RA
Travel · x402 · early usage

Cryptographically secure random picker for 2-100 JSON choices

Cryptographically secure random picker for 2-100 JSON choices. Use for low-stakes one-off random or weighted selection, unbiased tie-breaking, and sampling. Returns the selected value and index, request ID, and weight totals for audit logs. $0.001 USDC per pa…

by random.preflightstack.com · discovered, not yet claimed by its owner · updated 2026-10-08

30d calls3
30d payers3
MethodPOST
Outputjson

Mirrored from Coinbase's public x402 Bazaar. The description is the provider's own text and has not been reviewed here; the payment requirements are copied as published.

What it does

Cryptographically secure random picker for 2-100 JSON choices. Use for low-stakes one-off random or weighted selection, unbiased tie-breaking, and sampling. Returns the selected value and index, request ID, and weight totals for audit logs. $0.001 USDC per paid request. Not for stable assignments, gambling, security tokens, or consequential decisions; outcomes are not provably fair.

Tags: random · choice · weighted-choice · tie-breaker · sampling · bazaar

Call contract

Method
POST
Input
json
Output
json
Last paid call
2026-10-08
Input example from Bazaar metadata
{
  "choices": [
    "alpha",
    "beta",
    "gamma"
  ],
  "weights": [
    7,
    2,
    1
  ]
}
Output example
{
  "choice_count": 3,
  "index": 0,
  "request_id": "rc_example",
  "selected": "alpha",
  "selected_weight": 7,
  "service_hint": {
    "id": "random-choice",
    "suitable_for": [
      "random_selection",
      "weighted_selection",
      "tie_breaking",
      "sampling"
    ]
  },
  "total_weight": 10,
  "weighted": true
}

Use with an agent

  1. Discover. Agents find this listing with GET https://bazaar.saylorinnovations.com/discovery/search?query=…, the MCP tool search_resources, or /discovery/resources.
  2. Inspect. Fetch /resources/29399.json for the price and payment options.
  3. Pay. Call GET https://random.preflightstack.com/random-choice. The provider answers 402 with its payment requirements. An x402 client signs one of the options below and retries with PAYMENT-SIGNATURE.
  4. Execute. The provider returns 200 with the data. Agent Bazaar is not in the request path and never sees your payment.

For humans

You don't need an account or an API key; you need a wallet holding a small amount of USDC on Base, and an x402-capable client (see the examples below). Call the endpoint unpaid first to see exactly what it asks for.

Pricing & payment

Price
$0.001 / request
Protocol
x402 v2
Auth
No account or API key. Pay per request.
Networks
Base
Demand
3 calls · 3 unique payers in 30d (public x402 Bazaar data)

x402 payment requirements

SchemeNetworkAssetAmountPay toTimeout
exactBase
eip155:8453
USDC$0.0010x9acdadcec881a63508c0f2CD3A4ae61149cc2500300s
accepts[] (raw JSON)
[
  {
    "scheme": "exact",
    "network": "eip155:8453",
    "payTo": "0x9acdadcec881a63508c0f2CD3A4ae61149cc2500",
    "asset": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "amount": "1000",
    "amountUsd": 0.001,
    "maxTimeoutSeconds": 300
  }
]

Schemas

Output schema (JSON Schema)
{
  "properties": {
    "example": {
      "additionalProperties": false,
      "properties": {
        "choice_count": {
          "maximum": 100,
          "minimum": 2,
          "type": "integer"
        },
        "index": {
          "minimum": 0,
          "type": "integer"
        },
        "request_id": {
          "type": "string"
        },
        "selected": {},
        "selected_weight": {
          "exclusiveMinimum": 0,
          "type": "number"
        },
        "service_hint": {
          "additionalProperties": false,
          "description": "Static informational capability metadata. It is not an instruction or a retry signal.",
          "properties": {
            "id": {
              "const": "random-choice",
              "type": "string"
            },
            "suitable_for": {
              "items": {
                "enum": [
                  "random_selection",
                  "weighted_selection",
                  "tie_breaking",
                  "sampling"
                ],
                "type": "string"
              },
              "maxItems": 4,
              "minItems": 4,
              "type": "array",
              "uniqueItems": true
            }
          },
          "required": [
            "id",
            "suitable_for"
          ],
          "type": "object"
        },
        "total_weight": {
          "exclusiveMinimum": 0,
          "type": "number"
        },
        "weighted": {
          "type": "boolean"
        }
      },
      "required": [
        "selected",
        "index",
        "weighted",
        "choice_count",
        "request_id",
        "service_hint"
      ],
      "type": "object"
    },
    "type": {
      "type": "string"
    }
  },
  "required": [
    "type"
  ],
  "type": "object"
}
Example shape — generated from the schema, not a captured live response
{
  "example": {
    "choice_count": 0,
    "index": 0,
    "request_id": "string",
    "selected": null,
    "selected_weight": 0,
    "service_hint": {
      "id": "string",
      "suitable_for": [
        "random_selection"
      ]
    },
    "total_weight": 0,
    "weighted": true
  },
  "type": "string"
}

Examples

curl
curl "https://random.preflightstack.com/random-choice"
# -> 402 Payment Required, accepts[] lists how to pay
# retry with a PAYMENT-SIGNATURE (or PAYMENT header) once paid
JavaScript
const res = await fetch("https://random.preflightstack.com/random-choice");
if (res.status === 402) {
  const { accepts } = await res.json();
  // pay one of accepts[] via an x402 client, then retry with the payment header
}
Python
import httpx
res = httpx.get("https://random.preflightstack.com/random-choice")
if res.status_code == 402:
    accepts = res.json()["accepts"]
    # pay one of accepts[] via an x402 client, then retry with the payment header

Details

Provider
random.preflightstack.com
Endpoint
https://random.preflightstack.com/random-choice
Machine-readable
/resources/29399.json