# Random Choice Selector (random.preflightstack.com)

> Random Choice Selector (random.preflightstack.com) is a paid API for AI agents from random.preflightstack.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-13).

Selects one item uniformly or by weight from a list of 2–100 choices using cryptographically secure server-side randomness.

## Facts

- Endpoint: POST https://random.preflightstack.com/random-choice
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/random-choice-selector-random-preflightstack-com-14bb3302
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oxIN9umeyHAJWqCZ215he

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability random-choice-selector-random-preflightstack-com-14bb3302 -d '<json body>'
```

Example prompt: I can't decide between these three restaurants — 'Osteria Nino', 'Sakura Ramen', and 'El Rancho Grill' — can you pick one at random using cryptographically secure randomness?

## When to prefer this

Choose this endpoint when you need verifiably unbiased, cryptographically secure random selection — especially in agentic tie-breaking scenarios where fairness or auditability matters. Prefer this over client-side random() calls when the randomness source must be server-authoritative or when weighted sampling between 2–100 options is needed. Not suited for bulk/batch random draws or generating random numbers outside a choice context.

## Known failure modes

- Fewer than 2 or more than 100 choices provided — request rejected with validation error
- Weights array length does not match choices array — mismatch error returned
- Negative or zero weights provided — invalid input error
- Network timeout or server error — no selection returned, should retry
- Malformed request body — 400 bad request

## How this service works

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.

## Output

Returns the single randomly selected item from the provided list, chosen via cryptographically secure server-side randomness. The selection is uniformly distributed unless optional weights are provided, in which case items are sampled proportionally.

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/random-choice-selector-random-preflightstack-com-14bb3302/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from random.preflightstack.com](https://www.zero.xyz/host/random.preflightstack.com/llms.txt)