autorenew

Shuffle & Sample

Operational

Verifiably shuffle or randomly sample from any list using Fisher-Yates seeded by drand

API Overview

The shuffle endpoint implements the Fisher-Yates algorithm seeded deterministically from the drand beacon. Submit any JSON array (strings, numbers, objects) and receive it fully shuffled or a random sample of k items without replacement. The beacon proof lets any party verify the shuffle was produced from public randomness — ideal for lotteries, competition brackets, and order-randomised surveys. Lists up to 10,000 items are supported per call.

autorenew

Fisher-Yates Shuffle

Mathematically unbiased full shuffle or partial sample — each permutation is equally likely.

verified

Public Randomness Source

The drand beacon is distributed across 20+ independent operators — no single point of bias.

data_object

Any JSON Array

Accepts strings, numbers, or nested objects — the API shuffles your data as-is.

shield

Audit Trail

Store the beacon proof alongside your draw results to settle any dispute without a trusted arbiter.

integration_instructions API Reference

data_object openapi.json open_in_new Swagger UI

data_object

OpenAPI Spec

openapi.json

open_in_new

description

Swagger UI

Interactive API explorer

open_in_new

POST /api/random/shuffle

Body Parameters

Parameter	Type	Required	Description
`items`	array	Yes	Array of items to shuffle (max 10,000 elements)
`pick`	integer	No	Number of items to select (default: all — full shuffle)

terminal API Playground

Live Simulation

items * (array)

pick (integer)

import requests

url = "https://random.picopayd.codefission.co.uk/api/random/shuffle"
payload = {"items": ["alice", "bob", "carol", "dave"], "pick": 2}
headers = {
    "Content-Type": "application/json",
    "X-PAYMENT": "<402-payment-token>"
}

response = requests.post(url, json=payload, headers=headers)
print(response.json())

const response = await fetch(
  "https://random.picopayd.codefission.co.uk/api/random/shuffle",
  {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      "X-PAYMENT": "<402-payment-token>"
    },
    body: JSON.stringify({ items: ["alice", "bob", "carol", "dave"], pick: 2 })
  }
);
const data = await response.json();
console.log(data);

curl -X POST "https://random.picopayd.codefission.co.uk/api/random/shuffle" \
  -H 'Content-Type: application/json' \
  -H 'X-PAYMENT: <402-payment-token>' \
  -d '{"items": ["alice", "bob", "carol", "dave"], "pick": 2}'

Response Body 200 OK

{
  "result": ["carol", "alice"],
  "totalItems": 4,
  "picked": 2,
  "proof": {
    "round": 21543892,
    "signature": "95a9...",
    "chainHash": "52db9b...",
    "timestamp": "2026-03-20T10:00:00Z"
  }
}