61trust / 100

Distribution Table

by Probability Calculators in Other

x402 APIPassing, checked 5 h ago

Exact pmf, cumulative and tail tables for geometric, negative binomial, hypergeometric, binomial and Poisson.

GET
https://probability-calc.x402tookit.com/distribution-table
Price
$0.02
per call in USDC
Uptime
64.3%
last 30 days
Response time
556 ms
974 ms slowest 5%
Last check
Passed
5 h ago, next in 1 h

Run a free test callHow to call it

Reliability

All checks passedSome failedAll failedNot checked

Status and outage history · Atom feed · Watch with other listings

How to call it

GET https://probability-calc.x402tookit.com/distribution-table

Each call costs $0.02 in USDC on Polygon, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

GET https://probability-calc.x402tookit.com/distribution-table?K=13&N=52&dist=hypergeometric&n=5

Parameters

ParameterTypeRequiredDescription
KintegerNoSuccesses in the population (hypergeometric)
NintegerNoPopulation size (hypergeometric), up to 1e6
diststringYesOne of geometric, negative-binomial, hypergeometric, binomial, poisson
kintegerNoOptional point of interest: adds pmf, P(X<=k) and P(X>=k) for this k
lambdanumberNoMean rate (Poisson), 0 to 1000
nintegerNoTrials (binomial) or draws (hypergeometric)
pnumberNoSuccess probability (geometric, negative-binomial, binomial)
rintegerNoSuccesses wanted (negative-binomial), 1 to 1000

Example response

The provider's example. We can't check it without paying.

Example response, 43 lines
{
  "asOf": "2026-10-11T14:44:17.625Z",
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "distribution": "hypergeometric",
  "mean": 1.25,
  "mode": 1,
  "notChecked": [
    "sampling with versus without replacement (geometric, binomial and negative binomial assume independent trials; hypergeometric is without replacement)",
    "tables are cut to the first 60 rows or the point where the remaining tail is below 1e-9 (the full cumulative is exact)",
    "…1 more"
  ],
  "parameters": {
    "K": 13,
    "N": 52,
    "n": 5
  },
  "reasons": [
    "Probabilities are computed in log space from exact formulas; columns are pmf, cumulative P(X<=k) and upper tail P(X>=k).",
    "All values assume the stated parameters are exact."
  ],
  "source": "computed locally (exact formulas in log space)",
  "standardDeviation": 0.92950018,
  "summary": "hypergeometric: mean 1.25, variance 0.86397059, sd 0.92950018, mode 1.",
  "support": "k = 0 to 5 (successes in 5 draws without replacement)",
  "table": [
    {
      "cumulative": 0.22153361,
      "k": 0,
      "probability": 0.22153361,
      "upperTail": 1
    },
    {
      "cumulative": 0.63295318,
      "k": 1,
      "probability": 0.41141957,
      "upperTail": 0.77846639
    }
  ],
  "tableComplete": true,
  "variance": 0.86397059,
  "verdict": "TABLE"
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.02.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://probability-calc.x402tookit.com/distribution-table?K=13&N=52&dist=hypergeometric&n=5'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://probability-calc.x402tookit.com/distribution-table?K=13&N=52&dist=hypergeometric&n=5' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fprobability-calc.x402tookit.com%2Fdistribution-table
const res = await pay("https://probability-calc.x402tookit.com/distribution-table?K=13&N=52&dist=hypergeometric&n=5");
console.log(res.status, await res.text());
Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://probability-calc.x402tookit.com/distribution-table?K=13&N=52&dist=hypergeometric&n=5")
    print(res.status_code, res.text)

Security scan

No findings

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Recent checks

WhenResultHTTPTimePrice
5 h agoPassed402571 ms$0.02
17 h agoPassed402572 ms$0.02
2 days agoExpected HTTP 402, got 530530102 ms-
3 days agoExpected HTTP 402, got 530530136 ms-
5 days agoExpected HTTP 402, got 53053098 ms-
Show 9 older checks
5 days agoExpected HTTP 402, got 530530199 ms-
5 days agoExpected HTTP 402, got 530530146 ms-
5 days agoPassed402494 ms$0.02
5 days agoPassed402546 ms$0.02
6 days agoPassed402556 ms$0.02
6 days agoPassed402683 ms$0.02
6 days agoPassed402974 ms$0.02
6 days agoPassed402519 ms$0.02
7 days agoPassed402407 ms$0.02