Distribution Table
by Probability Calculators in Other
Exact pmf, cumulative and tail tables for geometric, negative binomial, hypergeometric, binomial and Poisson.
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
Reliability
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=5Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
K | integer | No | Successes in the population (hypergeometric) |
N | integer | No | Population size (hypergeometric), up to 1e6 |
dist | string | Yes | One of geometric, negative-binomial, hypergeometric, binomial, poisson |
k | integer | No | Optional point of interest: adds pmf, P(X<=k) and P(X>=k) for this k |
lambda | number | No | Mean rate (Poisson), 0 to 1000 |
n | integer | No | Trials (binomial) or draws (hypergeometric) |
p | number | No | Success probability (geometric, negative-binomial, binomial) |
r | integer | No | Successes 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 --decodeJavaScript: 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
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