Rain SDK Documentation

Overview

Rain SDK is designed as a clean, modular, and extensible TypeScript SDK for interacting with Rain markets and preparing on-chain transactions.

The SDK is intentionally split into two layers:

* Rain → Stateless, public-facing utilities (data fetching, raw transaction builders)
* RainAA → Stateful Account Abstraction layer (smart accounts)

---

Installation

``bash
npm install @rainprotocolsdk/sdk
`

or

`bash
yarn add @rainprotocolsdk/sdk
`

---

$3

`ts
import { Rain } from "@rainprotocolsdk/sdk";

const rain = new Rain();
`

> The constructor is intentionally empty to allow future configuration without breaking changes.

---

getPublicMarkets

Fetches public market data from the Rain backend.

$3

`ts
getPublicMarkets(params: GetMarketsParams): Promise;
`

$3

`ts
interface GetMarketsParams {
limit: number;
offset: number;
sortBy?: "Liquidity" | "Volumn" | "latest";
status?: 'Live' | 'New' | 'WaitingForResult' | 'UnderDispute' | 'UnderAppeal' | 'ClosingSoon' | 'InReview' | 'InEvaluation' | 'Closed' | 'Trading';
}
`

$3

`ts
const markets = await rain.getPublicMarkets({
limit?: 12,
offset?: 1,
sortBy?: "Liquidity",
status?: "Live",
});
`

---

buildApprovalTx

`
Builds a raw ERC20 approval transaction if needed.

This function prepares an unsigned approve(spender, amount) transaction and does not execute it.

If amount is not provided, a default large allowance is approved.
`

$3

`ts
interface RawTransaction {
to: 0x${string};
data: 0x${string};
}
`

$3

`ts
const approvalTx = rain.buildApprovalTx({
tokenAddress: 0x${string}, // Approval token address
spender: 0x${string}, // Market contract address
amount?: 1000000000000000000n // optional parameter
});
`

---

buildBuyOptionRawTx

Builds a raw EVM transaction for entering a market option.

This function does not send the transaction — it only prepares calldata.

$3

`ts
buildBuyOptionRawTx(params: EnterOptionTxParams): RawTransaction;
`

$3

`ts
interface EnterOptionTxParams {
address: 0x${string}; // Trademarket contract address
selectedOption: number; // Option index
buyInWei: bigint; // Amount in wei
}
`

$3

`ts
interface RawTransaction {
to: 0x${string};
data: 0x${string};
}
`

$3

`ts
const rawTx = rain.buildBuyOptionRawTx({
address: 0x${string},
selectedOption: 1,
buyInWei: 1000000000000000000n,
});
`
---

buildLimitBuyOptionTx

Builds a raw EVM transaction for placing a limit buy order on a Rain market.

This function does not send the transaction — it only prepares calldata.

$3

`ts
buildLimitBuyOptionTx(params: EnterLimitOptionTxParams): RawTransaction
`

$3

`ts
interface EnterLimitOptionTxParams {
marketContractAddress: 0x${string}; // market contract address
selectedOption: number; // Option index
pricePerShare: bigint; // price per share
buyAmountInWei: bigint; // total buy amount (already converted to token wei)
tokenDecimals?: number; // token decimals optional (default: 6)
}
`


$3

| Field | Type | Required | Description |
| ----------------------- | ------------- | -------- | ------------------------------------------------------ |
| marketContractAddress | 0x${string} | ✅ | Address of the market contract |
| selectedOption | number | ✅ | Option index to place the buy order for |
| pricePerShare | number | ✅ | Limit price per share (between 0 and 1) |
| buyAmountInWei | bigint | ✅ | Total amount to spend (already converted to token wei) |
| tokenDecimals | number | ❌ | Token decimals optional (default: 6) |

$3

`ts
interface RawTransaction {
to: 0x${string};
data: 0x${string};
}
`

$3

`ts
rain.buildLimitBuyOptionTx({
marketContractAddress: 0x${string},
buyAmountInWei: 1000000,
pricePerShare: 0.1,
selectedOption: 1,
})
`

---

RainAA Class (Account Abstraction)

RainAA is responsible for:

* Smart account creation
* Session management (coming soon)
* Gas-sponsored execution (coming soon)
* Transaction submission (coming soon)

> RainAA consumes raw transactions generated by Rain.

$3

`ts
Rain (WHAT to do)
↓
Raw Transaction
↓
RainAA (HOW to execute)
`

Versioning Policy

Rain SDK follows Semantic Versioning:

* Patch (1.0.x) → Bug fixes
* Minor (1.x.0) → New features, backward compatible
* Major (x.0.0) → Breaking API changes

---

Recommended Usage Pattern

`ts
// 1. Read data / build tx
const rain = new Rain();
const rawTx = rain.buildBuyOptionRawTx(...);

// 2. Execute via your provider
await yourprovider.sendTransaction(rawTx);
``

---

Rain SDK is built to scale with both products and protocols.