validate a Cloudflare Turnstile, Google reCAPTCHA, or hCaptcha token server-side. You pass your OWN provider secret plus the token from the client; we relay to the provider's siteverify endpoint (never logged) and return the normalized verdict (su...

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Try it
  • POST

    /api/cidr

    Parse an IPv4 CIDR block: network address, broadcast, first/last host, netmask, and host count. Optionally test if an IP is inside it.

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Try it
  • POST

    /api/compound-interest

    Compute future value of a principal under compound interest. Returns future value, total interest earned, and the effective annual rate (APY) given the compounding frequency. Matches Excel's FV(rate, nper, 0, -principal) and the classic (1+r/n)^(n...

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Try it
  • GET

    /api/contract-code

    Is this address a contract, and what code does it hold? Returns isContract, deployed bytecode size, and the keccak-256 hash of the bytecode (stable fingerprint for comparing deployments) on Ethereum, Base, Polygon, Arbitrum, or Optimism. Keyless m...

    as listed23h agoagent402.tools

    $0.002
    per call, USDC
    Try it

Buyer reviews

none yet · a review costs a settlement

Nobody has bought from agent402.tools through an address that came back to write about it. Rather than print an empty box, this page hands the position to the evidence it does have — Assay’s own verification record, immediately below.

  1. 01

    Pay the merchant

    Call one of their endpoints and settle the 402 challenge in USDC on Algorand mainnet. That transfer is the whole credential.

  2. 02

    Sign the settlement

    Connect the address that sent it and sign a message naming this merchant, that transaction and your score. Assay stores no account and no password.

  3. 03

    The receipt travels with it

    Your review renders with its transaction id linked to the public explorer, so anyone can re-derive that you were a customer. One settlement buys one review.

Assay’s own prober is barred from reviewing, and the exclusion is a row in the database rather than a claim in a footer. Own this payout address? Claim the listing

Verification record

last sweep 23h ago · 514 of 514 covered

Nobody has reviewed agent402.tools yet — a review attaches to a payout address and opens once a buyer has settled with it, because a settlement is the only thing that proves a reviewer was a customer. Until then this is the evidence Assay has: calls it made itself, and what came back.

What the last sweep found

answered as listed
506 answered as listed
answered, but not as listed
8 answered, but not as listed
  • Pays elsewhere2 endpoints
    • /api/route/execute
    • /api/route/execute-max
  • Price mismatch6 endpoints
    • /api/stock-quotelists $0.01, demands $0.003
    • /api/skill/domain-intellists $0.25, demands $0.075
    • /api/answerlists $0.03, demands $0.08
    • and 3 more

List every endpoint with a finding · checked 23h ago

Settled payments

Delivered for free, on proof of work

12 of this merchant’s endpoints accept a few milliseconds of CPU instead of money. Assay solved the puzzle and got real content back, which turns “it challenged for payment” into “it actually delivers” at no cost — and you can reproduce it from the endpoint list.

List the 12 you can call for nothing

Also in utilities

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