SDK Overview

Use the Rain SDK to interact with the Rain API in TypeScript, Go, or Python. You get full type safety, IDE autocomplete, and a consistent interface across every language. Follow these steps to go from SDK installation to your first call:

Install the SDK

In your terminal, run:

npm install @rainapi/rain-sdk

go get -u github.com/SignifyHQ/rain-sdk-go@v0.1.0

pip install rain-sdk

The SDK is optional. You can make all the same calls directly to the Rain REST API using any HTTP client. See Authenticating with the API for details.

Initialize the client

Create a client instance by passing your API key and choosing your environment. Your API key defaults to the RAIN_API_KEY environment variable.

import Rain from '@rainapi/rain-sdk';

const client = new Rain({
  apiKey: process.env['RAIN_API_KEY'],
  environment: 'dev', // use 'production' for live
});

package main

import (
	"context"
	"fmt"
	"os"

	rainsdk "github.com/SignifyHQ/rain-sdk-go"
	"github.com/SignifyHQ/rain-sdk-go/option"
)

func main() {
	client := rainsdk.NewClient(
		option.WithAPIKey(os.Getenv("RAIN_API_KEY")),
		option.WithEnvironmentDev(), // use option.WithEnvironmentProduction() for live
	)
	_ = client
}

from rain_sdk import Rain

client = Rain(
    api_key="your-api-key",  # defaults to RAIN_API_KEY env var
    environment="dev",       # use "production" for live
)

Parameter	Default	Description
`apiKey`	`RAIN_API_KEY` env var	Your API key from the Developer Dashboard
`environment`	`dev`	`'dev'` for sandbox, `'production'` for live

In Go, select the environment with option.WithEnvironmentDev() or option.WithEnvironmentProduction() instead of a string.

Make your first call

List your companies to verify the SDK is working:

const companies = await client.companies.list();
console.log(companies);

companies, err := client.Companies.List(context.TODO(), rainsdk.CompanyListParams{})
if err != nil {
	panic(err)
}
fmt.Println(companies)

companies = client.companies.list()
print(companies)

Explore the API

The SDK organizes all endpoints into resource namespaces that mirror the API Reference:

Namespace	Description
`client.applications`	Submit and manage KYC/KYB applications
`client.balances`	Retrieve credit balances
`client.cards`	Create, update, and list cards
`client.companies`	Manage companies, users, and payments
`client.contracts`	View smart contract details
`client.disputes`	File and manage disputes
`client.keys`	Create and delete API keys
`client.payments`	Initiate payments
`client.signatures`	Retrieve payment and withdrawal signatures
`client.transactions`	List, filter, and update transactions
`client.users`	Create and manage users

Type client. in your IDE to see all available namespaces, then type client.cards. to see the methods on that resource. Every method maps directly to an endpoint in the API Reference.

In Go, namespaces are PascalCase fields on the client: client.Cards, client.Transactions, client.Applications.User, and so on.

Type safety

Import request and response types for full type safety. In Go, optional fields use param.Opt[T] wrappers — construct them with helpers like rainsdk.String(...) and rainsdk.Int(...), and check response field presence with .JSON.<Field>.Valid().

import Rain from '@rainapi/rain-sdk';

// Request params
const params: Rain.UserCreateCardParams = {
  type: 'virtual',
  limit: { amount: 50000, frequency: 'per30DayPeriod' },
};

// Response types
const card: Rain.IssuingCard = await client.users.createCard(userId, params);
console.log(card.last4, card.status);

// Request params
params := rainsdk.UserNewCardParams{
	Type: rainsdk.UserNewCardParamsTypeVirtual,
	Limit: rainsdk.IssuingCardLimitParam{
		Amount:    50000,
		Frequency: rainsdk.IssuingCardLimitFrequencyPer30DayPeriod,
	},
}

// Response types
card, err := client.Users.NewCard(context.TODO(), userID, params)
if err != nil {
	panic(err)
}
fmt.Println(card.Last4, card.Status)

What’s next

Configuration

Set up error handling, retries, timeouts, and logging.

Card Issuance

Issue your first card end-to-end with the SDK.

Embedded Wallets

Add non-custodial embedded wallets to your Android or iOS app.

Welcome

Core Concepts

Quickstart

Platform Policies

Go Live

SDK Overview

Explore the API

Type safety

What’s next

Configuration

Card Issuance

Embedded Wallets

​Explore the API

​Type safety

​What’s next

Configuration

Card Issuance

Embedded Wallets

Explore the API

Type safety

What’s next