Build on native outcome primitives.

Networks

Network endpoints

Planned interfaces: REST and WebSocket APIs for books (L2 depth and order-level L3), fills and user state; EVM JSON-RPC; an indexer streaming every fill and event; a Blockscout explorer for RainEVM and a RainCore explorer for markets, books, fills, validators and the bridge queue. A public status page will show block production, validator uptime and the bridge queue.

Accounts & signing

One key, two engines

• Accounts are secp256k1 addresses — the same key controls RainCore and RainEVM balances. Existing EVM wallets work.
• RainCore actions are EIP-712 typed messages, not EVM transactions. Trading is gasless.
• Each action carries a nonce: signers keep their 100 highest nonces; a new nonce must exceed the smallest, be unused, and lie within (T − 2 days, T + 1 day) of block time in ms. A millisecond timestamp works well.
• Optional expiresAfter: the action is rejected if included after this time.
• Agent keys let bots trade without holding withdrawal rights: up to 10 per account, scoped trade or cancel-only, expiring in ≤ 180 days. They share the master's rate-limit budget.

EIP-712 domain, chain id and type definitions: TBA with devnet.

API

Action types

Every action is classified by the in-block ordering rule (class 1 = non-taking, 2 = cancel, 3 = taker). Names below are descriptive; final wire names ship with the SDK.

Rate limits: 10,000-request initial buffer plus 1 request per $1 of filled volume; cancels get min(limit + 100,000, 2 × limit). Batches count as n requests.

Examples

What integration will look like

// Illustrative only — not a published SDK.
import { RainClient } from "@rain/sdk";       // placeholder package

const rain = new RainClient({
  rpc: process.env.RAIN_REST_URL,                // TBA — no public network yet
  signer: agentKey,                              // scope: "trade", expires ≤ 180 days
});

// Every action is an EIP-712 typed message, gasless on RainCore.
await rain.batch([
  { type: "cancelByCloid", market, cloid: "0x…01" },
  { type: "order", market, side: "buyYes", price: 0.412, size: 5_000,
    tif: "ALO", cloid: "0x…02" },              // post-only: class 1
  { type: "order", market, side: "buyNo",  price: 0.586, size: 5_000,
    tif: "ALO", cloid: "0x…03" },              // stored as sell YES @ 0.414
]);

// Dead-man switch: cancel everything if we go quiet for 10 s.
await rain.scheduleCancel({ at: Date.now() + 10_000 });

// Illustrative only.
rain.ws.subscribe({ channel: "l2Book", market }, (book) => {
  // Prices are YES prices on one merged book; NO = 1 − YES.
  render(book.bids, book.asks);
});

// Illustrative only — precompile address and interface TBA.
interface IRandom {
  function request(uint64 k) external returns (uint256 id);   // k ≥ 2, default 3
  function get(uint256 id) external view returns (bytes32);  // reverts until round final
}

contract Dice {
  IRandom constant RNG = IRandom(RANDOM_PRECOMPILE);         // TBA
  function roll() external returns (uint256 id) { id = RNG.request(3); }
  function settle(uint256 id) external {
    uint256 r = uint256(RNG.get(id)) % 6 + 1;                  // commit-then-reveal
    // … pay out, capped at a fraction of vault equity
  }
}

RainEVM

Contracts with access to RainCore

EVM-equivalent (Cancun-level, revm), gas in RAIN with EIP-1559 (base fee burned), ERC-4337 EntryPoint and paymasters at genesis. Precompiles: CoreRead, CoreWrite (queued to the next block in class order), Random, Resolve and Stake. Block gas target 15M, limit 30M per 200 ms block (target). See Technology → RainEVM.

Open-source, audited templates are planned: House Vault, dice, scheduled lottery and a crash-style game. Operators deploy and run their own instances; Rain provides infrastructure.

SDK

SDK & tooling

Bridge

Moving assets from Arbitrum One

Withdrawals need signatures from ≥ 2/3 of stake and stay under outflow caps of 5% of the lockbox per hour (20% per day). Validators and independent guardians can lock the bridge if a withdrawal doesn't match chain state; unlocking needs a quorum of validator cold keys, and guardians can never move funds. Two independent audits and formal verification of the signature logic are required before mainnet. Contract addresses: TBA

Reference

Read the specification

The Layer 1 specification v0.2 is the source of truth for every parameter on this site.

Read the specification (PDF) → Documentation hub