rng.dev Documentation

1-second public randomness beacon backed by 8 blockchains

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What is rng.dev?

rng.dev is a public random number beacon that:

• Generates new randomness every second
• Fetches entropy from 8 independent blockchains (block hashes + transaction IDs)
• Requires $80 billion+ to compromise (economic security)
• Allows anyone to independently verify any round
• Is fully open source — self-host or use the API

Sources

Chain	Finality	Role
Aptos	~900ms	Fresh each round
Arbitrum	~250ms	Fresh each round
Base	~2s	Fresh each round
Bitcoin	~60 min	Stable base entropy
Cardano	~20s	Stable base entropy
Ethereum	~15 min	Stable base entropy
Solana	~400ms	Fresh each round
Sui	~400ms	Fresh each round

Fast-finality chains (Aptos, Arbitrum, Base, Solana, Sui) provide fresh data every second. Slower chains provide stable base entropy. Transaction IDs provide information-theoretic unpredictability.

Key Properties

Property	Description
Transparent	All inputs are public blockchain data
Multi-source	No single point of failure or manipulation
Verifiable	Anyone can recompute any historical round
Open source	Fork and run your own beacon

Documentation

Getting Started

• How It Works - Understanding the beacon
• Quick Start - Using the API
• Verification Guide - Verify any round
• Statistical Tests - Randomness validation

API Reference

• REST API - Endpoints and schemas
• WebSocket - Real-time updates

Security

• Threat Model - Trust assumptions and attack analysis
• Appropriate Use Cases - What this is (and isn't) for

Self-Hosted

• Running Your Own Beacon - Fork and deploy

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Quick Example

# Get current random value
curl https://rng.dev/api/v1/current

# Response
{
  "round": 12345678,
  "output_hash": "a3f2e8c9d1b4a5c6d7e8f9...",
  "die_value": 4,
  "generated_at": "2026-03-09T15:00:00Z",
  "status": "complete",
  "sources_available": 8
}

API Access

Tier	Limit
Unauthenticated	100/day
Authenticated	10,000/day

Sign in with Google or GitHub to get an API key. Self-hosted is always free.

Open Source

rng.dev is open source under MIT license.

GitHub: github.com/rngdev/beacon

Contact

• Support: rng.dev/contact (sign-in required)
• Twitter: @rngdev